An Unusual Case of Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type Masquerading as Dacryocystitis and Sinusitis.

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (NNKTL) is a rare and highly aggressive non-Hodgkin lymphoma originating from NK or γδ T cells infected by Epstein-Barr virus (EBV). In the United States, NNKTL is usually noted in people of Asian or Hispanic descent. Natural killer/T-cell lymphoma, nasal type commonly involves the upper aerodigestive tract, including the nasopharynx, nasal cavity, Waldeyer's ring, and oropharynx. Extensive local destruction and invasion has been noted, especially of the paranasal sinuses, hard palate, and central nervous system; involvement of the nasolacrimal duct with dacryocystitis is yet to be reported. We report a rare case of a Hispanic man with extranodal NNKTL masquerading as persistent dacryocystitis and necrotizing sinusitis unresponsive to antibiotics and surgical intervention. An extensive background of necrosis and inflammation was noted on pathology, and additional analysis with immunohistochemistry and in situ hybridization after repeat biopsy were necessary for accurate diagnosis.