562559
research-article2014
CPJXXX10.1177/0009922814562559Clinical PediatricsKrenek et al
Resident Round
Nine-Year-Old Girl With a Left Flank Mass
Clinical Pediatrics 2015, Vol. 54(7) 703–705 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0009922814562559 cpj.sagepub.com
Lauren M. Krenek, MD1, Karen W. Eldin, MD2, and Carol J. Baker, MD1,3 Case Report A 9-year-old girl, previously healthy except for mild asthma, presented to the emergency department with a 1-day history of a visible, painful mass over her left posterior rib cage without other symptoms. There was no history of trauma to the flank, exposure to animals or unpasteurized dairy products, or travel beyond the greater Houston area. A diagnosis of “muscle spasm” was made by the emergency department physician; heat and ibuprofen were recommended. The mass increased in size and became more painful over the next 6 days. She returned to the emergency department where her oral temperature was 100.2°F. Computed tomography imaging of chest and abdomen demonstrated 2 masses, one in the lower lobe of the left lung (Figure 1A) and the other on the left thoracic wall. A presumptive diagnosis of rhabdomyosarcoma was made and she was referred to our children’s cancer center. On physical examination, her temperature was 98.0°F, pulse 88 beats/min, and respiratory rate 22 per minute. She was crying with pain, but did not appear toxic. Examination of her nose, ears, and throat were unremarkable. The remainder of the examination was unremarkable except for a 4 × 7 cm firm, tender, slightly warm, and erythematous mass over the left posterior rib cage. Her breath sounds were diminished over the left lower lobe. Laboratory findings revealed a white blood cell count of 14.05 × 109 cells/L with a normal differential count and an erythrocyte sedimentation rate of 89 mm/h. Serum chemistries, liver panel, uric acid, and lactate dehydrogenase were normal. Bone marrow biopsy showed normal cellularity and unremarkable cellular morphology, and flow cytometry did not detect abnormal cells. Contrast-enhanced magnetic resonance imaging of the chest and abdomen demonstrated 2 heterogeneously enhancing masses, one at the dome of the diaphragm measuring 4.5 × 4.7 × 2.6 cm in the lower lobe of the left lung and the other measuring 7.1 × 4.2 × 3.5 cm within the musculature of the left abdominal wall surrounding the left 10th and 11th lateral ribs, which displaced adjacent bowel, spleen, and left kidney (Figure 1B). A computed tomography–guided needle aspiration of the 2 masses was performed. The left lung lower lobe mass had mixed inflammation and no evidence of malignancy;
the left flank mass showed necrotic and viable skeletal muscle with acute inflammation but no malignancy. Gram, acid-fast, and fungal stains of these biopsy specimens were negative so additional biopsy was advised. Thoracotomy biopsy specimens of the pleural-based and flank masses revealed filamentous branching grampositive rods and a small sulfur granule, indicative of Actinomyces spp infection (Figure 2). Although the bacterial cultures of the first and second biopsy specimens were sterile, the child had received intravenous antibiotics before each procedure that would have inhibited growth of Actinomyces spp.
Final Diagnosis Thoracic actinomycosis.
Hospital Course High-dose intravenous penicillin was administered for 4 weeks followed by oral penicillin for another 5 months. Contrast-enhanced magnetic resonance imaging of the chest at the end of therapy showed complete resolution of the flank mass and a 6-mm nonenhancing fibrotic lesion in the left lower lobe.
Discussion Actinomyces spp are filamentous, branching, gram-positive, pleomorphic non–spore forming anaerobic or microaerophilic bacilli.1 They often are opportunistic pathogens of low virulence that are found in the oral, gastrointestinal, and genital flora that cause indolent infections when 1
epartment of Pediatrics, Baylor College of Medicine, Houston, D TX, USA 2 Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA 3 Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA Corresponding Author: Carol J. Baker, Section of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine, 1102 Bates Street, Suite 1120, Houston, TX, USA. Email: [email protected]
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Clinical Pediatrics 54(7)
Figure 1. Computed tomography scan of the chest (A) reveals an irregularly shaped left lung mass that extends to the dome of the diaphragm (large arrow). On further review of this imaging study, it became clear that this mass was contiguous with the posterior flank mass and both masses were within the thoracic cavity. T2-weighted magnetic resonance image (B) demonstrates a heterogeneously enhancing mass surrounding the 10th and 11th ribs (small arrows) and displacing the abdominal organs. The inflammation extends from the mass to encompass the entire thoracic level (large arrows), strongly suggesting an infectious etiology rather than malignancy.
Figure 2. Biopsy of lower thoracic (flank) mass demonstrate filamentous branching gram-positive rods (A) and a small sulfur granule (B) by hematoxylin–eosin stain (magnification 400×).
disease occurs. Invasion of the lung typically occurs after aspiration, allowing growth of Actinomyces spp without regard to tissue or fascial planes. The latter characteristic was a clinical clue in our patient and on further review of her imaging studies, the 2 masses were actually one. Furthermore, the diffuse inflammation seen by contrastenhanced T2-weighted magnetic resonance images is consistent with an infectious rather than a malignant process (Figure 1B). The chronic inflammatory lesions of actinomycosis can form abscesses, sinus tracts, fistulae, and
tissue fibrosis. The most common body site, especially in children, is cervicofacial, but thoracic, abdominal, and pelvic infections can also occur (eg, following inoculation by oral surgery, dental infection, gastrointestinal foreign body or trauma). Thoracic actinomycosis is uncommon in children but may be underrecognized.2 Most patients are male and have conditions predisposing to aspiration (eg, dental procedures with poor dentition, neurologic impairment), but some, as was the case for our patient, have no discernable
705
Krenek et al preceding event. Presenting findings may include a chest wall mass (~50% of children), cough, pain (back, chest, shoulder), and weight loss; Fever occurs less commonly.2 The diagnosis often is delayed because fibrous masses are mistaken for malignancy.3-5 Culture diagnosis is difficult because Actinomyces spp require enriched medium in anaerobic conditions for up to 21 days and treatment before biopsy can prevent identification.1 Biopsy is the diagnostic method of choice but adequate tissue specimens must be obtained and, because of the rarity of this condition, interpretation by an experienced pathologist is required.
Conclusion This patient demonstrates several important points for the pediatrician. First, although malignancy should be a differential consideration, the inflammatory nature of the flank mass, expressed as severe pain, tenderness on palpation, and erythema, should favor infection rather than a soft tissue or muscle malignancy. Second, the rarity of thoracic actinomycosis may lead to a presumptive diagnosis of malignancy by imaging studies. It is important, as this case illustrates, to review the imaging studies with the most experienced radiologist available. Third, as in many difficult cases, tissue diagnosis requires adequate sampling and communication with the pathologist to assure that actinomycosis is carefully considered in the review of a mass that crosses fascial planes.6
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Ryan KJ, Drew WL. Actinomyces and nocardia. In: Ryan KJ, Ray C., eds. Sherris Medical Microbiology. 5th ed. New York, NY: McGraw-Hill; 2010:507-514. 2. Bartlett AJ, Rivera AL, Krishnamurthy R, Baker CJ. Thoracic actinomycosis in children. Pediatr Infect Dis J. 2008;27:165-169. 3. Hachitanda Y, Nakagawara A, Ikeda K. An unusual anterior chest wall tumor due to actinomycosis in a child. Pediatr Radiol. 1989;20:96. 4. Wu CY, Li YW. Multifocal thoracic actinomycosis simulating lymphoma. Pediatr Radiol. 1993;23:541-542. 5. Pinarli FG, Mutlu B, Celenk C, et al. Pulmonary actinomycosis mimicking chest wall tumor in a child. Jpn J Infect Dis. 2005;58:247-249. 6. American Academy of Pediatrics. Actinomycosis. In: Pickering LK, Baker CJ, Kimberlin DW, Long SS, eds. Redbook: 2012 Report of the Committee on Infectious Disease. 29th ed. Elk Grove, IL: American Academy of Pediatrics; 2012:219-220.
Copyright of Clinical Pediatrics is the property of Sage Publications Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
research-article2014
CPJXXX10.1177/0009922814562559Clinical PediatricsKrenek et al
Resident Round
Nine-Year-Old Girl With a Left Flank Mass
Clinical Pediatrics 2015, Vol. 54(7) 703–705 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0009922814562559 cpj.sagepub.com
Lauren M. Krenek, MD1, Karen W. Eldin, MD2, and Carol J. Baker, MD1,3 Case Report A 9-year-old girl, previously healthy except for mild asthma, presented to the emergency department with a 1-day history of a visible, painful mass over her left posterior rib cage without other symptoms. There was no history of trauma to the flank, exposure to animals or unpasteurized dairy products, or travel beyond the greater Houston area. A diagnosis of “muscle spasm” was made by the emergency department physician; heat and ibuprofen were recommended. The mass increased in size and became more painful over the next 6 days. She returned to the emergency department where her oral temperature was 100.2°F. Computed tomography imaging of chest and abdomen demonstrated 2 masses, one in the lower lobe of the left lung (Figure 1A) and the other on the left thoracic wall. A presumptive diagnosis of rhabdomyosarcoma was made and she was referred to our children’s cancer center. On physical examination, her temperature was 98.0°F, pulse 88 beats/min, and respiratory rate 22 per minute. She was crying with pain, but did not appear toxic. Examination of her nose, ears, and throat were unremarkable. The remainder of the examination was unremarkable except for a 4 × 7 cm firm, tender, slightly warm, and erythematous mass over the left posterior rib cage. Her breath sounds were diminished over the left lower lobe. Laboratory findings revealed a white blood cell count of 14.05 × 109 cells/L with a normal differential count and an erythrocyte sedimentation rate of 89 mm/h. Serum chemistries, liver panel, uric acid, and lactate dehydrogenase were normal. Bone marrow biopsy showed normal cellularity and unremarkable cellular morphology, and flow cytometry did not detect abnormal cells. Contrast-enhanced magnetic resonance imaging of the chest and abdomen demonstrated 2 heterogeneously enhancing masses, one at the dome of the diaphragm measuring 4.5 × 4.7 × 2.6 cm in the lower lobe of the left lung and the other measuring 7.1 × 4.2 × 3.5 cm within the musculature of the left abdominal wall surrounding the left 10th and 11th lateral ribs, which displaced adjacent bowel, spleen, and left kidney (Figure 1B). A computed tomography–guided needle aspiration of the 2 masses was performed. The left lung lower lobe mass had mixed inflammation and no evidence of malignancy;
the left flank mass showed necrotic and viable skeletal muscle with acute inflammation but no malignancy. Gram, acid-fast, and fungal stains of these biopsy specimens were negative so additional biopsy was advised. Thoracotomy biopsy specimens of the pleural-based and flank masses revealed filamentous branching grampositive rods and a small sulfur granule, indicative of Actinomyces spp infection (Figure 2). Although the bacterial cultures of the first and second biopsy specimens were sterile, the child had received intravenous antibiotics before each procedure that would have inhibited growth of Actinomyces spp.
Final Diagnosis Thoracic actinomycosis.
Hospital Course High-dose intravenous penicillin was administered for 4 weeks followed by oral penicillin for another 5 months. Contrast-enhanced magnetic resonance imaging of the chest at the end of therapy showed complete resolution of the flank mass and a 6-mm nonenhancing fibrotic lesion in the left lower lobe.
Discussion Actinomyces spp are filamentous, branching, gram-positive, pleomorphic non–spore forming anaerobic or microaerophilic bacilli.1 They often are opportunistic pathogens of low virulence that are found in the oral, gastrointestinal, and genital flora that cause indolent infections when 1
epartment of Pediatrics, Baylor College of Medicine, Houston, D TX, USA 2 Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA 3 Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA Corresponding Author: Carol J. Baker, Section of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine, 1102 Bates Street, Suite 1120, Houston, TX, USA. Email: [email protected]
704
Clinical Pediatrics 54(7)
Figure 1. Computed tomography scan of the chest (A) reveals an irregularly shaped left lung mass that extends to the dome of the diaphragm (large arrow). On further review of this imaging study, it became clear that this mass was contiguous with the posterior flank mass and both masses were within the thoracic cavity. T2-weighted magnetic resonance image (B) demonstrates a heterogeneously enhancing mass surrounding the 10th and 11th ribs (small arrows) and displacing the abdominal organs. The inflammation extends from the mass to encompass the entire thoracic level (large arrows), strongly suggesting an infectious etiology rather than malignancy.
Figure 2. Biopsy of lower thoracic (flank) mass demonstrate filamentous branching gram-positive rods (A) and a small sulfur granule (B) by hematoxylin–eosin stain (magnification 400×).
disease occurs. Invasion of the lung typically occurs after aspiration, allowing growth of Actinomyces spp without regard to tissue or fascial planes. The latter characteristic was a clinical clue in our patient and on further review of her imaging studies, the 2 masses were actually one. Furthermore, the diffuse inflammation seen by contrastenhanced T2-weighted magnetic resonance images is consistent with an infectious rather than a malignant process (Figure 1B). The chronic inflammatory lesions of actinomycosis can form abscesses, sinus tracts, fistulae, and
tissue fibrosis. The most common body site, especially in children, is cervicofacial, but thoracic, abdominal, and pelvic infections can also occur (eg, following inoculation by oral surgery, dental infection, gastrointestinal foreign body or trauma). Thoracic actinomycosis is uncommon in children but may be underrecognized.2 Most patients are male and have conditions predisposing to aspiration (eg, dental procedures with poor dentition, neurologic impairment), but some, as was the case for our patient, have no discernable
705
Krenek et al preceding event. Presenting findings may include a chest wall mass (~50% of children), cough, pain (back, chest, shoulder), and weight loss; Fever occurs less commonly.2 The diagnosis often is delayed because fibrous masses are mistaken for malignancy.3-5 Culture diagnosis is difficult because Actinomyces spp require enriched medium in anaerobic conditions for up to 21 days and treatment before biopsy can prevent identification.1 Biopsy is the diagnostic method of choice but adequate tissue specimens must be obtained and, because of the rarity of this condition, interpretation by an experienced pathologist is required.
Conclusion This patient demonstrates several important points for the pediatrician. First, although malignancy should be a differential consideration, the inflammatory nature of the flank mass, expressed as severe pain, tenderness on palpation, and erythema, should favor infection rather than a soft tissue or muscle malignancy. Second, the rarity of thoracic actinomycosis may lead to a presumptive diagnosis of malignancy by imaging studies. It is important, as this case illustrates, to review the imaging studies with the most experienced radiologist available. Third, as in many difficult cases, tissue diagnosis requires adequate sampling and communication with the pathologist to assure that actinomycosis is carefully considered in the review of a mass that crosses fascial planes.6
Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Ryan KJ, Drew WL. Actinomyces and nocardia. In: Ryan KJ, Ray C., eds. Sherris Medical Microbiology. 5th ed. New York, NY: McGraw-Hill; 2010:507-514. 2. Bartlett AJ, Rivera AL, Krishnamurthy R, Baker CJ. Thoracic actinomycosis in children. Pediatr Infect Dis J. 2008;27:165-169. 3. Hachitanda Y, Nakagawara A, Ikeda K. An unusual anterior chest wall tumor due to actinomycosis in a child. Pediatr Radiol. 1989;20:96. 4. Wu CY, Li YW. Multifocal thoracic actinomycosis simulating lymphoma. Pediatr Radiol. 1993;23:541-542. 5. Pinarli FG, Mutlu B, Celenk C, et al. Pulmonary actinomycosis mimicking chest wall tumor in a child. Jpn J Infect Dis. 2005;58:247-249. 6. American Academy of Pediatrics. Actinomycosis. In: Pickering LK, Baker CJ, Kimberlin DW, Long SS, eds. Redbook: 2012 Report of the Committee on Infectious Disease. 29th ed. Elk Grove, IL: American Academy of Pediatrics; 2012:219-220.
Copyright of Clinical Pediatrics is the property of Sage Publications Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
