Sellar plasmacytoma: A rare intracranial presentation

Intracranial plasmacytomas are rare and diagnostically challenging manifestations of multiple myeloma (MM), often presenting with varied clinical symptoms. We report a 60-year-old female presenting with right abducens nerve palsy. Contrast-enhanced magnetic resonance imaging (MRI) of the brain showed a heterogeneous sellar and parasellar mass with clival and sphenoid sinus erosion. Serum protein electrophoresis showed a lambda light-chain spike and elevated beta-2-microglobulin. A diagnosis of MM with sellar plasmacytoma was made. The patient received a combination of radiotherapy and the monoclonal antibody daratumumab. She showed marked clinical and biochemical improvement at the three-month follow-up, with complete resolution of cranial nerve palsy. This case underscores the importance of early recognition and management in optimizing outcomes for intracranial plasmacytomas.