A rare usually aggressive subtype of cutaneous T-cell lymphoma with characteristics of infiltration of the epidermis, dermis or subcutaneous tissue by a clonal population of mature, gamma/delta positive cytotoxic T-cells. Typically it presents with ulcerating plaques on the skin of the extremities, however, frequent involvement of mucosal and extranodal sites (such as the nasal cavity, gastrointestinal tract or lungs) is also observed. Infiltration of lymph nodes, spleen and bone marrow is uncommon and resistance to multilineage chemotherapy is reported. [from
SNOMEDCT_US]