Endocrine Abstracts

It is well established that the majority of the immunohistochemically confirmed gonadotroph adenomas are hormonally silent, accounting almost 64% of all clinically nonfunctioning pituitary adenomas. Whereas clinically functioning gonadotroph adenomas (FGA) are very rare and the exact prevalence is not known. We present the case of a FGA in a premenopausal. A 31-year-old female presented in the ED with oligomenorrhea for 11 months, abdominal pain and distention over the preceding 6 months with gradually increased intensity. She had attained menarche at 12 years with regular menses until 12 months before presentation. She denied headaches and visual disturbances. Examination revealed distended abdomen and biochemistry showed high concentration of oestradiol (2718nmol/l) with FSH: 10IU and LH: <1.0IU. Prolactin was 835mIU/l while TSH, fT4, cortisol, IGF-1 and somatotropin were unremarkable. A transvaginal ultrasound scan showed significantly enlarged ovaries bilaterally with multiple cysts. Contrast enhanced pituitary MRI demonstrated a sellar-suprasellar macroadenoma (13x21x16mm), minimally abutting the adjacent left cavernous sinus without significant invasion and chiasmal compression. Subsequently, the patient had transsphenoidal surgery (TSS) with transient postoperative diabetes insipidus. Postoperatively, immunohistochemistry showed strong immunoreactivity with FSH and pan-α-subunit along with weaker focal staining for LH and strongly positive for SF1. Ki67 proliferation index was 1-2%. MRI imaging and hormone profile over the next 4 years following surgery continued to reveal radiological and biochemical remission. FGAs are a heterogenous group of rare neoplasms which in females manifest with ovarian hyperstimulation syndrome (OHSS), hyperoestrogenaemia and normal or mildly elevated FSH. Most of the reported FGAs in premenopausal women are macroadenomas, in keeping with our case. Long-term data on the outcome of patients with FGAs after surgery, with or without combined radiotherapy are very sparse. Our case provides useful evidence of sustained remission 4 years after TSS in a patient with a FGA treated in comprehensive multidisciplinary pituitary service.