Cutaneous infiltration by T-cell prolymphocytic leukemia in two adult patients.

Background: T-cell prolymphocytic leukemia (T-PLL) is a T-cell lymphoproliferative disorder that frequently involves the skin. The objective was to describe two cases of T-PLL with cutaneous involvement and to present a review of the literature concerning the clinical characteristics, differential diagnosis and treatment of these patients. Case reports: 1) 79 year-old man, with a previous diagnosis of T-PLL based on a laboratory incidental finding. He had been treated with alemtuzumab, but it had to be interrupted due to recurrent infections. After interrupting the treatment, the patient developed a symmetrical rash on his extremities. The skin biopsy demonstrated TPLL infiltration. 2) 28 year-old man that presented with asthenia and lymphocytosis. He also showed a purpuric rash on his trunk and facial erythema. Histopathology of the skin and bone marrow confirmed the diagnosis of T-PLL with cutaneous involvement.

Conclusions: T-cell prolymphocytic leukemia accounts for 2% of mature leukemias in adults. Skin involvement is reported in 20-50% of the patients. The characteristic features are facial involvement, purpuric lesions and symmetry of the rash, although there are atypical manifestations as well. Differential diagnosis includes other T-cell lymphoproliferative disorders with hematologic and skin involvement, such as Sézary syndrome. Patients with T-PLL may show cutaneous infiltration at the moment of debut or relapse of the disease. The skin is an accessible organ for taking samples to study and diagnose these patients.