A69-21 Holes in the Defense: Cavitary Lung Disease from Syncephalastrum in a Vulnerable Host

Abstract Introduction Cavitary lung lesions can have a broad differential in an immunocompromised patient. We present a case of progressively worsening cavitary lung lesions due to Syncephalastrum in a patient with lymphoma on multiple immunosuppressants. This is rarely reported in literature with only one other case documenting cavitation due to this invasive Mucorales species. Case-presentation A 59-year-old female with marginal zone lymphoma with retro-orbital and thoracic involvement presented for minimally productive cough, shortness of breath, weight loss and malaise. She was on dexamethasone for cord compression, rituximab, and bendamustine. Initial chest xray was concerning for a cavitary lesion. Computerized-tomography showed a thick-walled cavity in the left lower lobe and multiple non-calcified nodules in bilateral lungs which had appeared acutely within a month in comparison with prior scans. This suggested an infectious process despite the absence of leukocytosis or fevers. A broad workup for cavitary lung lesions was sent. QuantiFERON gold and sputum for acid-fast bacilli were negative. Sputum culture grew mold. A bronchoalveolar lavage (BAL) was done and she was started on amphotericin B pending results due to her immunocompromised status. Beta-D-Glucan and galactomannan resulted positive, raising high suspicion for Aspergillus and she was switched to voriconazole. However, sputum culture as well as BAL cultures both turned positive for Syncephalastrum species. Amphotericin B was restarted. Posaconazole was added for combination/salvage therapy and was supplemented with intravenous immunoglobulin (IVIG) due to low immunoglobulin levels. Repeat imaging showed new cavitations. Given multi-lobar involvement, she was determined to not be a surgical candidate for resection. Eventually the patient developed intolerance to amphotericin B with severe refractory nausea and inability to tolerate oral intake. Serial imaging showed continued progression of disease. She ultimately opted for hospice care. Discussion Syncephalastrum species belong to Mucorales fungi but are rarely reported to cause pulmonary mucormycosis. In one review of 87 cases, only 1 patient grew Syncephalastrum species. Only 1 other case clearly documenting Syncephalastrum specifically causing cavitary lesions has been reported. This patient was particularly susceptible due to being on multiple immunosuppressants. The positive B-D-Glucan and galactomannan initially pointed towards aspergillus until cultures resulted otherwise, which raises suspicion for co-infections. Mortality remains high regardless of pulmonary or other organ involvement, especially in patients with hematologic malignancies. Prompt diagnosis with initiation of amphotericin B and surgical resection are crucial. Posaconazole is the most promising agent other than amphotericin B, however, further research is needed to establish evidence-based combination regimens. This abstract is funded by: None