Evolution of a terminal deoxynucleotidyl transferase-positive lymphoma from a chronic T cell lymphocytosis.

A 56-yr-old Caucasian man presented with a generalised scaly rash and a peripheral blood lymphocytosis of 5.6 X 10(9)/l. 5 yr later he developed cutaneous nodules, lymphadenopathy and hepatosplenomegaly. Cells with convoluted nuclei and prominent nucleoli were seen in the peripheral blood. He underwent splenectomy and received intensive chemotherapy but died 6 months later with CNS infiltration. At presentation the peripheral blood lymphocytes were E-ve, UCHT1 + ve, and OKT8 + ve. Following transformation, cells in blood, spleen and CSF were E-ve, OKT11 + ve, DR + ve and Tdt + ve. A proportion of these cells had a Sézary-like appearance at E/M. The splenic cells showed functional suppressor activity. This is the first reported case of the evolution of a Tdt + ve lymphoma from a post-thymic T cell lymphocytosis.