Metastatic sinonasal malignancies of colorectal origin: Case report and comprehensive review of the literature.

Primary adenocarcinomas represent a small percentage of sinonasal malignancies. Metastasis of colorectal malignancies to the paranasal sinuses is rare, poorly understood, and typically fatal. This case documents an unusual source of metastatic sinonasal malignancy and offers comparison to a cohort of similar patients found in the literature.