PRIMARY CUTANEOUS EXTRAMEDULLARY PLASMACYTOMA SECRETING LAMBDA-IGG

An adult male was described, who developed a tumour on his left arm, w hich was diagnosed as a primary cutaneous extramedullary plasmacytoma after histopathological, electron microscopic and immunocytochemical s tudies. Further studies ruled out the presence of multiple myeloma, ex tramedullary plasmacytoma of another site, or paraproteinaemia/parapro teinuria. During a relapse of the tumour 2 1/2 years after initial tre atment, a new immunocytochemical study demonstrated that the tumour ce lls expressed monoclonal lambda IgG at the intracytoplasmic level, an unusual finding.