NK/T-Cell Lymphoma (Midline Lethal Granuloma)

Lethal midline granuloma is a midfacial necrotizing lesion that is characterized by destructive mucosal lesions of the upper aerodigestive tract. The patients complain of rhinorrhea, epistaxis, nasal stuffiness, obstruction, and pain. The underlying mucosa is thickened and the patient usually develops extensive midfacial destructive lesions, perforated nasal septum and erosion of the nasal bone. The disease is localized to the upper aerodigestive tract at presentation but dissemination to distant sites may occur. Constitutional symptoms may develop. Also referred to as polymorphic reticulosis, midline malignant reticulosis, Stewart’s granuloma most of the lethal midline granulomas are NK/T-cell lymphomas. Untreated, this disease has a very high mortality reaching almost 100% due to septicemia, perforation into blood vessels or penetration into brain leading to abscess. Clinical diagnosis is aided by histopathology that typically reveals granulomatous lesion with a mixed cellular infiltrate of eosinophils, lymphocytes, plasma cells and histiocytes. Angiocentric and angiodestructive pattern is usually seen. Immunohistochemistry (IHC) is positive for T-cell markers. Combined chemotherapy followed by involved field external radiation beam to be beneficial in patients and prolonged progression-free survival rates.