Natural killer T-cell lymphoma causing bilateral recurrent recalcitrant dacryocystitis.

A 35-year-old female with a history of chronic extensive rhinosinusitis, previously treated twice with functional endoscopic sinus surgery, presented with recurrent dacryocystitis despite prior dacryocystorhinostomy. Histopathological specimens taken at the most recent sinus surgery demonstrated a lymphocytic inflammatory reaction without evidence of angiodestruction or necrosis. Flow cytometry was normal. Over the following 9 months, the patient developed worsening hypertelorism and bilateral recurrent acute dacryocystitis with a fistula tract to the skin. Neuroimaging revealed a hyperintense enhancing soft tissue expansion into the periorbital regions, invading the nasolacrimal canals, and obstructing the paranasal sinuses. A skin biopsy at the fistula site revealed natural killer T-cell lymphoma. Metastatic work-up disclosed lung, spleen, and bone marrow involvement. The patient underwent chemotherapy with mixed clinical response, and ultimately passed away from metastatic disease. The authors present a rare case of natural killer T-cell lymphoma involving the nasolacrimal sac, presenting as recurrent dacryocystitis and diagnosed by skin biopsy of the fistula site.