CLINICAL MICROBIOLOGY AND INFECTIOUS DISEASES Original Article
Fatal Disseminated Conidiobolus coronatus Infection in a Renal Transplant Patient SUE D. WALKER, M.D., 1 RODERICK V. CLARK, M.D., 2 COLEMAN T. KING, M.D., 3 JOE E. HUMPHRIES, P H . D . , 1 LINDA S. LYTLE, M.T.(ASCP), 1 AND DONALD E. BUTKUS, M.D. 2
called the Splendore-Hoeppli phenomenon. The histologic findings in the present case were more typical of mucormycosis, and the correct diagnosis was established only after the organism was isolated and identified in culture. (Key words: Entomophthorales; Conidiobolus coronatus; Disseminated zygomycosis) Am J Clin Pathol 1992; 98:559-564
In recent years, opportunistic infections have become commonplace because there are more immunosuppressed patients who are susceptible to infection by a variety of microorganisms, including eukaryotes, prokaryotes, and viruses. Some of these organisms are known pathogens, whereas others are strict opportunists, and the infections they cause range from localized colonization to lethal dissemination. Of these organisms, the fungi have emerged as significant threats to persons with altered states of immunity. Although many of the fungal pathogens are well described, recent case reports have documented overwhelming infections caused by unusual fungi, such as dermatophytes, which were once thought to be relatively harmless. Disseminated infections caused by the genera Fusarium, Malassezia, Pseudallescheria, Scedosporium, and Trichosporon1 have now been reported. In addition, rare and exotic fungi, little known outside circles of professional mycologists, now sometimes produce clinical disease.
Recently we encountered a renal transplant patient with disseminated infection due to an unusual fungus, Conidiobolus coronatus, which typically causes localized nasal and soft-tissue infections in animals and humans, especially in tropical and subtropical regions. Our case was associated with simultaneous infection with two more conventional opportunists, Histoplasma capsulatum and cytomegalovirus. We describe this case and review other cases of human Conidiobolus infection reported in the literature. CASE REPORT
A 64-year-old man was transferred to our facility from an outlying hospital in July 1990 for evaluation of fever, pancytopenia, and pneumonia. The patient had a history of end-stage renal disease secondary to hypertension and had received a cadaveric renal transplant in 1983. He had been given maintenance drug therapy of imuran and prednisone, with creatinine values of 88 to 132 jumol/L. The patient's present symptoms began 3 months before admission, with anorexia, severe gingivitis, and a 35-pound weight loss. Shortly before he came to our hospital, he developed a low-grade fever and was treated with a 10-day course of oral antibiotics. The patient was admitted to his local hospital with streaky hemoptysis, From the University of Mississippi Medical Center, Departments of fever, chills, and pleuritic chest pain. He had a temperature of 40 °C, 2 'Pathology and Medicine. Divisions of Nephrology and ^Infectious Dis- gingival hyperplasia, and rales. Chest x-ray demonstrated bilateral lower eases, Jackson, Mississippi. lobe infiltrates. His white blood cell count was 1,300/mm3, with 21% segmented neutrophils, 53% banded neutrophils, 21% lymphocytes, \% Received November 8, 1991; revised manuscript accepted for publimonocytes, and 4% eosinophils. Hematocrit concentration was 45% and cation March 5, 1992. platelet count was 7,000/mm3. A gingival biopsy was performed and the Address correspondence to Dr. Sue Walker: Department of Pathology, patient was transferred to our center after 3 days of hospitalization for University of Mississippi Medical Center, 2500 North State Street, Jackfurther evaluation. son, Mississippi 39216.
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A case of fatal disseminated fungal infection due to Conidiobolus coronatus in a patient with a renal transplant is described. This organism, known to cause localized infections in otherwise healthy individuals in the tropics, is now recognized as a cause of fatal infection in immunosuppressed hosts. Histologically, localized infections are characterized by lack of vessel invasion and the presence of an eosinophilic sleeve around fungal elements,
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FIG. 1 (upper). Chest x-ray revealing a circumscribed pulmonary infiltrate that partially obscures the left lateral cardiac border. FIG. 2 (lower). Chest x-ray taken approximately 2 weeks after the chest x-ray shown in Figure 1. The expanded infiltrate in the left lung now contains a central lucency as a result of cavitation.
PATHOLOGIC FINDINGS At autopsy the inferior aspect of the upper lobe of the left lung contained a cavitary infarct measuring 7 X 5 X 5 cm (Fig. 3). The cavity contained necrotic tissue remnants and the surrounding lung tissue was firm and congested. The right lung contained several 1-cm rounded, tan lesions scattered throughout the parenchyma (Fig. 4). Cut sections of the myocardium revealed multiple red lesions measuring less than 2 mm that resembled petechiae. The right coronary artery was occluded just distal to its origin by recent thrombus. The renal allograft was enlarged and hydronephrotic, and cut sections revealed multiple hemorrhagic infarcts with abscess formation.
Coronal sections of the brain revealed multiple discrete lesions varying from 3 to 6 mm in both basal ganglia, and a 3-mm pale red lesion was found in the right upper red nucleus. The right posterior cerebellum contained a 3.5cm, dark, partially hemorrhagic infarct. Microscopic examination of multiple sections from all lung fields showed abscesses that contained abundant fragmented hyphae, which were visible with both hematoxylin and eosin and Gomori methenamine silver stains. The hyphal fragments were broad, frequently septate, and appeared hollow. The abscesses were composed primarily of neutrophils. The necrotic cavity in the left lung con-
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At physical examination, we noted that this elderly patient was frail and lethargic, although he responded appropriately. His body temperature was 37.8 °C. Examination of the chest revealed rales and wheezing. Results of an abdominal examination were normal and no peripheral adenopathy was noted. Symmetrical muscle wasting was observed in the lower extremities, but the neurologic examination was unremarkable. A chest x-ray showed bilateral lower lobe infiltrates. Pertinent laboratory values included a blood urea nitrogen level of 24.9 mmol/L and creatinine value of 309 ftmol/L. Arterial blood gases obtained on 2 L of oxygen via nasal canula were pH 7.50, Pco2 27 mmHg, and P02 51 mmHg. Review of the slides from the patient's gingival biopsy indicated a diagnosis of histoplasmosis, and antifungal therapy with amphotericin B was begun. Immunosuppressive therapy with imuran and prednisone was continued. A bone marrow aspirate and biopsy revealed a hypocellular marrow with negative fungal stains; however, cultures of this marrow grew Histoplasma capsulatum. On the fourth hospital day, the patient was afebrile and his appetite had returned. Amphotericin B was continued at a dose of 50 mg every other day, and he continued to improve subjectively as well as objectively: the chest x-ray and oxygenation improved; creatinine level decreased to 158.9 jimol/L, the white blood cell count increased to 11,000, and the platelet count increased to 54,000/mm3. Three weeks after admission, a Broviac catheter was placed to facilitate amphotericin B infusions in anticipation of outpatient therapy. Two days after this procedure, the patient's body temperature increased to 38.3 °C, his blood pressure decreased to 90/60 mmHg, and dyspnea developed. Repeated chestfilmsrevealed a new left lower lobe infiltrate (Fig. 1), and arterial blood gases measured on room air were pH 7.51, PCOJ 55 mmHg and P02 50 mmHg. Intravenous mezlocillin and gentamicin were given, and amphotericin B was continued. A fever of 39 °C persisted while the patient was taking this drug regimen, and after 3 days vancomycin was added. Fiberoptic bronchoscopy was performed and cytologic examination of bronchial washings revealed hemosiderin-laden macrophages andfilamentssuggesting an Aspergillus sp. Gram's stain and acid-fast smears were negative. Bacterial and fungal cultures of fiberoptic bronchoscopy washings were negative as well. The patient's respiratory status continued to decline, with worsening hypoxemia and progressive pulmonary infiltrates evident on chest x-ray. Five weeks after admission, acute respiratory distress developed that required intubation and mechanical ventilation. Although he was stabilized initially, anasarca and hypotension developed and urine output decreased. Repeated fiberoptic bronchoscopy washings revealedfilamentousorganisms resembling a zygomycete. Chest x-ray revealed a lucency within the left lung infiltrate (Fig. 2). Diagnostic open lung biopsy was in progress when cardiopulmonary arrest occurred and the patient died. An autopsy was performed.
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FIG. 4 (lower). Right lung shows multiple 1-cm tan nodules (arrows). Microscopically these areas contained cells with intranuclear inclusions characteristic of cytomegalovirus infection. Hyphae were not found in these lesions.
tained inflammatory cell debris and many fungal elements. Examination of the adjacent parenchyma revealed fungal hyphae within alveolar spaces, with invasion of pulmonary vessel walls. Cells with intracytoplasmic and Cowdry type A intranuclear inclusions compatible with cytomegalovirus infection were seen in slides from the small nodules in the right lung, but hyphae were not found in these lesions. Microabscesses containing angioinvasive fungal elements, similar to those in the lungs, also were found in the right coronary artery thrombus, myocardium, brain, renal allograft, and thyroid. Of interest, the fungal hyphae were not enveloped by Splendore-Hoeppli material (Figs. 5 and 6). MICROBIOLOGIC METHODS AND FINDINGS All specimens obtained at surgery and autopsy were cultured on Sabouraud's dextrose agar with and without
chloramphenicol, mycosel agar, and trypticase soy agar with 5% sheep blood, chocolate, and MaConkey agar. After 2 days at room temperature, fungal growth on Trypticase soy agar with 5% sheep blood occurred in the culture of bronchial washings. Subsequently, identical growth occurred in both routine and fungal media from the following specimens: pleural fluid, lung biopsy, intravenous catheter tips, and blood. Fungal growth on Sabouraud's dextrose agar produced a rapidly growing, wrinkled, cream-colored colony adherent to the agar with sparse white aerial mycelia. Microscopic examination with lactophenol cotton blue stain revealed wide, refractile, frequently septate hyphae. Further incubation and re-examination of the isolate revealed large, thick-walled primary and secondary chlamydoconidia, many of which had prominent papillae (Fig. 7). For further identification, the organism was referred to Dr. Donald Greer, Louisiana State University Medical Center, New Orleans, Louisiana. The fungus was subcultured on potato dextrose agar at room temperature. Examination of fungal colonies demonstrated short, white, aerial mycelia with conidiophores. The surface of the culture lid became covered with "conidia." Microscopic examination showed thick-walled spherical chlamydoconidia. Further microscopic analysis with lactophenol cotton blue stain demonstrated large unicellular sporangia that were forcibly expelled from short, unbranched sporangiophores. Most of the spores appeared as smooth, thickwalled conidia with protruding papillae. Villous projections were seen very rarely. Zygospores were not seen. Based on the prominent protruding papillae and occasional villous projections produced by the chlamydoconidia, the isolate was identified as Conidiobolus coronatus.
DISCUSSION Twenty-seven species of the genus Conidiobolus have been reported; three of these are authenticated vertebrate pathogens: C. coronatus, C. incongruous, and C. lamprauges.2 Most human infections are caused by C. coronatus, but a few cases caused by C. incongruous have been reported.3 These saprophytes have been isolated from soil and plant detritus throughout the world, including temperate regions.4 The first reported vertebrate infection due to a Conidiobolus sp. occurred in a horse in Texas in 1961. 56 Like other pathogenic fungi, these organisms cause a similar clinical illness in both humans and animals, manifested as granulomatous infection of the nasal mucosa. Animal infections, best documented in horses,7 also have been reported in chimpanzees.8 Human infection by Conidiobolus spp. usually takes the form of chronic rhinofacial zygomycosis, first reported
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FIG. 3 (upper). Left lung at autopsy contains a 7-cm cavitary infarct (arrow). Histologic sections of this area revealed abundant hyphae within abscesses, and vascular invasion.
iiobolus coronatus
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FIG. 6 (lower). Longitudinal and cross-sections of C. coronatus in the thyroid gland. Note broad, thin-walled, frequently septate hyphae and absence of eosinophilic Splendore-Hoeppli material (Grocott's methenamine silver stain, X40).
in 19659 and subsequently well described in patients from Nigeria by Martinson. 10 In addition to Africa, the disease has been reported in Central and South America, India, and East Asia.4 Cases of compatible clinical syndromes unconfirmed by culture also have been reported from North America."" 13 The disease manifests as an indolent
swelling of the nasal mucosa, especially the inferior turbinates, which may extend to submucosal structures with tumefaction and disfigurement. Although often localized, the infection also can progress to severe disfigurement and invasion of the paranasal sinuses,3 and spread to regional lymph nodes.14
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FIG. 5 (upper). Blood vessel wall invasion by C. coronatus hyphae in the cerebral cortex (Grocott's methenamine silver stain, X20).
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that this coating represents a "morphological manifestation of an antigen-antibody reaction between fungus and host."22 This histologic picture is not unique to these organisms but can occur as well in other fungal infections and also in parasitic infections.25 Notably lacking in most Entomophthorales infections are vascular invasion and thrombosis. 3 In our case, the morphologic findings are more compatible with mucormycosis than with infection by a member of the order Entomophthorales. SplendoreHoeppli eosinophilic sleeves were not identified around fungal hyphae, and vessel invasion was clearly seen in multiple organs. As noted by Symmers,22 the Mucorales cannot always FlG. 7. Chlamydoconidia of Conidiobolus coronalus have thick walls, be distinguished from the Entomophthorales by the lack prominent papillae, and no beaks. Rare villous appendages were seen of Splendore-Hoeppli syndrome and presence of vascular (potate dextrose agar, oil immersion). invasion in the former; rare cases of mucormycosis will manifest eosinophilic perihyphal sleeves, and vessel invasion has been reported in entomophthoramycosis. We Reports of infection in other anatomic locations are hypothesize that the absence of Splendore-Hoeppli synrare. There are a few reports of Conidiobolus spp. causing drome in the present case was due to the patient's inability a mediastinal mass in children, either alone or associated to mount and sustain an antibody response. Also, the with rhinofacial infection.I5~18 In one of these cases, C. patient's inability to fight the infection may have predisincongruus was confirmed as the etiologic agent.17 In one posed to the unusually aggressive behavior of the fungus case unconfirmed by culture, a mediastinal mass was in this case, that is, vessel invasion and dissemination. complicated by development of the superior vena cava syndrome.19 Of interest, histologic sections of the lung revealed evidence of infection with cytomegalovirus. This infection Our review of the literature found only two culturewas apparently localized to the lung. The extent to which proved cases of disseminated infection caused by Conithis infection contributed to the patient's death is undiobolus spp. A 1983 report documents a fatal infection known. It should be noted, however, that this patient had in a 20-year-old Thai woman that apparently began as a multiple opportunistic infections, and that cytomegalolocalized breast mass. She had no known immune defivirus infections in the transplant patient have been asciency. At autopsy, fungi were found in multiple organs sociated with coinfection by bacterial and fungal pathoand cultures grew C. incongruus.20 Recently, Jaffey and gens. colleagues21 reported a case of disseminated Conidiobolus infection in a 40-year-old drug addict in the United States. Our patient died of overwhelming infection with ConiFungal abscesses were found in many organs at autopsy. diobolus, despite receiving 1.2 g amphotericin B, treatFungi were found also in leg ulcers, which the authors ment intended for the patient's disseminated histoplaspropose were the portals of entry for the infection. The mosis. At autopsy no residual evidence of//, capsulatum authors suspected immunosuppression in this patient could be found by histologic examination or culture. In based on chronic cocaine abuse. The fungus in this case contrast, his Conidiobolus infection progressed while he could be identified only to the genus level, and therefore took amphotericin B. It should be noted that strains of it probably represents a previously unrecognized pathoC coronatus resistant to amphotericin B have been regenic Conidiobolus species.21 ported.26 Histologically, localized infections caused by both Treatment of localized Conidiobolus infections has been Conidiobolus and Basidiobolus are characterized by reviewed elsewhere.27 Some patients will clear such infecgranulomata, which may contain areas of focal necrosis tions spontaneously, whereas others have been cured by and fibrosis. Hyphae are usually abundant enough to be surgical therapy alone. Medically, potassium iodide traidentified readily. Suppuration is infrequent.22 Surroundditionally has been used, but successes also have been ing hyphal elements there is usually a prominent eosinreported with streptomycin, trimethoprim-sulfamethoxophilic sleeve, termed the Splendore-Hoeppli phenomeazole, amphotericin B, and ketoconazole.28,29 In vitro data 3 non. This represents a coating of the hyphae with a desuggest sensitivity to amphotericin B and imidazoles.26,27 position of protein, including host immunoglobulin, as However, experience with treatment of disseminated diswell as lipids and polysaccharides.2324 It has been suggested ease is limited.
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Acknowledgment. The authors thank Dr. Donald Greer for sharing his time, knowledge, and efforts to help identify the fungus.
REFERENCES 1. Rinaldi MG. Emerging Opportunists. Infect Dis Clin North Am 1989;3:65-76. 2. Goodman NL, Rinaldi MG. Agents of zygomycosis. In: Balows A, Hausler WJ Jr, Herrmann KL, Isenberg HD, Shadomy HJ, eds. Manual of Clinical Microbiology, Fifth Edition. Washington, D.C.: American Society for Microbiology, 1991, pp 675. 3. Rippon JW. Zygomycosis. In: Rippon JW, ed. Medical Mycology: The Pathogenic Fungi and the Pathogenic Actinomycetes, Third Edition. Philadelphia: WB Saunders, 1988, pp 681-713. 4. Clark BM. The epidemiology of entomophthoromycosis. In: AlDoory Y, ed. The Epidemiology of Human Mycotic Disease, First Edition. Springfield, IL: Charles C Thomas, 1975, pp 178— 196. 5. Emmons CW, Bridges CH. Entomophthora coronata, the etiologic agent of a phycomycosis of horses. Mycologia 1961;53:307-312. 6. Bridges CH, Romane WM, Emmons CW. Phycomycosis of horses caused by Entomophthora coronata. J Am Vet Med Assoc 1962;140:673-677. 7. Humber RA, Corrie CB, Kornegay RW. Equine zygomycosis caused by Conidiobolus lamprauges. J Clin Microbiol 1989;27:573-576. 8. Roy AD, Cameron HM. Rhinophycomycosis entomophthorae occurring in a chimpanzee in the wild in east Africa. Am J Trop MedHyg 1972;21:234-237. 9. Bras G, Gordon CC, Emmons CW, Prendegast KM, Sugar M. A case of Phycomycosis observed in Jamaica: Infection with Entomophthora coronata. Am J Trop Med Hyg 1965; 14:141-145.
10. Martinson FD, Clark BM. Rhinophycomycosis entomophthorae in Nigeria. Am J Trop Med Hyg 1967; 16:40-47. 11. Moretz ML, Grist WJ, Sewell CW. Zygomycosis presenting as nasal polyps in a healthy child. Arch Otolaryngol Head Neck Surg 1987;113:550-552. 12. Nathan MD, Keller AP, Lerner CJ, Davis JC. Entomophthorales infection of the maxillofacial region. Laryngoscope 1982;92:767769. 13. Singh J, Prasanna NM. Phycomycosis in an apparently normal host. J Otolaryngol 1977;6:37-42. 14. Kamalam A, Thambiah AS. Lymph node invasion by Conidiobolus coronatus and its spore formation in vivo. Sabauraudia 1978; 16: 175-184. 15. Gilbert EF, Khoury GH, Pore RS. Histopathological identification of Entomophthora phycomycosis. Arch Pathol 1970;90:583-587. 16. Eckert HL, Khoury GH, Pore RS, Gilbert EF, Gaskell JR. Deep Entomophthora phycomycotic infection reported for the first time in the United States. Chest 1972;61:392-394. 17. King DS, Jong SC. Identity of the etiological agent of the first deep entomophthoraceous infection of man in the United States. Mycologia 1976;68:181-183. 18. King JC, Dunphy D. Fatal phycomycosis without underlying disease. J Iowa Med Soc 1972; 112:485-488. 19. Marwaha K, Banerjee AK, Thapa BR, Agrawal SM. Mediastinal zygomycosis. Postgrad Med J 1985;61:733-735. 20. Busapakum R, Youngchaiyud U, Sriumpai S, Segretain G, Fromentin H. Disseminated infection with Conidiobolus incongruus. Sabouraudia 1983;21:323-330. 21. Jaffey PB, Haque AK, El-Zaatari M, Pasarell L, McGinnis MR. Disseminated Conidiobolus infection with endocarditis in a cocaine abuser. Arch Pathol Lab Med 1990; 114:1276-1278. 22. Symmers WS. Histopathology of phycomycoses. Ann Soc Belg Med Trop 1972;52:365-389. 23. Williams AO. Pathology of phycomycosis due to Entomophthora and Basidiobolus species. Arch Pathol 1969;87:13-20. 24. Bader G, Grueber HL. Histochemical studies of tissue forms and of perifungal substance in subcutaneous phycomycosis. Pathol Microbiol 1970;35:280-291. 25. Subramony C, Cason Z, O'Neal RM. Splendore-Hoeppli phenomenon around Blastomyces in cytologic preparation. Acta Cytol (Baltimore) 1984;28:684-686. 26. Yangco BG, Okafor JI, TeStrake D. In vitro susceptibilities of human and wild-type isolates of Basidiobolus and Conidiobolus species. Antimicrob Agents Chemother 1984;25:413-416; 1990; 114: 1276-1278. 27. Taylor GD, Sekhon AS, Tyrrell DL, Goldsand G. Rhinofacial zygomycosis caused by Conidiobolus coronatus: A case report including in vitro sensitivity to antimycotic agents. Am J Trop Med Hyg 1987;36:398-401. 28. Martinson FD. Clinical epidemiological and therapeutic aspects of entomophthoromycosis. Ann Soc Belg Med Trop 1972; 52:329342. 29. Towersey L, Wanke B, Estrella RR, et al. Conidiobolus coronatus infection treated with ketoconazole. Arch Dermatol 1988; 124: 1392-1396.
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This report documents what we believe to be the first case of disseminated infection with Conidiobolus coronatus reported in the English-language literature. In addition to the unusual clinical presentation, the pathologic findings were atypical compared with most previously reported infections. The Splendore-Hoeppli phenomenon was absent, and extensive vascular invasion was encountered, findings more typical of mucormycosis. In our case and in the case reported by Jaffey and colleagues,21 fungal abscesses found in multiple organs, first thought due to a mucoraceous zygomycete, were proved by culture to be caused by a Conidiobolus species. We offer this case as evidence that in such circumstances cultures are needed, rather than classification based on histologic features alone, to confirm the correct diagnosis. Whether differentiation will aid in the treatment of such infections remains to be determined.
Fatal Disseminated Conidiobolus coronatus Infection in a Renal Transplant Patient SUE D. WALKER, M.D., 1 RODERICK V. CLARK, M.D., 2 COLEMAN T. KING, M.D., 3 JOE E. HUMPHRIES, P H . D . , 1 LINDA S. LYTLE, M.T.(ASCP), 1 AND DONALD E. BUTKUS, M.D. 2
called the Splendore-Hoeppli phenomenon. The histologic findings in the present case were more typical of mucormycosis, and the correct diagnosis was established only after the organism was isolated and identified in culture. (Key words: Entomophthorales; Conidiobolus coronatus; Disseminated zygomycosis) Am J Clin Pathol 1992; 98:559-564
In recent years, opportunistic infections have become commonplace because there are more immunosuppressed patients who are susceptible to infection by a variety of microorganisms, including eukaryotes, prokaryotes, and viruses. Some of these organisms are known pathogens, whereas others are strict opportunists, and the infections they cause range from localized colonization to lethal dissemination. Of these organisms, the fungi have emerged as significant threats to persons with altered states of immunity. Although many of the fungal pathogens are well described, recent case reports have documented overwhelming infections caused by unusual fungi, such as dermatophytes, which were once thought to be relatively harmless. Disseminated infections caused by the genera Fusarium, Malassezia, Pseudallescheria, Scedosporium, and Trichosporon1 have now been reported. In addition, rare and exotic fungi, little known outside circles of professional mycologists, now sometimes produce clinical disease.
Recently we encountered a renal transplant patient with disseminated infection due to an unusual fungus, Conidiobolus coronatus, which typically causes localized nasal and soft-tissue infections in animals and humans, especially in tropical and subtropical regions. Our case was associated with simultaneous infection with two more conventional opportunists, Histoplasma capsulatum and cytomegalovirus. We describe this case and review other cases of human Conidiobolus infection reported in the literature. CASE REPORT
A 64-year-old man was transferred to our facility from an outlying hospital in July 1990 for evaluation of fever, pancytopenia, and pneumonia. The patient had a history of end-stage renal disease secondary to hypertension and had received a cadaveric renal transplant in 1983. He had been given maintenance drug therapy of imuran and prednisone, with creatinine values of 88 to 132 jumol/L. The patient's present symptoms began 3 months before admission, with anorexia, severe gingivitis, and a 35-pound weight loss. Shortly before he came to our hospital, he developed a low-grade fever and was treated with a 10-day course of oral antibiotics. The patient was admitted to his local hospital with streaky hemoptysis, From the University of Mississippi Medical Center, Departments of fever, chills, and pleuritic chest pain. He had a temperature of 40 °C, 2 'Pathology and Medicine. Divisions of Nephrology and ^Infectious Dis- gingival hyperplasia, and rales. Chest x-ray demonstrated bilateral lower eases, Jackson, Mississippi. lobe infiltrates. His white blood cell count was 1,300/mm3, with 21% segmented neutrophils, 53% banded neutrophils, 21% lymphocytes, \% Received November 8, 1991; revised manuscript accepted for publimonocytes, and 4% eosinophils. Hematocrit concentration was 45% and cation March 5, 1992. platelet count was 7,000/mm3. A gingival biopsy was performed and the Address correspondence to Dr. Sue Walker: Department of Pathology, patient was transferred to our center after 3 days of hospitalization for University of Mississippi Medical Center, 2500 North State Street, Jackfurther evaluation. son, Mississippi 39216.
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A case of fatal disseminated fungal infection due to Conidiobolus coronatus in a patient with a renal transplant is described. This organism, known to cause localized infections in otherwise healthy individuals in the tropics, is now recognized as a cause of fatal infection in immunosuppressed hosts. Histologically, localized infections are characterized by lack of vessel invasion and the presence of an eosinophilic sleeve around fungal elements,
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FIG. 1 (upper). Chest x-ray revealing a circumscribed pulmonary infiltrate that partially obscures the left lateral cardiac border. FIG. 2 (lower). Chest x-ray taken approximately 2 weeks after the chest x-ray shown in Figure 1. The expanded infiltrate in the left lung now contains a central lucency as a result of cavitation.
PATHOLOGIC FINDINGS At autopsy the inferior aspect of the upper lobe of the left lung contained a cavitary infarct measuring 7 X 5 X 5 cm (Fig. 3). The cavity contained necrotic tissue remnants and the surrounding lung tissue was firm and congested. The right lung contained several 1-cm rounded, tan lesions scattered throughout the parenchyma (Fig. 4). Cut sections of the myocardium revealed multiple red lesions measuring less than 2 mm that resembled petechiae. The right coronary artery was occluded just distal to its origin by recent thrombus. The renal allograft was enlarged and hydronephrotic, and cut sections revealed multiple hemorrhagic infarcts with abscess formation.
Coronal sections of the brain revealed multiple discrete lesions varying from 3 to 6 mm in both basal ganglia, and a 3-mm pale red lesion was found in the right upper red nucleus. The right posterior cerebellum contained a 3.5cm, dark, partially hemorrhagic infarct. Microscopic examination of multiple sections from all lung fields showed abscesses that contained abundant fragmented hyphae, which were visible with both hematoxylin and eosin and Gomori methenamine silver stains. The hyphal fragments were broad, frequently septate, and appeared hollow. The abscesses were composed primarily of neutrophils. The necrotic cavity in the left lung con-
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At physical examination, we noted that this elderly patient was frail and lethargic, although he responded appropriately. His body temperature was 37.8 °C. Examination of the chest revealed rales and wheezing. Results of an abdominal examination were normal and no peripheral adenopathy was noted. Symmetrical muscle wasting was observed in the lower extremities, but the neurologic examination was unremarkable. A chest x-ray showed bilateral lower lobe infiltrates. Pertinent laboratory values included a blood urea nitrogen level of 24.9 mmol/L and creatinine value of 309 ftmol/L. Arterial blood gases obtained on 2 L of oxygen via nasal canula were pH 7.50, Pco2 27 mmHg, and P02 51 mmHg. Review of the slides from the patient's gingival biopsy indicated a diagnosis of histoplasmosis, and antifungal therapy with amphotericin B was begun. Immunosuppressive therapy with imuran and prednisone was continued. A bone marrow aspirate and biopsy revealed a hypocellular marrow with negative fungal stains; however, cultures of this marrow grew Histoplasma capsulatum. On the fourth hospital day, the patient was afebrile and his appetite had returned. Amphotericin B was continued at a dose of 50 mg every other day, and he continued to improve subjectively as well as objectively: the chest x-ray and oxygenation improved; creatinine level decreased to 158.9 jimol/L, the white blood cell count increased to 11,000, and the platelet count increased to 54,000/mm3. Three weeks after admission, a Broviac catheter was placed to facilitate amphotericin B infusions in anticipation of outpatient therapy. Two days after this procedure, the patient's body temperature increased to 38.3 °C, his blood pressure decreased to 90/60 mmHg, and dyspnea developed. Repeated chestfilmsrevealed a new left lower lobe infiltrate (Fig. 1), and arterial blood gases measured on room air were pH 7.51, PCOJ 55 mmHg and P02 50 mmHg. Intravenous mezlocillin and gentamicin were given, and amphotericin B was continued. A fever of 39 °C persisted while the patient was taking this drug regimen, and after 3 days vancomycin was added. Fiberoptic bronchoscopy was performed and cytologic examination of bronchial washings revealed hemosiderin-laden macrophages andfilamentssuggesting an Aspergillus sp. Gram's stain and acid-fast smears were negative. Bacterial and fungal cultures of fiberoptic bronchoscopy washings were negative as well. The patient's respiratory status continued to decline, with worsening hypoxemia and progressive pulmonary infiltrates evident on chest x-ray. Five weeks after admission, acute respiratory distress developed that required intubation and mechanical ventilation. Although he was stabilized initially, anasarca and hypotension developed and urine output decreased. Repeated fiberoptic bronchoscopy washings revealedfilamentousorganisms resembling a zygomycete. Chest x-ray revealed a lucency within the left lung infiltrate (Fig. 2). Diagnostic open lung biopsy was in progress when cardiopulmonary arrest occurred and the patient died. An autopsy was performed.
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„|llil|iill|llll|illl|llll|llll|illl|lllijllii|iiilHIII|iiiH
FIG. 4 (lower). Right lung shows multiple 1-cm tan nodules (arrows). Microscopically these areas contained cells with intranuclear inclusions characteristic of cytomegalovirus infection. Hyphae were not found in these lesions.
tained inflammatory cell debris and many fungal elements. Examination of the adjacent parenchyma revealed fungal hyphae within alveolar spaces, with invasion of pulmonary vessel walls. Cells with intracytoplasmic and Cowdry type A intranuclear inclusions compatible with cytomegalovirus infection were seen in slides from the small nodules in the right lung, but hyphae were not found in these lesions. Microabscesses containing angioinvasive fungal elements, similar to those in the lungs, also were found in the right coronary artery thrombus, myocardium, brain, renal allograft, and thyroid. Of interest, the fungal hyphae were not enveloped by Splendore-Hoeppli material (Figs. 5 and 6). MICROBIOLOGIC METHODS AND FINDINGS All specimens obtained at surgery and autopsy were cultured on Sabouraud's dextrose agar with and without
chloramphenicol, mycosel agar, and trypticase soy agar with 5% sheep blood, chocolate, and MaConkey agar. After 2 days at room temperature, fungal growth on Trypticase soy agar with 5% sheep blood occurred in the culture of bronchial washings. Subsequently, identical growth occurred in both routine and fungal media from the following specimens: pleural fluid, lung biopsy, intravenous catheter tips, and blood. Fungal growth on Sabouraud's dextrose agar produced a rapidly growing, wrinkled, cream-colored colony adherent to the agar with sparse white aerial mycelia. Microscopic examination with lactophenol cotton blue stain revealed wide, refractile, frequently septate hyphae. Further incubation and re-examination of the isolate revealed large, thick-walled primary and secondary chlamydoconidia, many of which had prominent papillae (Fig. 7). For further identification, the organism was referred to Dr. Donald Greer, Louisiana State University Medical Center, New Orleans, Louisiana. The fungus was subcultured on potato dextrose agar at room temperature. Examination of fungal colonies demonstrated short, white, aerial mycelia with conidiophores. The surface of the culture lid became covered with "conidia." Microscopic examination showed thick-walled spherical chlamydoconidia. Further microscopic analysis with lactophenol cotton blue stain demonstrated large unicellular sporangia that were forcibly expelled from short, unbranched sporangiophores. Most of the spores appeared as smooth, thickwalled conidia with protruding papillae. Villous projections were seen very rarely. Zygospores were not seen. Based on the prominent protruding papillae and occasional villous projections produced by the chlamydoconidia, the isolate was identified as Conidiobolus coronatus.
DISCUSSION Twenty-seven species of the genus Conidiobolus have been reported; three of these are authenticated vertebrate pathogens: C. coronatus, C. incongruous, and C. lamprauges.2 Most human infections are caused by C. coronatus, but a few cases caused by C. incongruous have been reported.3 These saprophytes have been isolated from soil and plant detritus throughout the world, including temperate regions.4 The first reported vertebrate infection due to a Conidiobolus sp. occurred in a horse in Texas in 1961. 56 Like other pathogenic fungi, these organisms cause a similar clinical illness in both humans and animals, manifested as granulomatous infection of the nasal mucosa. Animal infections, best documented in horses,7 also have been reported in chimpanzees.8 Human infection by Conidiobolus spp. usually takes the form of chronic rhinofacial zygomycosis, first reported
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FIG. 3 (upper). Left lung at autopsy contains a 7-cm cavitary infarct (arrow). Histologic sections of this area revealed abundant hyphae within abscesses, and vascular invasion.
iiobolus coronatus
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FIG. 6 (lower). Longitudinal and cross-sections of C. coronatus in the thyroid gland. Note broad, thin-walled, frequently septate hyphae and absence of eosinophilic Splendore-Hoeppli material (Grocott's methenamine silver stain, X40).
in 19659 and subsequently well described in patients from Nigeria by Martinson. 10 In addition to Africa, the disease has been reported in Central and South America, India, and East Asia.4 Cases of compatible clinical syndromes unconfirmed by culture also have been reported from North America."" 13 The disease manifests as an indolent
swelling of the nasal mucosa, especially the inferior turbinates, which may extend to submucosal structures with tumefaction and disfigurement. Although often localized, the infection also can progress to severe disfigurement and invasion of the paranasal sinuses,3 and spread to regional lymph nodes.14
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FIG. 5 (upper). Blood vessel wall invasion by C. coronatus hyphae in the cerebral cortex (Grocott's methenamine silver stain, X20).
WALKER ET AL.
Fatal Disseminated
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idiobolus coronatus
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that this coating represents a "morphological manifestation of an antigen-antibody reaction between fungus and host."22 This histologic picture is not unique to these organisms but can occur as well in other fungal infections and also in parasitic infections.25 Notably lacking in most Entomophthorales infections are vascular invasion and thrombosis. 3 In our case, the morphologic findings are more compatible with mucormycosis than with infection by a member of the order Entomophthorales. SplendoreHoeppli eosinophilic sleeves were not identified around fungal hyphae, and vessel invasion was clearly seen in multiple organs. As noted by Symmers,22 the Mucorales cannot always FlG. 7. Chlamydoconidia of Conidiobolus coronalus have thick walls, be distinguished from the Entomophthorales by the lack prominent papillae, and no beaks. Rare villous appendages were seen of Splendore-Hoeppli syndrome and presence of vascular (potate dextrose agar, oil immersion). invasion in the former; rare cases of mucormycosis will manifest eosinophilic perihyphal sleeves, and vessel invasion has been reported in entomophthoramycosis. We Reports of infection in other anatomic locations are hypothesize that the absence of Splendore-Hoeppli synrare. There are a few reports of Conidiobolus spp. causing drome in the present case was due to the patient's inability a mediastinal mass in children, either alone or associated to mount and sustain an antibody response. Also, the with rhinofacial infection.I5~18 In one of these cases, C. patient's inability to fight the infection may have predisincongruus was confirmed as the etiologic agent.17 In one posed to the unusually aggressive behavior of the fungus case unconfirmed by culture, a mediastinal mass was in this case, that is, vessel invasion and dissemination. complicated by development of the superior vena cava syndrome.19 Of interest, histologic sections of the lung revealed evidence of infection with cytomegalovirus. This infection Our review of the literature found only two culturewas apparently localized to the lung. The extent to which proved cases of disseminated infection caused by Conithis infection contributed to the patient's death is undiobolus spp. A 1983 report documents a fatal infection known. It should be noted, however, that this patient had in a 20-year-old Thai woman that apparently began as a multiple opportunistic infections, and that cytomegalolocalized breast mass. She had no known immune defivirus infections in the transplant patient have been asciency. At autopsy, fungi were found in multiple organs sociated with coinfection by bacterial and fungal pathoand cultures grew C. incongruus.20 Recently, Jaffey and gens. colleagues21 reported a case of disseminated Conidiobolus infection in a 40-year-old drug addict in the United States. Our patient died of overwhelming infection with ConiFungal abscesses were found in many organs at autopsy. diobolus, despite receiving 1.2 g amphotericin B, treatFungi were found also in leg ulcers, which the authors ment intended for the patient's disseminated histoplaspropose were the portals of entry for the infection. The mosis. At autopsy no residual evidence of//, capsulatum authors suspected immunosuppression in this patient could be found by histologic examination or culture. In based on chronic cocaine abuse. The fungus in this case contrast, his Conidiobolus infection progressed while he could be identified only to the genus level, and therefore took amphotericin B. It should be noted that strains of it probably represents a previously unrecognized pathoC coronatus resistant to amphotericin B have been regenic Conidiobolus species.21 ported.26 Histologically, localized infections caused by both Treatment of localized Conidiobolus infections has been Conidiobolus and Basidiobolus are characterized by reviewed elsewhere.27 Some patients will clear such infecgranulomata, which may contain areas of focal necrosis tions spontaneously, whereas others have been cured by and fibrosis. Hyphae are usually abundant enough to be surgical therapy alone. Medically, potassium iodide traidentified readily. Suppuration is infrequent.22 Surroundditionally has been used, but successes also have been ing hyphal elements there is usually a prominent eosinreported with streptomycin, trimethoprim-sulfamethoxophilic sleeve, termed the Splendore-Hoeppli phenomeazole, amphotericin B, and ketoconazole.28,29 In vitro data 3 non. This represents a coating of the hyphae with a desuggest sensitivity to amphotericin B and imidazoles.26,27 position of protein, including host immunoglobulin, as However, experience with treatment of disseminated diswell as lipids and polysaccharides.2324 It has been suggested ease is limited.
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Acknowledgment. The authors thank Dr. Donald Greer for sharing his time, knowledge, and efforts to help identify the fungus.
REFERENCES 1. Rinaldi MG. Emerging Opportunists. Infect Dis Clin North Am 1989;3:65-76. 2. Goodman NL, Rinaldi MG. Agents of zygomycosis. In: Balows A, Hausler WJ Jr, Herrmann KL, Isenberg HD, Shadomy HJ, eds. Manual of Clinical Microbiology, Fifth Edition. Washington, D.C.: American Society for Microbiology, 1991, pp 675. 3. Rippon JW. Zygomycosis. In: Rippon JW, ed. Medical Mycology: The Pathogenic Fungi and the Pathogenic Actinomycetes, Third Edition. Philadelphia: WB Saunders, 1988, pp 681-713. 4. Clark BM. The epidemiology of entomophthoromycosis. In: AlDoory Y, ed. The Epidemiology of Human Mycotic Disease, First Edition. Springfield, IL: Charles C Thomas, 1975, pp 178— 196. 5. Emmons CW, Bridges CH. Entomophthora coronata, the etiologic agent of a phycomycosis of horses. Mycologia 1961;53:307-312. 6. Bridges CH, Romane WM, Emmons CW. Phycomycosis of horses caused by Entomophthora coronata. J Am Vet Med Assoc 1962;140:673-677. 7. Humber RA, Corrie CB, Kornegay RW. Equine zygomycosis caused by Conidiobolus lamprauges. J Clin Microbiol 1989;27:573-576. 8. Roy AD, Cameron HM. Rhinophycomycosis entomophthorae occurring in a chimpanzee in the wild in east Africa. Am J Trop MedHyg 1972;21:234-237. 9. Bras G, Gordon CC, Emmons CW, Prendegast KM, Sugar M. A case of Phycomycosis observed in Jamaica: Infection with Entomophthora coronata. Am J Trop Med Hyg 1965; 14:141-145.
10. Martinson FD, Clark BM. Rhinophycomycosis entomophthorae in Nigeria. Am J Trop Med Hyg 1967; 16:40-47. 11. Moretz ML, Grist WJ, Sewell CW. Zygomycosis presenting as nasal polyps in a healthy child. Arch Otolaryngol Head Neck Surg 1987;113:550-552. 12. Nathan MD, Keller AP, Lerner CJ, Davis JC. Entomophthorales infection of the maxillofacial region. Laryngoscope 1982;92:767769. 13. Singh J, Prasanna NM. Phycomycosis in an apparently normal host. J Otolaryngol 1977;6:37-42. 14. Kamalam A, Thambiah AS. Lymph node invasion by Conidiobolus coronatus and its spore formation in vivo. Sabauraudia 1978; 16: 175-184. 15. Gilbert EF, Khoury GH, Pore RS. Histopathological identification of Entomophthora phycomycosis. Arch Pathol 1970;90:583-587. 16. Eckert HL, Khoury GH, Pore RS, Gilbert EF, Gaskell JR. Deep Entomophthora phycomycotic infection reported for the first time in the United States. Chest 1972;61:392-394. 17. King DS, Jong SC. Identity of the etiological agent of the first deep entomophthoraceous infection of man in the United States. Mycologia 1976;68:181-183. 18. King JC, Dunphy D. Fatal phycomycosis without underlying disease. J Iowa Med Soc 1972; 112:485-488. 19. Marwaha K, Banerjee AK, Thapa BR, Agrawal SM. Mediastinal zygomycosis. Postgrad Med J 1985;61:733-735. 20. Busapakum R, Youngchaiyud U, Sriumpai S, Segretain G, Fromentin H. Disseminated infection with Conidiobolus incongruus. Sabouraudia 1983;21:323-330. 21. Jaffey PB, Haque AK, El-Zaatari M, Pasarell L, McGinnis MR. Disseminated Conidiobolus infection with endocarditis in a cocaine abuser. Arch Pathol Lab Med 1990; 114:1276-1278. 22. Symmers WS. Histopathology of phycomycoses. Ann Soc Belg Med Trop 1972;52:365-389. 23. Williams AO. Pathology of phycomycosis due to Entomophthora and Basidiobolus species. Arch Pathol 1969;87:13-20. 24. Bader G, Grueber HL. Histochemical studies of tissue forms and of perifungal substance in subcutaneous phycomycosis. Pathol Microbiol 1970;35:280-291. 25. Subramony C, Cason Z, O'Neal RM. Splendore-Hoeppli phenomenon around Blastomyces in cytologic preparation. Acta Cytol (Baltimore) 1984;28:684-686. 26. Yangco BG, Okafor JI, TeStrake D. In vitro susceptibilities of human and wild-type isolates of Basidiobolus and Conidiobolus species. Antimicrob Agents Chemother 1984;25:413-416; 1990; 114: 1276-1278. 27. Taylor GD, Sekhon AS, Tyrrell DL, Goldsand G. Rhinofacial zygomycosis caused by Conidiobolus coronatus: A case report including in vitro sensitivity to antimycotic agents. Am J Trop Med Hyg 1987;36:398-401. 28. Martinson FD. Clinical epidemiological and therapeutic aspects of entomophthoromycosis. Ann Soc Belg Med Trop 1972; 52:329342. 29. Towersey L, Wanke B, Estrella RR, et al. Conidiobolus coronatus infection treated with ketoconazole. Arch Dermatol 1988; 124: 1392-1396.
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This report documents what we believe to be the first case of disseminated infection with Conidiobolus coronatus reported in the English-language literature. In addition to the unusual clinical presentation, the pathologic findings were atypical compared with most previously reported infections. The Splendore-Hoeppli phenomenon was absent, and extensive vascular invasion was encountered, findings more typical of mucormycosis. In our case and in the case reported by Jaffey and colleagues,21 fungal abscesses found in multiple organs, first thought due to a mucoraceous zygomycete, were proved by culture to be caused by a Conidiobolus species. We offer this case as evidence that in such circumstances cultures are needed, rather than classification based on histologic features alone, to confirm the correct diagnosis. Whether differentiation will aid in the treatment of such infections remains to be determined.
