This type of lymphoma is not frequently seen in the western hemisphere. Clinically, with the exception of anaplastic large cell lymphoma, mature T- and NK-cell lymphomas are among the most aggressive of all hematopoietic neoplasms. Representative disease entities include mycosis fungoides, angioimmunoblastic T-cell lymphoma, hepatosplenic T-cell lymphoma, and anaplastic large cell lymphoma. The disease is mature T-cell and NK-cell non-Hodgkin lymphoma (MONDO_0000430). Also known as: PTCL, mature T-and NK-cell lymphoma, mature T-cell and NK-cell lymphoma, mature T-cell and NK-cell non-Hodgkin's lymphoma, mature T-cell lymphoma, mature T-cell non-Hodgkin's lymphoma, peripheral T-cell lymphoma.