A CASE OF MEDIASTINAL ABSCESS AS A COMPLICATION OF ENDOBRONCHIAL ULTRASOUND TRANSBRONCHIAL NEEDLE ASPIRATION

Abstract

SESSION TITLE: Medical Student/Resident Procedures Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Limited literature is available regarding the clinical presentation and management of EBUS-TBNA’s complications. We report a case of mediastinal abscess post-EBUS-TBNA and discuss its management. CASE PRESENTATION: A 44 years old woman presented in 2018 with a history of chest pain radiating to her back. She immigrated to Canada in 2015 from Mauritania. She was a former smoker of 4 pack-years. Her HIV serology was negative, and she was not immunocompromised nor previously exposed to tuberculosis. Chest CT-scan revealed a 1.5cm right lower paratracheal lymphadenopathy. EBUS-TBNA was performed on April 11th, 2019. Lymph node #4R was punctured 9 times. The immediate post-procedure period was uneventful, and the patient was discharged the same day. Histopathology revealed necrotic granulomas with 3 to 5 µm yeast-like organisms on Grocott stain. No neoplastic cells were seen. Auramine, Ziehl-Nielsen and PAS diastase stains and direct M. tuberculosis PCR were negative. A presumptive diagnosis of Histoplasma lymphadenitis was made. Serum and urinary Histoplasma antigen assays sampled 2 weeks later were positive. Antifungal treatment was omitted given the spontaneous improvement in symptoms. Seven days post-procedure, the patient complained of fatigue, chills, chest pain and dyspnea. She came to the emergency department on April 26th with persistent fever (39,4°C), and odynophagia. A chest CT scan revealed an enlarged #4R node (42X26mm) with a heterogeneous content and necrotic material. Mediastinal abscess was suspected and IV piperacillin-tazobactam was initiated. She had little improvement in her chest pain at 48 hours of therapy and remained febrile. Therefore, a mediastinoscopy was done on April 28th. Peri-operative findings consisted of enlarged lymph nodes and frank mediastinal pus, which were sampled, debrided and thoroughly washed. Bacterial cultures were positive for Streptococcus anginosus and oxacillin-susceptible S. epidermidis and negative for fungi. The patient completed a 28 days regimen of piperacillin-tazobactam 4.5g IV q8h. A chest CT scan made on June 14th showed a regression of the mediastinal nodes. As of January 2020, no recurrence of mediastinitis was observed. DISCUSSION: We sought to report post-EBUS-TBNA mediastinal abscess in the context of Histoplasma lymphadenitis. Although rare, one must be aware of the presentation of post-EBUS mediastinitis which can occur from 5 days (2) up to 32 days(3) post procedure. Once mediastinal abscess is diagnosed, a treatment of IV antibiotics can be considered for mild cases but mediastinal drainage should be considered for more severe ones. CONCLUSIONS: In conclusion, we reported a case of post-EBUS-TBNA mediastinal abscess in the context of Histoplasma lymphadenitis. The combination of mediastinal drainage and IV antibiotics led to clinical remission. Reference #1: Wheat LJ, Freifeld AG, Kleiman MB, Baddley JW, McKinsey DS, Loyd JE, Kauffman CA. Clinical practice guidelines for the management of patients with histoplasmosis: 2007 update by the Infectious Diseases Society of America. Clinical Infectious Diseases. 2007 Oct 1;45(7):807-25. Reference #2: Dai JH, Chen LL, Li H, Miao LY, Li R, Gao L, Meng FQ, Cai HR. Severe mediastinal abscess after endobronchial ultrasound with transbronchial needle aspiration. Chinese Medical Journal. 2018 Feb 5;131(3):357-58. Reference #3: Kouskov OS, Almeida FA, Eapen GA, Uzbeck M, Deffebach M. Mediastinal infection after ultrasound-guided needle aspiration. Journal of Bronchology & Interventional Pulmonology. 2010 Oct 1;17(4):338-41. DISCLOSURES: No relevant relationships by Mario Dugas, source=Web Response No relevant relationships by Sebastien Nguyen, source=Web Response No relevant relationships by Bich Nguyen, source=Web Response No relevant relationships by Marc-André Smith, source=Web Response No relevant relationships by Alexandre Tayler-Gomez, source=Web Response