Vol. 7, Issue 3, Part B (2024)

Plasmacytoma is a neoplastic proliferation of monoclonal plasma cells in bone or soft tissue, potentially indicating multiple myeloma. Solitary plasmacytoma is rare, with an incidence of 0.15/100,000, commonly affecting vertebrae and skull bones or the head and neck region. Etiology includes chronic stimulation, radiation, viral infections, and genetic factors. This case involves an 82-year-old male with a painless parietal swelling, revealing an osteolytic lesion upon imaging. Histopathology showed pleomorphic plasma cells, confirmed by CD138 positivity on immunohistochemistry, leading to a plasmacytoma diagnosis. Comprehensive diagnostics are crucial for accurate identification and treatment.