Extramedullary plasmacytoma of the orbit: A rare case

Solitary orbital plasma cell neoplasm in the absence of multiple myeloma is very rare. We present here a case report of extramedullary plasmacytoma of the right orbital soft tissue in a 50-year-old Indian woman whose thorough diagnostic workup was negative for multiple myeloma. The patient presented with gradually increasing proptosis, swelling, and visual disturbances of the right eye for past one and half years. Computed tomography (CT) scan of the orbit revealed lobulated, mildly enhancing soft tissue lesion in the supero-lateral aspect of right orbit without intracranial extension. Pathological report revealed a plasma cell neoplasm and immunohistochemistry was positive for CD138, CD20, CD 79a, PAX-5. Complete skeletal survey and bone marrow examination report were normal. So, normal skeletal survey, absence of bone marrow involvement, absence of Bence-Jones protein, no anemia, no hypercalcemia, no renal disease, normal level of immunoglobulins all exclude the diagnosis of multiple myeloma. Since the visual acuity of the patient is well-preserved, so we have planned to treat her with local radiotherapy alone with 50 Gy over 5 weeks.