Disseminated Endobronchial Nocardiosis Masquerading as a Bronchogenic Tumor

Abstract

SESSION TITLE: Lung Pathology 1 SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Nocardia is a weak gram positive, partial acid fast branching filamentous organism. Pulmonary Nocardiosis is infrequently reported in immunocompetent patients and delay in diagnosis occurs due to non-specific clinical symptoms and radiological signs [1]. Our case highlights an unusual presentation of disseminated endobronchial Nocardiosis, initially mistaken for metastatic lung cancer. CASE PRESENTATION: A previously healthy 61-year-old male presented with a worsening right occipital headache. He denied any changes in vision. No fever, chills, anorexia, cough or shortness of breath were reported. His physical examination was unremarkable. Laboratory work up was unrevealing. A Computed Tomography (CT) of the head showed three hypoattenuating lesions in the right cerebral convexity (figure 1). A PET/CT of the body was obtained for concerns of metastatic disease and showed two infrahilar nodules and a right sided subcarinal lymph node with high FDG avidity suspicious for malignancy. These findings prompted a diagnostic bronchoscopy with EBUS-FNA of an endobronchial lesion found in the bronchus intermedius (figure 2). The pathology was negative for malignancy but cultures grew Nocardia. Speciation later showed Nocardia wallacei. A biopsy of the right occipital brain lesion was also consistent with Nocardia. The patient was started on trimethoprim-sulfamethoxazole and imipenem. His follow up visit with repeat CT imaging showed an interval decrease in the size of the right infrahilar mass. DISCUSSION: Pulmonary Nocardiosis has been rarely reported in immunocompetent individuals. Risk factors for this opportunistic infection include solid organ transplant, leukemia, steroid use and HIV [2]. Diagnosis of pulmonary Nocardiosis is usually heralded by the insidious onset of fever, anorexia, cough or shortness of breath. Our patient had a unique presentation with symptoms related to brain dissemination but had absent pulmonary symptomatology [2]. Radiological features of Nocardia in lungs include lobar infiltrates, nodules or cavitary lesions. Treatment consists of a combination of sulfonamides and Imipenem [3]. CONCLUSIONS: We hereby present a rare case of pulmonary Nocardiosis with dissemination to brain in an immunocompetent host. The presentation mimicked malignancy. Our case highlighted the importance of including pulmonary Nocardia in the differential diagnosis of lung nodules with brain lesions even in the absence of respiratory symptoms or known factors of immunosuppression. Reference #1: Ramana KV, Sabitha K, Venkata Bharatkumar P, Sharada CHV, Ratna Rao, Ratna Mani, Sanjeev DR: Invasive Fungal Infections: A Comprehensive Review. American Journal of Infectious Diseases and Microbiology. 2013, 1:64-69 Reference #2: Martínez Tomas R, Menéndez Villanueva R, Reyes Calzada S, et al: Pulmonary nocardiosis: risk factors and outcomes. Respirology. 2007, 12:394-400 Reference #3: Shariff M, Gunasekaran J: Pulmonary Nocardiosis: Review of cases and an update. Canadian Respiratory Journal. 2016:749202 DISCLOSURE: The following authors have nothing to disclose: Sara Assaf, Pujan Patel, David Stoeckel No Product/Research Disclosure Information