Nasal Type Extranodal NK/T-Cell Lymphoma

**Semantic type:** Neoplastic Process

**Definition:** An aggressive, predominantly extranodal, mature T-cell non-Hodgkin lymphoma. It is characterized by an often angiocentric and angiodestructive cellular infiltrate composed of EBV positive NK/T cells. The nasal cavity is the most common site of involvement. Patients often present with midfacial destructive lesions (lethal midline granuloma). The disease may disseminate rapidly to various anatomic sites including the gastrointestinal tract, skin, testis, and cervical lymph nodes. It is also known as angiocentric T-cell lymphoma. The term "polymorphic reticulosis" has been widely used to describe the morphologic changes seen in this type of lymphoma. However, the latter term may also apply to lymphomatoid granulomatosis, which is an angiocentric and angiodestructive EBV positive B-cell lymphoproliferative disorder.

**Synonyms:** - Angiocentric T-Cell Lymphoma - Angiocentric T-Cell Lymphoma - Angiocentric T-cell lymphoma - Extranodal NK/T lymphoma-nasal - Extranodal NK/T-Cell Lymphoma - Extranodal NK/T-Cell Lymphoma, Nasal Type - Extranodal NK/T-cell lymphoma, nasal type - Extranodal NK/T-cell lymphoma, nasal type - Extranodal NK/T-cell lymphoma, nasal type - NK/T-cell lymphoma, nasal and nasal-type - RETICULOSIS, MALIGNANT - T/NK-cell lymphoma