Effective in vivo purging with rituximab and autologous peripheral blood stem cell transplantation in a woman with CD5 positive primary cutaneous diffuse large B-cell lymphoma.

Generalized subcutaneous tumors developed without any other sites of the disease in a Japanese woman. Skin biopsy revealed CD5(+) and CD20(+) atypical diffuse large cells infiltrating subcutaneous tissues. The diagnosis was CD5(+) primary cutaneous diffuse large B-cell lymphoma. Tumor-specific PCR showed the existence of malignant cells in the peripheral blood and bone marrow. After three cycles of chemotherapy, she was remained in partial remission. Peripheral blood stem cells (PBSC) were harvested after the fourth cycles of chemotherapy combined with rituximab for in vivo purging. The contamination of tumor cells in PBSC was negative with PCR. She then underwent autologous peripheral blood stem cell transplantation using purged PBSC and has remained in complete remission for the past 24 month.