Endocrine Abstracts

Introduction: Plasma cell neoplasms include a variety of clinicopathologic entities including; multiple myeloma, solitary plasmacytoma of bone and extramedullary plasmacytoma. Plasma cell neoplasms of the pituitary area are very rare, with only 19 cases in the literature. We report a rare case of multiple myeloma presenting with parasellar mass.

Case: A 44-year-old lady was admitted with sudden onset of diplopia and blurring of vision. She also mentioned that she had lost a stone in weight for about 3 months. Past medical history was unremarkable except hypertension, treated with calcium channel blockers. Physical examination was normal apart from left sided 6th cranial nerve palsy. Initial investigations showed normal full blood count, renal and liver functions, and coagulation screen. Chest-X-ray was also normal. CT head revealed a 19 mm×16 mm left cavernous sinus/suprasellar mass and multiple skull lytic lesions. A MRI of the brain showed a 15 mm mass infiltrating and destroying the left posterior clinoid process and extending medially where it infiltrated the left dorsum sellae and extends to the pituitary fossa itself. The pituitary hormonal profile, including prolactin, growth hormone, IGF1, LH, FSH, estradiol, TSH and cortisol, was unremarkable. The presence of skull lytic lesions raised the possibility of myeloma. Serum electrophoresis, urine for Bence Jones proteins, bone marrow aspirate and biopsy, confirmed diagnosis of light chain myeloma. She was treated with cyclophosphamide, thalidomide and dexamethasone; four weeks later, repeat MRI showed reduction of para-sellar mass with improvement of the 6th nerve palsy.

Comment: Plasma cell neoplasm may present with symptoms and signs indistinguishable from non-functioning pituitary adenoma, therefore it should be considered in the differential diagnosis of sellar and parasellar tumours. Atypical symptoms such as cranial nerve involvement and preservation of anterior pituitary function should raise the suspicion. If in doubt a biopsy is confirmatory.