Rare case of low-grade extranodal NK/T-cell lymphoma, nasal type, arising in the setting of chronic rhinosinusitis and harboring a novel N-terminal KIT mutation.

Our case of ENKTCL-NT is unusual due to (1) an indolent clinical course (2) low-grade histopathologic features including a low proliferative index (3) lack of CD56 expression and (4) a novel KIT mutation. This case raises awareness of the existence of a subset of cases of ENKTCL-NT that can potentially be misdiagnosed as a reactive process, particularly in patients with recurrent chronic rhinosinusitis.