Primary extramedullary orbital plasmacytoma in a child.

We describe a rare case of extramedullary plasmacytoma of the orbit in an 11-year-old boy. Immunoperoxidase staining of the tissue was positive for IgG, kappa chain and negative for lambda chain. Serum and urine electrophoresis showed no M spike. Systemic examination and bone marrow aspirate failed to show generalised involvement. The tumour was completely excised and radiotherapy given postoperatively.