Chronic Lymphocytic Leukemia of B Cell and T Cell Prolymphocytic Leukemia

The hematological malignancy chronic lymphocytic leukemia (CLL) is the commonest form of leukemia in adult humans in the Western hemisphere, with more than 15,000 cases recognized annually every year. The specific skin infiltrates in patients with B cell CLL (B-CLL) are varied and include localized or generalized erythematous papules, plaques, nodules, and large tumors. CD1d expression is quite variable in the setting of CLL. In most instances it is expressed at lower levels compared to certain other lymphoproliferative disorders. Polymerase chain reaction studies performed on paraffin-embedded tissues using appropriate consensus primers show immunoglobulin heavy chain gene rearrangement. Although T cell prolymphocytic leukemia was formerly considered to be the T cell counterpart of typically insidious B-CLL, the aggressive clinical course that defines most cases prompted reclassification by the World Health Organization (WHO). Skin involvement is common in the course of T cell prolymphocytic leukemia.