Hematopoietic Neoplasms of the Sinonasal Tract.

Hematologic malignancies are one of the more common neoplasms to occur in the sinonasal tract and include a wide range of entities, including mature and immature B cell and T cell neoplasms as well as plasma cell dyscrasias and histiocytic disorders. CD45 expression can be helpful in identifying many, but not all, hematopoietic neoplasms in the sinonasal tract, and more extensive immunophenotyping, including EBV in situ hybridization, as well as correlation with genetic results and clinical features may be required for diagnosis.