Abstract: Objective To investigate the clinical characteristics in an elderly patient with sellar multiple myeloma. Methods Clinical features, laboratory data and radiologic profile of an elderly patient with sellar multiple myeloma were collected. Results The patient was an 85-year-old male. The main clinical manifestations were fatigue, poor appetite and polyuria. Laboratory examinations showed a significant decrease in blood sodium, several anterior pituitary hormones and an increase in total protein, mass of pituitary lesion and concentration of prolactin. During etiological screening, it was found that the blood immunoglobulin G (IgG) level was significantly increased, the blood M protein was positive and the bone marrow smear showed myeloma cells accompanied by multiple osteolytic lesions in the bones of the whole body. Considering the diagnosis of multiple myeloma, the pituitary lesion was likely to be the extra-medullary involvement. Conclusions The intrasellar plasmacytoma is not common. The disease onset is insidious with clinical features and imaging findings lacking specificity. Therefore, diagnosis relies on biopsy which poses risks for elderly patients and increases diagnostic challenges leading to misdiagnosis.

Key words: multiple myeloma, sellar lesion, intrasellar plasmacytoma, elderly