Plasmacytoma is a descriptive term applied to tumours consisting of plasma cells. International Myeloma Working Group has described three types, solitary, extramedullary and multiple plasmacytoma. Solitary is involvement of a single bone, extramedullary is a localized collection of plasma cells in the soft tissue at an extraskeletal site such as orbit, whereas multiple involves many bones. They all lack systemic involvement. When there is a systemic plasma cell disorder, it is called multiple myeloma. The incidence of plasmacytoma in the orbits is very rare, and rarer still is an orbital mass as a presenting feature in multiple myeloma.
- 3.Sharma A, Kaushal M, Chaturvedi NK, Yadav R. Cytodiagnosis of multiple myeloma presenting as orbital involvement: a case report. Cyto J. 2006;10:3–19.Google Scholar