Extranodal NK/T Cell Lymphoma, Nasal Type
Definition
- Polymorphic extranodal lymphoma, expressing NK or rarely cytotoxic T cell phenotype
Alternate/Historical Names
- Polymorphic reticulosis
- Lethal midline granuloma
- Angiocentric T cell lymphoma
Diagnostic Criteria
- Primarily extranodal
- Most common site is nose
- Nodes may be involved secondarily
- Necrosis nearly always present
- Vascular destruction may be seen
- Ulceration common
- Pseudoepitheliomatous hyperplasia may be seen
- Wide range of appearance from small to large cell
- Frequently mixed
- Inflammatory cells may be prominent
- Cytoplasm may be clear with azurophilic granules on Giemsa stained cytologic preparations
- CD56 positive
- Rare cases may lack CD56, but must then be EBV+, CD3+ and cytotoxic protein+
- EBV positive
- May be lacking in some extranasal, North American or Western European cases
- Note that the term "nasal type" originally applied only to lymphomas of this type that occurred in sites other than the nasal cavity; it now includes nasal and extra-nasal locations
Dita Gratzinger MD PhD
Yasodha Natkunam MD PhD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Initial posting : September 1, 2007
