Primary cutaneous plasmacytoma:: a clinicopathological study of two cases with a long-term follow-up and review of the literature

Background: Primary cutaneous plasmacytoma (PCP) is a rare type of cutaneous B-cell lymphoma arising primarily in the skin and derived from clonally expanded plasma cells with a various degrees of maturation and atypia. The disease is rare with only 30 cases reported so far. Methods: Two cases of PCP with long-term follow-up of 17 and 15 years are presented. Results and conclusions: Both patients were men with nodular lesions on the face. Histologically, the lesions were composed, predominantly of variably maturated plasma cells with monotypic expression of immunoglobulin (Ig) lambda chains. Polymerase chain reaction for IgH genes did not reveal clonal rearrangement. Our cases are discussed in the context of previously reported cases of PCP with a long-term follow-up. We also include a review of all cases of PCP with known tumor progression earlier in the course of the disease (local relapse or visceral spread) to determine the clinical course of this primary cutaneous lymphoma.