[Extra-nodal NK/T-cell lymphoma, nasal type presenting as orbital cellulitis].

Extra-nodal NK/T-cell lymphoma, nasal type, is a rare form of malignant non-Hodgkin's lymphomas. It poses a diagnostic problem due to nonspecific symptoms. We report a case of NK/T-cell lymphoma simulating orbital cellulitis. The study involved a 46-year old female patient followed up for Behçet's disease. The patient was admitted with orbital cellulitis. CT scan of the midface showed pansinusitis with orbital infiltration.The patient had no improvement under antibiotic therapy. Surgical treatment with biopsy was performed. Histological examination showed inflammatory vasculitis and the patient underwent corticosteroid therapy with clinical improvement. The patient had recurrence requiring reoperation with ethmoid biopsies whose histological examination showed NK/T-cell lymphoma, nasal type. Treatment was based on radiochemotherapy and the patient died after two months. NK/T-cell lymphomas are aggressive, they primarily affect the nasal cavities and sinus. They cause angiodestruction and necrosis, resulting in unspecific symptoms. Biopsies are often negative, posing a problem of differential diagnosis. Treatment is based on radiotherapy and chemotherapy. Prognosis is reserved.