PRIMARY CUTANEOUS PLASMACYTOMA - REPORT OF 2 CASES AND REVIEW OF THE LITERATURE

Primary cutaneous plasmacytomas are very rare. In this report, we desc ribe two such cases and review the literature on this entity. Both pat ients presented with a slowly growing, painless, and solitary mass on the chest wall. Histologically, one case was composed of mature-lookin g plasma cells, while the other was composed of immature and anaplasti c plasma cells, infiltrating the dermis. The epidermis was spared. Kap pa light-chain restriction was demonstrated by immunohistochemical tec hniques in both cases. There was no evidence of marrow disease even on repeated marrow biopsies, although extracutaneous lesions were detect ed in one patient. One remained in complete remission 6 years followin g local irradiation. The other patient was treated with local irradiat ion and systemic chemotherapy, with a complete response, but this was followed by multiple cutaneous recurrences and further remissions by t reatment with cytotoxic agents. The present cases and those reported i n the literature illustrate well the variable clinical course of prima ry cutaneous plasmacytoma. Although cure can apparently be achieved in some patients by local radiation therapy, more than half of the cases relapse or progress to myelomatosis. The disease-related mortality is at least 40%. Thus cutaneous plasmacytoma appears to be more aggressi ve than noncutaneous extramedullary plasmacytomas and should be separa tely categorized from them in future studies.