Propionibacterium acnes Presenting With Mediastinal Lymphadenopathy in the Absence of Sarcoidosis.

SESSION TITLE: Infectious Disease Student/Resident Case Report Posters ISESSION TYPE: Medical Student/Resident Case ReportPRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PMINTRODUCTION: Propionibacterium acnes is a gram positive bacterium that is most commonly associated with the skin condition acne. P. acnes can be found in bronchoalveoloar lavage of approximately 70% of patients with sarcoidosis and is associated with disease activity [1]. It was isolated in high rates and concentrations from lymph nodes in sarcoidosis [2]. We present a case of mediastinal lymphadenopathy secondary to P. acnes in the absence of sarcoidosis.CASE PRESENTATION: A 24-year-old male with no past medical history, medications, or environmental exposures presents with shortness of breath associated with cough. One month prior he had an upper respiratory infection. Chest CT revealed presence of hilar and mediastinal adenopathy. Work up including ACE level, fungal serologies, IgE levels, and serum quantiferon gold were all unrevealing. He then underwent fiberoptic bronchoscopy. Multiple biopsies, washings, and brushings did not yield a diagnosis. Notably, there was an absence of granulomas. Due to concern for lymphoma, given a positive family history, mediastinoscopy was performed. Pathology of the lymph nodes unmasked gram positive anaerobe, P. acnes. Doxycycline was started. Symptomatic improvement was noted at follow up visit. Repeat chest CT noted improvement in hilar and mediastinal adenopathy.DISCUSSION: Although P. acnes is most commonly recognized for skin acne, its role in mediastinal lymphadenopathy has been described in sarcoidosis. Here we describe a case of P. acnes in the absence of sarcoidosis. We bring to light the rare occurrence of P. acnes mediastinal lymphadenopathy to bring awareness to the condition which is often overlooked in the absence of sarcoidosis. We demonstrate the importance of including P. acnes in the differential of mediastinal lymphadenopathy.CONCLUSIONS: This case illustrates the need to consider P. acnes in cases with mediastinal lymphadenopathy, even in the absence of sarcoidosis. Early diagnosis can lead to avoidance of unnecessary testing and early treatment.Reference #1: Hiramatsu, J, et al. Propionibacterium acnes DNA detected in bronchoalveolar lavage cells from patients with sarcoidosis. Sarcoidosis, vasculitis, and diffuse lung diseases 2003:197-203Reference #2: Nihon, N et al, The Journal of the Japanese Society of Internal Medicine (2003) 92: 7,1492-1497DISCLOSURE: The following authors have nothing to disclose: Anita Rajagopal, Krishnan RajagopalNo Product/Research Disclosure Information.