A case of secondary syphilis simulating plasmocytoma

: A clinically unclear case is described of stomatitis with a long duration in a male of 28. Exfoliations in the region of the mouth angle were observed resembling pemphigus vegetans. Biopsy examination revealed a thick plasma cell infiltration which was considered to be an extramedullary plasmacytoma. However, a polyclonal composition of plasmacytes was found immunomorphologically producing immunoglobulins A, M and G with predominant production of IgG. This allowed rejection of neoplastic nature of the infiltrate, confirming its inflammatory origin and specific character. Serological tests (Wassermann, immunofluorescence test, in vitro immobilization test) confirmed the diagnosis of secondary recurring syphilis. Differential diagnosis of plasma-cell syphilid of skin and mucosal extramedullary plasmacytoma is under discussion.