Rhizomucor, the Terribly Invasive Fungal Species That Obliterates Everything in Its Path

Abstract

INTRODUCTION:Mucormycosis is an opportunistic fungal infection caused by the ubiquitous filamentous fungi, Rhizomucor spp, a species of fungus associated with high mortality rates. Although it has been documented to affect every organ system, the most common sites are rhinocerberal, lungs, and skin, with dissemination in 23% of cases. Here we present a rare yet fatal case of an immunocompromised individual with confirmed pulmonary mucormycosis associated with diaphragmatic rupture.CASE PRESENTATION: 54-year-old male with history of CAD, CHF, Afib, antiphospholipid syndrome, IPF, and ESRD who initially presented with worsening shortness of breath while receiving hemodialysis. Patient was previously hospitalized two weeks prior to arrival for possible IPF flare and was discharged on short course of PO steroids. On arrival, the patient was found to have leukocytosis and airspace disease in the left lower lobe. He was admitted for suspected HCAP. His sputum culture grew normal flora and leukocytosis improved on broad spectrum antibiotics. Prednisone was also started for suspected IPF flare. On day 3, bronchoscopy with BAL was performed to r/o other opportunistic infections. On day 5, patient's respiratory status and blood pressure abruptly declined requiring intubation. CXR revealed left pneumothorax and pneumoperitoneum. Chest tube was placed and he was transferred to the ICU. CT abdomen/pelvis revealed a left pneumothorax, diaphragmatic rupture, hematoma in the left upper abdomen, moderate free intraperitoneal air, and extensive subcutaneous emphysema. At this time, BAL cultures came back positive for Rhizomucor. CT surgery was consulted for possible intervention, however, prior to initiating treatment, the patient went into PEA arrest and later expired.DISCUSSION: Upon review of the imaging and lab findings, it was determined that the patient likely swallowed a mucor spore that later proliferated in the acidic environment of the gut leading to gastric perforation, and eventually, diaphragmatic rupture; a rare complication discussed in a 2018 case report. A presumed mechanism of action proposed by prior studies has shown mucor's ability to traverse across tissue planes. CONCLUSIONS:The rapid decline in this case made it difficult for healthcare providers to respond in a timely manner. Therefore, it is important for physicians to have a high index of suspicion for mucormycosis in patients on steroids as these infections can progress rapidly if not identified and treated early in the hospital course. Case reports have shown that even on a short steroid taper mucor infections may occur.