Primary cutaneous anaplastic large cell lymphoma with fatal leukemic outcome in association with CLA and CCR4-negative conversion

A 70-year-old Japanese male presented with a 1-year history of skin tumors, which were diagnosed as primary cutaneous anaplastic large cell lymphoma (ALCL) because of the CD3low+, CD4+, CD25+, CD30+, CD45RO+, CD71+, HLA-DR+, CD8−, CD56−, and NPM/ALK− phenotype and monoclonal T-cell receptor-rearranged property of tumor cells as well as the absence of systemic involvement. At this time, the tumor cell was positive for cutaneous lymphocyte–associated antigen (CLA) and TH2 chemokine receptor CCR4. The eruption had repeatedly appeared and spontaneously regressed or regressed by virtue of several therapeutic modalities, including radiotherapy, interferon-α and chemotherapy, until the tumor cell invaded the gastric mucosa and spread to the peripheral blood 5 years later. Upon progression to the fatal leukemic change, the skin lesions inversely disappeared. Flow cytometric monitoring of the phenotype of peripheral blood and skin-infiltrating lymphocytes disclosed that the expression of CLA and CCR4 on the tumor cells was converted from positive to negative in association with the leukemic change. The altered expression of skin-homing receptors might change its clinical behavior.