Diagnostic Radiology
Atypi(al Radiographi( Features in Pneumocyst;s carin;; Pneumonia l John L Doppman, M.D., Glenn W. Geelhoed, M.D.,2 and Vincent T. De Vita, M.D. The chcst films in 30 proved cases of Pneumocysiis carinii pneumonia were reviewed to determine the incidence of atypical radiographic findings. Seventeen of ;30 patients or 56% presented at least one atypical radiographic finding during the course of the disease. Unilateral distribution, lobar involvement, abscess formation, fulminant progression, and atelectatic changes were observed in more than half the patients. A classic radiographic presentation, justifying treatment without biopsy, was seen in only 13 of the 30 patients. INDEX TERMS:
Lungs, cavitation • Lungs, collapse. Pneumonia
Radiology 114:39-44, January 1975
• characteristic radiographic findings in pneumonia have been well described and need no repetition (1-10, 1316). Our purpose in undertaking this review was to attempt to answer two questions frequently raised by clinicians caring for immunosuppressed patients with acute pulmonary symptoms. (a) Is the chest film in Pneumocystis pneumonia sufficiently characteristic to justify the institution of pentamidine therapy without obtaining histologic confirmation? (b) Are certain radiographic features such as asymmetric distribution, pleural fluid or cavitation
T Pneumocystis carinii HE
sufficiently rare in Pneumocystis pneumonia to justify excluding this diagnosis without a biopsy? MATERIAL
We have reviewed the clinical, pathologic and radiographic findings in a series of 30 patients with proved Pneumocystis carinii pneumonia. In 14 of these patients, the organism was demonstrated by lung biopsy (11) and in Hi, Pneumocystis was identified in lungs examined at autopsy. These patients typically presented the clinical findings of fever, nonproductive cough and progressive dyspnea with minimal auscultatory findings.
A Fig. 1. A. Typical Pncuniocystis carinii pneumonia. Note relative sparing, oj apices as well as absence of adenopathy or pleural changes. B. Central or perihilar distribution in Pn cumocyst is pneumonia. Note also the slight pseudonodular pattern. 1 From the Department of Diagnostic Radiology 0. L. D.), Surgery Branch (G. W. G.), Medicine Branch (V. T. D. \'.), National Institutes of Health, Bethesda, MlL Accepted for publication in August 1974. 2 Present address: Department of Surgery, George Washington University Hospital. \Vashington, D. C. 20037. shan
J. L.
40
Fig. 2.
DOPPMAN, G.
W.
GEELHOED AND V.
Extensive air bronchograrns are seen, especially in the upper lobes.
The majority of them had a lymphoreticular malignancy (either leukemia or lymphoma). In more than half, the underlying malignancy was in remission when the pneumonia developed (.9). A few had primary immunodeficiency diseases. All patients were receiving treatment consisting of either combined chemotherapy, corticosteroid therapy, or wide-spectrum antibiotic therapy. TYPICAL RADIOGRAPHIC FEATURES
The classic radiographic findings of Pneumocystis carinii pneumonia are illustrated in Figure 1. A diffuse bilateral infiltrate is usually seen, perihilar in distribution and radiating out into both lung fields (Fig. 1, A). The apices of the lungs are frequently not involved and apical sparing has been described as a typical radiographic finding, Less commonly seen is relative sparing of the apices and bases with the infiltrate presenting as a truly cen-
Fig.
a.
A and B.
T.
DE VITA
January 1975
tral or perihilar process (Fig. 1, B). Generally, pleural effusion is not seen nor is hilar adenopathy present. The infiltrate is initially a patchy reticulogranular process progressing to a more diffuse alveolar consolidation. Although classically described as an "interstitial pneumonia," acute Pneumocystis pneumonia, as seen in immunosuppressed adults, is predominantly an alveolar or air-space consolidation with a variable but minor interstitial component of lymphoplasmocytic infiltrate. Early acinar involvement is patchy and may be confused with interstitial disease on the chest film but rapid progression leading to coalescence and air bronchograms makes its predominantly alveolar nature evident. Extensive air bronchograms are common and were seen in If) of our 30 cases (53%) (Fig. 2). Forrest (8) and Bragg and Janis (2) have recently commented upon the inaccuracy of referring to Pneumocystis carinii pneumonia as a predominantly interstitial process. Pneumocystis carinii pneumonia is typically an acute inflammatory process and generally progresses from patchy alveolar infiltrate to widespread consolidation in 3-5 days. Of 14 proved fatal cases, 9 were dead within 5 days and 13 within 10 days from onset. The last fatality occurred at 14 days. Successful treatment results in clinical improvement within 48-96 hours but the radiographic findings take longer to resolve. In 16 histologically proved and successfully treated patients, 10 showed complete radiographic clearing within 10 days but (j patients took up to 30 days for complete resolution. Persistent interstitial fibrosis
Note predominant right (A) and left-sided involvement (B) in these 2 proved cases of Pneumocystis carinii pneumonia.
Vo!. 114
ATYPICAL RADIOGRAPHIC FEATURES IN
Pneumocystis carinii
PNEUMONIA
41
Diagnostic Radiology
has been reported (17) following treated Pneumacystis carinii pneumonia but was not observed in our senes. In summary, classic Pneumocystis carinii pneumonia is an acute bilateral perihilar and basilar infiltrate progressing to diffuse alveolar consolidation within 3-4 days and unassociated with adenopathy or pleural changes. In the appropriate clinical setting, this typical radiographic picture is practically diagnostic. However, the incidence of atypical radiographic findings has not been extensively investigated and we therefore reviewed our cases to determine their frequency. ATYPICAL RADIOGRAPHIC FINDINGS
Distribution: Sparing of the apices of the lung was observed in 18 patients but 12 patients or 40% failed to show this pattern on any of the available films. Although 26 of our patients exhibited typical bilateral distribution, 4 individuals or 13% displayed marked unilateral predominance of the Pneumocystis infiltrate (Fig. 3). In no instance, however, was the contralateral lung completely free of disease. In addition, 2 patients (7%) exhibited lobar or segmental consolidation in addition to diffuse involvement (Fig. 4). Although a number of our patients had received mediastinal irradiation, sparing of the paramediastinal irradiated lung, as recently described by Forrest (8), was never observed. However, one patient who had radiotherapy to the left upper
A
Fig. 4.
Diffuse bilateral infiltrates are present in addition to a localized right middle-lobe consolidation.
thorax for breast carcinoma demonstrated sparing of the irradiated left upper lobe when Pneumocystis pneumonia developed during chemotherapy (Fig. .5). Type oj Infiltrate: Two cases of confirmed Pneumocystis pneumonia exhibited a pseudonodular pattern giving rise to some confusion with metastatic processes. Such a pseudonodular pattern has been observed by others (2,18). In addition, 2 patients demonstrated areas of linear atelectasis early in the course of their disease (Fig. 6). In both instances, diaphragms were high and this may have represented a hypoventilatory phenome-
8
Fig. 5. A. Control chest film shows absent left breast, but no evidence of radiation changes in the left upper lobe. left pleural effusion. B. Pneumocysiis infiltrate spares the irradiated left upper lung.
Note malignant
J. L.
42
Fig. 6.
DOPPMAN, G.
W.
GEELHOED AND V.
T.
DE VITA
January 1975
Bilaterallo~er
lobe linear shadows (arrows) in early pneumoma, probably atelectatic changes. Xote incidental right aortic arch. !Jn~umocyslls
non. The atelectasis disappeared as the infiltrate progressed. A single patient demonstrated breakdown in a focal area of consolidation in the left lower lobe. (Fig. 7). At autopsy, widespread Pneumocystis pneumonia with cavitation and acute necrosis was seen. Pneumocystis carinii organisms were present in abundance in the wall of the left lower lobe abscess but Monilia was also cultured from the lung, Pleural Findings: Absence of pleural fluid has been proposed as so characteristic a finding in Pneumocystis pneumonia that a small effusion according to most authors, practically excludes the diagnosis. Forrest (8) recently reported bilateral pleural effusions in 2 of 12 proved cases (17%). One of these patients, however, had a collagenvasc~lar dise~se. Prior to his report, only one previous effusion had been described (11) and in this case, associated heart failure was present. ' In our 3D proved cases, after effusions antedating the p'neumocystis pneumonia or following percutaneous biopsy were carefully excluded, the possibility of small pleural effusions was suggested in () cases or 20%. Portable decubitus films were taken in several patients in an attempt to confirm the p:esencc of sr:rall effusions but were usually technically unsatisfactory in these sick individuals. No thoracenteses were performed. Two of the 6
TABLE
I:
PLEURAL FLUID IN 18 AUTOPSIED PATIENTS' WITH Pneumocysiis PNEUMONIA
None
Less than 50 ml *
More than 75 ml
14 (78%)
2 (11%)
2t (11 %)
16 89%
* Probably undetectable on portable chest films.
t
One had Monilia in addition to Pneumocysiis.
Fig. 7.
Central excavation (arrows) suggests abscess formation.
patients in whom fluid was suspected died; at the pleural spaces were dry. Peripheral mfiltrate can obscure the costophrenic angle and suggest a small pleural effusion. We suspect that 5 o.f. our 6 pleural fluid diagnoses were falsely posrtive buthave proved it in only 2. In order to more fully evaluate the incidence of pleural fluid in Pneumocystis carinii pneumonia, autopsy protocols were reviewed in 18 fatal cases. The presence or absence of pleural fluid was invariably recorded by the prosector. The results are presented in TABLE 1. Fourteen cases, or 78% had dry pleural spaces. Less than 50 ml, probably undetectable on portable chest films, was present in 2 patients and 2 others had larger effusions of 100 and 125 ml. Only one of these was diagnosed roentgenographically and this patient also had a superimposed monilial infection. Certainly, pleural fluid in roentgenographically detectable quantitie's is very rare in uncomplicated Pneumocystis carinii pneumonia. Pneumothoraces, apart from biopsy attempts, were observed in 2 children with Pneumocystis carinii pneumonia. This complication is common in interstitial or plasma cell pneumonia of newborns (3, 4). Robillard et al. (14) reported 5 instances of pneumomediastinum or pneumothorax in 22 infants and all children with this complication ~utopsy,
Va!. 114
ATYPICAL RADIOGRAPHIC FEATURES IN
Pneumocystis carinii
PNEUMONIA
43
Diagnostic Radiology
B
A Fig. 8.
A and B.
Initial chest film (A) and extensive Pneumocystis infiltration 12 hours later (B).
died. Spontaneous pneumothorax was never observed in our adult patients. Hilar prominence suggesting adenopathy was observed in 2 patients. Histologic confirmation was not obtained. In view of the perihilar distribution of the infiltrate, minor degrees of adenopathy could easily go undetected. In addition, hilar adenopathy is a prominent feature of the lymphoreticular diseases so common in this series. A review of autopsy findings in 18 fatal cases revealed hilar or mediastinal adenopathy in 6 patients (33%). However, in every case, the' enlarged nodes were due to the underlying myeloproliferative disorder or non-pneumocystic inflammatory process (2 leukemia; 2 lymphoma; 1 tuberculous infection complicating lupus; and 1 Wiskott-Aldrich syndrome with reticuloendothelial tumor). Progression: Progression of the radiographic findings in Pneumocystis carinii pneumonia from a patchy infiltrate to diffuse consolidation generally occurs over 3-5 days. In 2 cases, one adult and one child, massive consolidation developed within 12 hours (Fig. 8), suggesting some alternate diagnosis such as pulmonary edema or hemorrhage. In several successfully treated patients, clearing was delayed up to six weeks but in no instance were chronic interstitial changes observed in survivors. DISCUSSION
The classic radiographic appearance in the appropriate clinical setting probably justifies a presumptive diagnosis of Pneumocystis carinii pneumonia and the initiation of therapy without histologic confirmation. Although violating basic
bacteriologic principles, such a course of action is justified because percutaneous or open lung biopsy in these dyspneic, often thrombocytopenic patients, is associated with a significant morbidity. Unfortunately, at least half of our 30 proved cases had one or more atypical radiographic findings and, in this group, bacteriologic confirmation by brushing, needle aspiration or biopsy is indicated. All of the atypical radiographic findings that we have illustrated have been previously described. Pneumothorax and pneumomediastinum have been stressed in the pediatric literature (3, 4, (5, 14). Several authors have mentioned instances of asymmetrical distribution (2, 8), lobar consolidation (2,8), pseudonodular infiltrate (2, 18), and pleural effusions (2, 8, 11). From our review, it is apparent that the incidence of atypical radiographic findings is appreciable, 17 of our 30 proved cases or 56% demonstrating at least one such finding. Therefore, histological confirmation will probably be necessary in a significant percentage of cases. If bronchial brushing proves to be as effective as preliminary reports suggest (12), it will undoubedly become the biopsy procedure of choice. Equally distressing is the conclusion from this study that few radiographic findings completely exclude the diagnosis of Pneumocystis. Large pleural effusions and prominent hilar adenopathy probably do. But lobar involvement, unilateral predominance, fulminant progression, tissue breakdown, atelectatic changes and a pseudonodular pattern have been seen in histologically proved Pneumocystis pneumonia. In an immunosuppressed patient, therefore, biopsy may be indicated in the absence of a classic radiographic presentation.
44
J. L.
DOPPMAN, G.
W.
GEELHOED AND V.
REFERENCES 1. Bradshaw M, Myerowitz RL, Schneerson R, et al: Pneurnocystis carinii pneumonitis. Ann Intern Med 73: 775-777. AOV 1970 2. Bragg DG, J anis B: The roentgenographic manifestations of pulmonary opportunistic infections. Am J Roentgenol 117: 798-809, Apr 1973 3. Capitanio MA, Kirkpatrick J A Jr: Pneumocystis carinii pneumonia. Am J Roentgenol 97:174-180, May 1966 4. Cohen WN, McAllister WH: Pneumocystis carinii pneumonia. Report of four cases. Am J Roentgenol 89: 1032-1037, May 1963 5. Ebel KD, Fendel H: The roentgen changes of pneumocystis pneumonia and their anatornic basis. [In] Progress in Pediatric Radiology, Kaufmann H], ed. S Karger, Basel/New York, Vol I, 1967 6. Falkenbach KH, Bachmann KD, O'Loughlin BJ: Pneumocystis carinii pneumonia. Am J Roentgenol85: 706-713, April 1961 7. Feinberg SB, Lester RG, Burke BA: The roentgen findings in pneumocyst.is carinii pneumonia. Radiology 76: 594-599, ApT 1961 8. Forrr st JV: Radiological findings in pneurnocyst is carinii pneumonia. Radiology 103:539-544, j un 1972 9. Geelhoed GW, Powell RD Jr, Doppman JL, et al : Pneumocystis c~rinii pneumonia in cancer patients following ~mml;'nosuppresslve chemotherapy: results of pentamidine isothionat e treatment. Presented at the American Thoracic Society Meeting in New York, May 20-23, 1973 10. Goodell B, Jacobs JB, Powell RD jr, et al: Pneumocystis carinii; the spectrum of diffuse interstitial pneumonia in pa-
T.
DE VITA
January
1975
tients with neoplastic diseases. Ann Intern Med 72 :337-340, Mar 1970 . 11. Jambs J.B, Vogel C, Powell RD Jr, et al: Needle biopsy 111 pneumocystis carmn pneumonia. Radiology 93: 525-530 Sep 1969 ' 12. Reps.her ~~" Schroter .G., Hammon WS: Diagnosis of pneumocystis carmu pneumorutis by means of endobronchial brush biopsy. N Engl J Med 287:340-341,17 Aug 1972 13. Rifkind D, Faris TD, Hill RB Jr: Pneumocystis carinii pneumonia. Studies on the diagnosis and treatment. Ann Intern Med. 65: 943-956, Nov 1966 14. Robillard G, Bertrand R, Gn§goire H, et al: Plasma cell pneumonia in infants. Review of 51 cases. J Canad Assoc Radiol 16: 161-168, Sep 196,5 1.5.. Thomas. SF, Dutz W, Khodadad EJ: Pneumocystis carrnn pneumonia (plasma cell pneumonia). Am J Roentgenol 98:318-322, Oct Hl66 1.6... Vogel C~, Cohen MH, Powel! RD Jr, et al: Pneumocystis carmu pneumonia. Ann Intern Med 68:97-108, Jan 1968 17. Whitcomb ME, Schwarz MI Charles MA et al: Interstitial fibrosis after pneumocystis' carinii pne~monia. Ann Intern Med 73: 761-765, Nov 1970 18: Cross ;\S, Steigbigel RT: Pneumocystis carinii pneumorua presenting as localized nodular densities. N Engl .I Med 291:831-832,17 Oct 1974 .
Department of Diagnostic Radiology Building 10, Room 6S211 National Institutes of Health Bethesda, Md. 20014
Atypi(al Radiographi( Features in Pneumocyst;s carin;; Pneumonia l John L Doppman, M.D., Glenn W. Geelhoed, M.D.,2 and Vincent T. De Vita, M.D. The chcst films in 30 proved cases of Pneumocysiis carinii pneumonia were reviewed to determine the incidence of atypical radiographic findings. Seventeen of ;30 patients or 56% presented at least one atypical radiographic finding during the course of the disease. Unilateral distribution, lobar involvement, abscess formation, fulminant progression, and atelectatic changes were observed in more than half the patients. A classic radiographic presentation, justifying treatment without biopsy, was seen in only 13 of the 30 patients. INDEX TERMS:
Lungs, cavitation • Lungs, collapse. Pneumonia
Radiology 114:39-44, January 1975
• characteristic radiographic findings in pneumonia have been well described and need no repetition (1-10, 1316). Our purpose in undertaking this review was to attempt to answer two questions frequently raised by clinicians caring for immunosuppressed patients with acute pulmonary symptoms. (a) Is the chest film in Pneumocystis pneumonia sufficiently characteristic to justify the institution of pentamidine therapy without obtaining histologic confirmation? (b) Are certain radiographic features such as asymmetric distribution, pleural fluid or cavitation
T Pneumocystis carinii HE
sufficiently rare in Pneumocystis pneumonia to justify excluding this diagnosis without a biopsy? MATERIAL
We have reviewed the clinical, pathologic and radiographic findings in a series of 30 patients with proved Pneumocystis carinii pneumonia. In 14 of these patients, the organism was demonstrated by lung biopsy (11) and in Hi, Pneumocystis was identified in lungs examined at autopsy. These patients typically presented the clinical findings of fever, nonproductive cough and progressive dyspnea with minimal auscultatory findings.
A Fig. 1. A. Typical Pncuniocystis carinii pneumonia. Note relative sparing, oj apices as well as absence of adenopathy or pleural changes. B. Central or perihilar distribution in Pn cumocyst is pneumonia. Note also the slight pseudonodular pattern. 1 From the Department of Diagnostic Radiology 0. L. D.), Surgery Branch (G. W. G.), Medicine Branch (V. T. D. \'.), National Institutes of Health, Bethesda, MlL Accepted for publication in August 1974. 2 Present address: Department of Surgery, George Washington University Hospital. \Vashington, D. C. 20037. shan
J. L.
40
Fig. 2.
DOPPMAN, G.
W.
GEELHOED AND V.
Extensive air bronchograrns are seen, especially in the upper lobes.
The majority of them had a lymphoreticular malignancy (either leukemia or lymphoma). In more than half, the underlying malignancy was in remission when the pneumonia developed (.9). A few had primary immunodeficiency diseases. All patients were receiving treatment consisting of either combined chemotherapy, corticosteroid therapy, or wide-spectrum antibiotic therapy. TYPICAL RADIOGRAPHIC FEATURES
The classic radiographic findings of Pneumocystis carinii pneumonia are illustrated in Figure 1. A diffuse bilateral infiltrate is usually seen, perihilar in distribution and radiating out into both lung fields (Fig. 1, A). The apices of the lungs are frequently not involved and apical sparing has been described as a typical radiographic finding, Less commonly seen is relative sparing of the apices and bases with the infiltrate presenting as a truly cen-
Fig.
a.
A and B.
T.
DE VITA
January 1975
tral or perihilar process (Fig. 1, B). Generally, pleural effusion is not seen nor is hilar adenopathy present. The infiltrate is initially a patchy reticulogranular process progressing to a more diffuse alveolar consolidation. Although classically described as an "interstitial pneumonia," acute Pneumocystis pneumonia, as seen in immunosuppressed adults, is predominantly an alveolar or air-space consolidation with a variable but minor interstitial component of lymphoplasmocytic infiltrate. Early acinar involvement is patchy and may be confused with interstitial disease on the chest film but rapid progression leading to coalescence and air bronchograms makes its predominantly alveolar nature evident. Extensive air bronchograms are common and were seen in If) of our 30 cases (53%) (Fig. 2). Forrest (8) and Bragg and Janis (2) have recently commented upon the inaccuracy of referring to Pneumocystis carinii pneumonia as a predominantly interstitial process. Pneumocystis carinii pneumonia is typically an acute inflammatory process and generally progresses from patchy alveolar infiltrate to widespread consolidation in 3-5 days. Of 14 proved fatal cases, 9 were dead within 5 days and 13 within 10 days from onset. The last fatality occurred at 14 days. Successful treatment results in clinical improvement within 48-96 hours but the radiographic findings take longer to resolve. In 16 histologically proved and successfully treated patients, 10 showed complete radiographic clearing within 10 days but (j patients took up to 30 days for complete resolution. Persistent interstitial fibrosis
Note predominant right (A) and left-sided involvement (B) in these 2 proved cases of Pneumocystis carinii pneumonia.
Vo!. 114
ATYPICAL RADIOGRAPHIC FEATURES IN
Pneumocystis carinii
PNEUMONIA
41
Diagnostic Radiology
has been reported (17) following treated Pneumacystis carinii pneumonia but was not observed in our senes. In summary, classic Pneumocystis carinii pneumonia is an acute bilateral perihilar and basilar infiltrate progressing to diffuse alveolar consolidation within 3-4 days and unassociated with adenopathy or pleural changes. In the appropriate clinical setting, this typical radiographic picture is practically diagnostic. However, the incidence of atypical radiographic findings has not been extensively investigated and we therefore reviewed our cases to determine their frequency. ATYPICAL RADIOGRAPHIC FINDINGS
Distribution: Sparing of the apices of the lung was observed in 18 patients but 12 patients or 40% failed to show this pattern on any of the available films. Although 26 of our patients exhibited typical bilateral distribution, 4 individuals or 13% displayed marked unilateral predominance of the Pneumocystis infiltrate (Fig. 3). In no instance, however, was the contralateral lung completely free of disease. In addition, 2 patients (7%) exhibited lobar or segmental consolidation in addition to diffuse involvement (Fig. 4). Although a number of our patients had received mediastinal irradiation, sparing of the paramediastinal irradiated lung, as recently described by Forrest (8), was never observed. However, one patient who had radiotherapy to the left upper
A
Fig. 4.
Diffuse bilateral infiltrates are present in addition to a localized right middle-lobe consolidation.
thorax for breast carcinoma demonstrated sparing of the irradiated left upper lobe when Pneumocystis pneumonia developed during chemotherapy (Fig. .5). Type oj Infiltrate: Two cases of confirmed Pneumocystis pneumonia exhibited a pseudonodular pattern giving rise to some confusion with metastatic processes. Such a pseudonodular pattern has been observed by others (2,18). In addition, 2 patients demonstrated areas of linear atelectasis early in the course of their disease (Fig. 6). In both instances, diaphragms were high and this may have represented a hypoventilatory phenome-
8
Fig. 5. A. Control chest film shows absent left breast, but no evidence of radiation changes in the left upper lobe. left pleural effusion. B. Pneumocysiis infiltrate spares the irradiated left upper lung.
Note malignant
J. L.
42
Fig. 6.
DOPPMAN, G.
W.
GEELHOED AND V.
T.
DE VITA
January 1975
Bilaterallo~er
lobe linear shadows (arrows) in early pneumoma, probably atelectatic changes. Xote incidental right aortic arch. !Jn~umocyslls
non. The atelectasis disappeared as the infiltrate progressed. A single patient demonstrated breakdown in a focal area of consolidation in the left lower lobe. (Fig. 7). At autopsy, widespread Pneumocystis pneumonia with cavitation and acute necrosis was seen. Pneumocystis carinii organisms were present in abundance in the wall of the left lower lobe abscess but Monilia was also cultured from the lung, Pleural Findings: Absence of pleural fluid has been proposed as so characteristic a finding in Pneumocystis pneumonia that a small effusion according to most authors, practically excludes the diagnosis. Forrest (8) recently reported bilateral pleural effusions in 2 of 12 proved cases (17%). One of these patients, however, had a collagenvasc~lar dise~se. Prior to his report, only one previous effusion had been described (11) and in this case, associated heart failure was present. ' In our 3D proved cases, after effusions antedating the p'neumocystis pneumonia or following percutaneous biopsy were carefully excluded, the possibility of small pleural effusions was suggested in () cases or 20%. Portable decubitus films were taken in several patients in an attempt to confirm the p:esencc of sr:rall effusions but were usually technically unsatisfactory in these sick individuals. No thoracenteses were performed. Two of the 6
TABLE
I:
PLEURAL FLUID IN 18 AUTOPSIED PATIENTS' WITH Pneumocysiis PNEUMONIA
None
Less than 50 ml *
More than 75 ml
14 (78%)
2 (11%)
2t (11 %)
16 89%
* Probably undetectable on portable chest films.
t
One had Monilia in addition to Pneumocysiis.
Fig. 7.
Central excavation (arrows) suggests abscess formation.
patients in whom fluid was suspected died; at the pleural spaces were dry. Peripheral mfiltrate can obscure the costophrenic angle and suggest a small pleural effusion. We suspect that 5 o.f. our 6 pleural fluid diagnoses were falsely posrtive buthave proved it in only 2. In order to more fully evaluate the incidence of pleural fluid in Pneumocystis carinii pneumonia, autopsy protocols were reviewed in 18 fatal cases. The presence or absence of pleural fluid was invariably recorded by the prosector. The results are presented in TABLE 1. Fourteen cases, or 78% had dry pleural spaces. Less than 50 ml, probably undetectable on portable chest films, was present in 2 patients and 2 others had larger effusions of 100 and 125 ml. Only one of these was diagnosed roentgenographically and this patient also had a superimposed monilial infection. Certainly, pleural fluid in roentgenographically detectable quantitie's is very rare in uncomplicated Pneumocystis carinii pneumonia. Pneumothoraces, apart from biopsy attempts, were observed in 2 children with Pneumocystis carinii pneumonia. This complication is common in interstitial or plasma cell pneumonia of newborns (3, 4). Robillard et al. (14) reported 5 instances of pneumomediastinum or pneumothorax in 22 infants and all children with this complication ~utopsy,
Va!. 114
ATYPICAL RADIOGRAPHIC FEATURES IN
Pneumocystis carinii
PNEUMONIA
43
Diagnostic Radiology
B
A Fig. 8.
A and B.
Initial chest film (A) and extensive Pneumocystis infiltration 12 hours later (B).
died. Spontaneous pneumothorax was never observed in our adult patients. Hilar prominence suggesting adenopathy was observed in 2 patients. Histologic confirmation was not obtained. In view of the perihilar distribution of the infiltrate, minor degrees of adenopathy could easily go undetected. In addition, hilar adenopathy is a prominent feature of the lymphoreticular diseases so common in this series. A review of autopsy findings in 18 fatal cases revealed hilar or mediastinal adenopathy in 6 patients (33%). However, in every case, the' enlarged nodes were due to the underlying myeloproliferative disorder or non-pneumocystic inflammatory process (2 leukemia; 2 lymphoma; 1 tuberculous infection complicating lupus; and 1 Wiskott-Aldrich syndrome with reticuloendothelial tumor). Progression: Progression of the radiographic findings in Pneumocystis carinii pneumonia from a patchy infiltrate to diffuse consolidation generally occurs over 3-5 days. In 2 cases, one adult and one child, massive consolidation developed within 12 hours (Fig. 8), suggesting some alternate diagnosis such as pulmonary edema or hemorrhage. In several successfully treated patients, clearing was delayed up to six weeks but in no instance were chronic interstitial changes observed in survivors. DISCUSSION
The classic radiographic appearance in the appropriate clinical setting probably justifies a presumptive diagnosis of Pneumocystis carinii pneumonia and the initiation of therapy without histologic confirmation. Although violating basic
bacteriologic principles, such a course of action is justified because percutaneous or open lung biopsy in these dyspneic, often thrombocytopenic patients, is associated with a significant morbidity. Unfortunately, at least half of our 30 proved cases had one or more atypical radiographic findings and, in this group, bacteriologic confirmation by brushing, needle aspiration or biopsy is indicated. All of the atypical radiographic findings that we have illustrated have been previously described. Pneumothorax and pneumomediastinum have been stressed in the pediatric literature (3, 4, (5, 14). Several authors have mentioned instances of asymmetrical distribution (2, 8), lobar consolidation (2,8), pseudonodular infiltrate (2, 18), and pleural effusions (2, 8, 11). From our review, it is apparent that the incidence of atypical radiographic findings is appreciable, 17 of our 30 proved cases or 56% demonstrating at least one such finding. Therefore, histological confirmation will probably be necessary in a significant percentage of cases. If bronchial brushing proves to be as effective as preliminary reports suggest (12), it will undoubedly become the biopsy procedure of choice. Equally distressing is the conclusion from this study that few radiographic findings completely exclude the diagnosis of Pneumocystis. Large pleural effusions and prominent hilar adenopathy probably do. But lobar involvement, unilateral predominance, fulminant progression, tissue breakdown, atelectatic changes and a pseudonodular pattern have been seen in histologically proved Pneumocystis pneumonia. In an immunosuppressed patient, therefore, biopsy may be indicated in the absence of a classic radiographic presentation.
44
J. L.
DOPPMAN, G.
W.
GEELHOED AND V.
REFERENCES 1. Bradshaw M, Myerowitz RL, Schneerson R, et al: Pneurnocystis carinii pneumonitis. Ann Intern Med 73: 775-777. AOV 1970 2. Bragg DG, J anis B: The roentgenographic manifestations of pulmonary opportunistic infections. Am J Roentgenol 117: 798-809, Apr 1973 3. Capitanio MA, Kirkpatrick J A Jr: Pneumocystis carinii pneumonia. Am J Roentgenol 97:174-180, May 1966 4. Cohen WN, McAllister WH: Pneumocystis carinii pneumonia. Report of four cases. Am J Roentgenol 89: 1032-1037, May 1963 5. Ebel KD, Fendel H: The roentgen changes of pneumocystis pneumonia and their anatornic basis. [In] Progress in Pediatric Radiology, Kaufmann H], ed. S Karger, Basel/New York, Vol I, 1967 6. Falkenbach KH, Bachmann KD, O'Loughlin BJ: Pneumocystis carinii pneumonia. Am J Roentgenol85: 706-713, April 1961 7. Feinberg SB, Lester RG, Burke BA: The roentgen findings in pneumocyst.is carinii pneumonia. Radiology 76: 594-599, ApT 1961 8. Forrr st JV: Radiological findings in pneurnocyst is carinii pneumonia. Radiology 103:539-544, j un 1972 9. Geelhoed GW, Powell RD Jr, Doppman JL, et al : Pneumocystis c~rinii pneumonia in cancer patients following ~mml;'nosuppresslve chemotherapy: results of pentamidine isothionat e treatment. Presented at the American Thoracic Society Meeting in New York, May 20-23, 1973 10. Goodell B, Jacobs JB, Powell RD jr, et al: Pneumocystis carinii; the spectrum of diffuse interstitial pneumonia in pa-
T.
DE VITA
January
1975
tients with neoplastic diseases. Ann Intern Med 72 :337-340, Mar 1970 . 11. Jambs J.B, Vogel C, Powell RD Jr, et al: Needle biopsy 111 pneumocystis carmn pneumonia. Radiology 93: 525-530 Sep 1969 ' 12. Reps.her ~~" Schroter .G., Hammon WS: Diagnosis of pneumocystis carmu pneumorutis by means of endobronchial brush biopsy. N Engl J Med 287:340-341,17 Aug 1972 13. Rifkind D, Faris TD, Hill RB Jr: Pneumocystis carinii pneumonia. Studies on the diagnosis and treatment. Ann Intern Med. 65: 943-956, Nov 1966 14. Robillard G, Bertrand R, Gn§goire H, et al: Plasma cell pneumonia in infants. Review of 51 cases. J Canad Assoc Radiol 16: 161-168, Sep 196,5 1.5.. Thomas. SF, Dutz W, Khodadad EJ: Pneumocystis carrnn pneumonia (plasma cell pneumonia). Am J Roentgenol 98:318-322, Oct Hl66 1.6... Vogel C~, Cohen MH, Powel! RD Jr, et al: Pneumocystis carmu pneumonia. Ann Intern Med 68:97-108, Jan 1968 17. Whitcomb ME, Schwarz MI Charles MA et al: Interstitial fibrosis after pneumocystis' carinii pne~monia. Ann Intern Med 73: 761-765, Nov 1970 18: Cross ;\S, Steigbigel RT: Pneumocystis carinii pneumorua presenting as localized nodular densities. N Engl .I Med 291:831-832,17 Oct 1974 .
Department of Diagnostic Radiology Building 10, Room 6S211 National Institutes of Health Bethesda, Md. 20014
