Imaging Case: NK/T-Cell Lymphoma, Nasal Type.

Peripheral T-cell lymphomas are a group of heterogeneous disorders and according to WHO classification, are categorized into nodal and extranodal forms. NK/T-cell lymphoma, nasal type, is a subtype of extranodal peripheral T-cell lymphoma and commonly presents as a midfacial destructive lesion. This disorder is more prevalent in Asia and South America and has a strong association with Epstein Barr Virus infection. Invasion of vessel walls by lymphoid cells, which is known as angiocentricity, is characteristic of nasal type NK/T-cell lymphoma. The tumor cells express CD2 and CD56 antigens; but not CD3. The nasal cavity is the mostly frequently affected site. Other commonly affected sites include palate and upper airways. On cross sectional imaging, the nasal involvement is seen as a diffuse sheet-like mucosal thickening along the nasal turbinates and septum or as a destructive midline mass (Figs.1,2).