Endocrine Abstracts

Introduction: Multiple myeloma (MM) is a haematological disorder characterised by an aberrant rise in monoclonal paraprotein. Intrasellar plasmacytomas can be infrequent MM manifestations. They are challenging to diagnose and frequently mimic pituitary adenomas; however rarely present with pituitary apoplexy. We describe a patient with pituitary apoplexy-like symptoms, subsequently diagnosed with MM, whose intrasellar mass entirely resolved after chemotherapy.

Case report: A 54-year-old female presented with headache and visual disturbance to the emergency department. Her CT head showed a pituitary lesion with haemorrhage. She was managed as pituitary apoplexy, with IV Hydrocortisone at the presentation, followed by oral hydrocortisone replacement. Her MRI head identified a pituitary mass reported as a macroadenoma, distorting chiasm and optic nerves despite the normal visual fields assessment. Hypertension and renal impairment were noted with anaemia (Hb 72 g/l, creatinine 149 umol/l, and eGFR 35 mL/min/1.73 m2). Subsequently, MM screening revealed significantly high kappa free light chains (>6000 mg/l). Following a haematology review, she had a bone marrow biopsy that showed 80% plasma cells, and a whole-body MRI reported multiple lytic lesions consistent with MM. The pituitary MDT agreed this might be a pituitary plasmacytoma and suggested considering lumbar puncture, but the haematology MDT recommended reassessing after chemotherapy. Following the first cycle of Daratumumab-VTD (Dara-VTD), a contrast pituitary MRI revealed complete remission of the pituitary plasmacytoma. She completed four cycles of Dara-VTD with an excellent response to treatment and has completed autologous stem cell transplant under haematology care. She remains on a small dose of hydrocortisone replacement with otherwise normal pituitary function.

Discussion: Pituitary plasmacytomas can present with pituitary apoplexy. Despite their challenging diagnosis, they are usually responsive to chemotherapy treatment.