SEPTIC EMBOLI FROM PENETRATING RIGHT ATRIAL FUNGAL MASS

Abstract

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: The learning objectives for this case are to review an uncommon cause of septic emboli as well as diagnosis and management of the infection. CASE PRESENTATION: A 62 year old male with medical history significant for type 1 diabetes mellitus and AML status-post idarubicin and cytarabine with recent pericardiocentesis presented with complaints of dyspnea and pleuritic chest pain. On his initial evaluation in the ED the patient was afebrile with scattered rhonchi. Initial laboratory and imaging work up demonstrated leukocytosis with multifocal regions of nodular opacities consistent with multifocal pneumonia. He was started on broad spectrum antibiotics with Linezolid, Levaquin and Cefepime. CT PE was significant for a focal area of fluid collection at the anterior-inferior right atrium as well as multifocal bilateral airspace disease with cavitation. A transthoracic echocardiogram showed an echogenic mass adjacent to the right atrium with possible invasion into the atrial free wall. Cardiac MR demonstrated a 5.6 x 3.8 cm mass with extensive pericardial contact and extending between the right atrium and ventricle. Biopsy of a cavitary lesion demonstrated fungal organisms with wide ribbon-like hyphae consistent with zygomycete species with cardiac biopsy also showing degenerating fungi. Intravenous amphotericin and micafungin were started for treatment of intracardiac zygomycosis with septic pulmonary emboli. CT surgery was consulted for debulking of the intracardiac mass but felt the patient would be unable to tolerate the surgery. Antifungal medications were continued throughout the hospitalization and he was discharged on amphotericin and posaconazole. Follow-up CT chest around the time of discharge showed a decrease in the size of the atrial mass. DISCUSSION: Zygomycosis, also known as mucormycosis, is a fungal infection which primarily infects immunocompromised patients by angioinvasion and infarction of tissues. The fungi and their spores are commonly found in the environment.[1] Diagnosis is made by histopathology and confirmation with a culture is recommended, but often does not produce fungal growth. Zygomycetes lack the cell wall components tested for on the 1,3-beta-D-glucan or aspergillus glactomannan assays and are therefore negative. Treatment is a combination of surgical debridement and antifungal medication. Initial treatment of choice is with amphotericin B with a step down to posaconazole or isavuconazole.[3] Mortality rates for rhino-orbital-cerebral infection range from 25-62% but are reportedly as high as 87% with pulmonary involvement. [2] CONCLUSIONS: Rhino-orbital-cerebral involvement is the most common clinical presentation of the disease, but this case demonstrates the importance of a thorough differential diagnosis for pneumonia in an immunosuppressed patient.[2] Reference #1: Cox MD, Gary. Mucormycosis (zygomycosis). UpToDate. https://www.uptodate.com. Accessed February 21st, 2019. Reference #2: Roden MM, Zaoutis TE, Buchanan WL, et al. Epidemiology and outcome of zygomycosis: a review of 929 reported cases. Clin Infect Dis 2005; 41:634. Reference #3: Spellberg B, Walsh TJ, Kontoyiannis DP, et al. Recent advances in the management of mucormycosis: from bench to bedside. Clin Infect Dis 2009; 48:1743. DISCLOSURES: No relevant relationships by Richard Belt, source=Web Response