A Mirage: Endobronchial Actinomycosis Mimicking Carcinoid Tumor

Abstract

SESSION TITLE: Fellow Case Report Poster - Lung Pathology SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Pulmonary actinomycosis is rare infection caused by Actinomyces spp., an anaerobic Gram-positive bacteria. Endobronchial involvement is very rare in pulmonary actinomycosis. We present a case of a 64 year old woman with chronic cough who had an endobronchial lesion mimicking carcinoid tumor. CASE PRESENTATION: 64 year old female with history of emphysema, presented to the emergency room with chronic non-productive for one year. On presentation her vital signs were normal. Physical exam was significant for focal wheezing at right lung base. Chest X-ray was and laboratory data were normal. Computed tomography scan of the chest showed narrowing of the bronchus intermedius with a radiopaque density with no lymphadenopathy. Bronchoscopy revealed narrowing of the bronchus intermedius with a smooth rounded, reddish pedunculated endobronchial mass. Biopsy of the mass revealed no malignancy, and a filamentous, gram positive, acid fast stain negative organism consistent with Actinomyces. Patient received six weeks of intravenous Penicillin, followed by 20 weeks of oral Penicillin VK. Patient returned to pulmonary clinic six months later with resolution of cough. DISCUSSION: Endobronchial actonomycosis is caused by Actinomyces spp., an anaerobic Gram-positive bacteria that normally colonizes the digestive and genital tracts. Pulmonary actinomycosis is more common in males, and results from aspiration of oropharyngeal or gastrointestinal contents. Respiratory symptoms include cough, sputum production, and pleuritic chest pain. Laboratory data will generally be normal. Diagnosis can be challenging, as up to 25% of cases are initially misdiagnosed as malignancy. Diagnostic properties include positive culture and demonstration of sulphur granules, with clinical and radiographic correlation. Fiberoptic bronchoscopy is usually non-diagnostic unless there is clear endobronchial lesion which is biopsied. The lesion will demonstrate an irregular submucosal tumor with granular thickening that is partially obscuring the bronchi. Treatment entails 6 months of penicillin therapy, with tetracycline and erythromycin being second line agents. CONCLUSIONS: Endobronchial actinomycosis is an extremely rare infection resulting from aspiration of oropharyngeal contents. On bronchoscopy it frequently mimics malignancy, and up to 25% of cases are initially misdiagnosed as cancer. Treatment entails a prolonged course of penicillin therapy. Reference #1: Mabeza, G.F., Macfarlane, J., Pulmonary actinomycosis. Eur Respir J 2003; 21: 545-551 DISCLOSURE: The following authors have nothing to disclose: Yuriy Takhalov, John Kileci, Samir Abdelhadi No Product/Research Disclosure Information