Invasive granulomatous cryptococcal sinusitis in an adult with multiple myeloma.

We report a case of cryptococcal sinusitis, a rare presentation of Cryptococcus neoformans infection in a patient with multiple myeloma. The objective of this case report is to highlight the utility of structural and functional imaging modalities in the differential diagnosis of sinonasal soft tissue masses in the immunocompromised patient population. PET-CT was the first imaging modality in this patient, who presented for routine follow-up staging of multiple myeloma, and was asymptomatic at the time of his presentation. PET-CT findings prompted further evaluation with MRI, to aid in the differential diagnosis with respect to a neoplastic versus infectious etiology. Ultimately, surgical excision with histopathology was required to provide definitive diagnosis. Final histopathology displayed yeast-organism staining consistent with Cryptococcus neoformans/gatti. The patient subsequently underwent treatment for this infection, along continued treatment for multiple myeloma. To our knowledge this is the first known case of cryptococcal sinusitis in a patient with neoplastic disease. Imaging represents an important tool to differentiate fungal infection from neoplasm in the immunocompromised patient population. As the population of immunocompromised patients continues to grow, the relevance of this diagnosis as well as the use of alternative imaging modalities is becoming more important in clinical practice.