An 80-year-old woman was diagnosed with primary cutaneous B cell lymphoma. She had multifocal cutaneous tumors, but no nodal lymphadenopathy or bone marrow involvement. Histopathological examination of a biopsy specimen showed diffuse large B cell lymphoma without a bcl-2 expression. Complete resolution of hypercalcemia and disappearance of tumors were achieved with CHOP therapy, but a rapidly progressive skin lesion was observed soon after the completion of the therapy. The clinical manifestation of primary cutaneous diffuse large B cell lymphoma is diverse and the treatment strategy is not entirely clarified. This case represents another example of this rare lymphoma.