Plasmacytoma of the mandible: A diagnostic conundrum

Plasma cell dyscrasias are neoplastic proliferation of monoclonal plasma cells that encompass a wide range of entities. Plasmacytoma may present as one of two distinct clinical entities: Multiple myeloma and solitary plasmacytoma. The incidence of solitary plasmacytoma is 2-5% among all plasma cell neoplasms and it commonly involves long bones and vertebrae. Its occurrence in the jaw is extremely rare and only 4.4% are seen in mandible. Clinically, plasmacytoma of mandible presents as pain, tooth migration, hard and soft tissue swelling or pathological fracture. Radiologically, it presents as unilocular or multilocular lesion mimicking odontogenic tumour creating a diagnostic dilemma. We report a series of 3 cases of plasmacytoma of the mandible with comprehensive details of clinico-radiological, histological, immunohistochemistry findings and treatment with a review of the literature. These three cases were clinically mistaken for Ameloblastoma, Odontogenic tumour and Oral cancer respectively. There was one case of Solitary Plasmacytoma and two cases on further workup proved to be multiple myeloma. All these cases were confirmed by immunohistochemistry. Plasmacytoma of mandible is very rare. It is usually mistaken for other common mandibular lesions and oral cancers. Every attempt must be made to diagnose them precisely as management is quite specific. To best of our knowledge, this is the first series of plasmacytoma of the mandible in the Indian literature.