An Uncommon Case of Fungal Rhinosinusitis Caused by the Mold Exserohilum rostratum in a Patient with Relapsed Acute Myeloid Leukemia: Case Report and Review of the Literature.

Invasive fungal infections remain a devastating and potentially deadly complication in the setting of immunocompromised patients, such as in the setting of cancer, transplants, and other immune deficiencies. Infection with dematiaceous molds remains a less common but clear and present etiology. We present here a patient with relapsed acute myeloid leukemia who was neutropenic for a prolonged period. Symptoms worsened during the hospital course, including left-sided sinus swelling, which was also noted on imaging. ENT performed a bedside endoscopy and biopsied an eschar forming in the left nasal cavity. This was ultimately found to be acute invasive rhinosinusitis due to infection with the mold Exserohilum rostratum The patient was started on Posaconazole and Amphotericin B. He eventually also underwent surgical debridement. Infections with this organism are very uncommon, as noted in our literature search. In the diagnostic methods employed in this case, we utilized pathology, culture and microscopy, as well as mass spectrometry which was used to confirm the diagnosis.