Endocrine Abstracts

A 49-year-old male presenting with acute onset strabismus on left lateral gaze was admitted to the Endocrinology Department. The CT scan showed a 35×40×25 mm tumor mass, presumed to be a pituitary macroadenoma, in the sellar region which extended into the sphenoidal sinus, clivus, posterior ethmoidal cells, petrous part of the temporal bone and towards the nasopharynx. A MR scan of the head also revealed that the mass displaced the anterior pituitary gland and the infundibulum upwards. The MRI result was not typical for pituitary macroadenoma and raised the possibility of another tumour. A biopsy was performed and a specimen of the sphenoidal sinus mass was obtained. The histological examination revealed that the tumor was a moderately differentiated plasmacytoma with restriction to kappa light chains and a serum proteinogram showed a disturbance in the κ/λ ratio with a raise in the free κ light chains. A radiographic skeletal survey showed a suspect lesion of the 8^th thoracic vertebra. Endocrinological assessment revealed indirect hyperprolactinaemia, secondary hypothyroidism and insufficiency of the pituitary-gonadal axis. After beginning the treatment with bortezomib and dexamethasone as well as radiotherapy, the patient’s pituitary-adrenal axis also became insufficient. Plasmacytoma in the sellar region is very rare. There have been 33 cases reported in the literature insofar, but the number is even lower for cases where the sellar region was the first and/or only site of occurrence without prior diagnosis of multiple myeloma. The majority of sellar plasmacytomas described were diagnosed only after surgical treatment, whereas ours is the second case so far where the diagnosis was made prior to any surgical intervention in a patient without pre-existing multiple myeloma. It is also uncommon for plasmacytoma of the sellar region to present with a disturbance of the pituitary-peripheral axis, besides hyperprolactinaemia.