Mature T- and NK-Cell Neoplasms

Mature T- and NK-cell lymphomas include over 30 entities in the current 2016 Revision of the World Health Organization classification. T- and NK-cell lymphomas are overall much less frequent than B-cell lymphomas. Some of these lymphomas are most commonly diagnosed in Asia and Central and South America (e.g., aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type) and are relatively rare in Western world. This group includes a number of primary cutaneous lymphomas. Clinical presentation of different lymphomas in this group varies widely, including some indolent entities (e.g., lymphomatoid papulosis) as well as aggressive neoplasms with poor prognosis (e.g., hepatosplenic T-cell lymphoma).