Combined FSH and LH secreting pituitary adenoma in a young fertile woman without primary gonadal failure.

A 28 year old fertile woman presented with a history of amenorrhoea and galactorrhoea, and an enlarged pituitary fossa. Serum FSH and LH were repeatedly elevated both basally (32 and 44 mIU/ml) and after LRH (peak values, 108 and 420 mIU/ml). One mg of oestradiol (E2) benzoate im daily for 5 days failed to lower basal or LRH-stimulated serum gonadotrophins. Serum E2 was 170 pg/ml, basal serum prolactin (Prl) was 30 ng/ml and responded briskly to TRH (peak value 103 ng/ml). An 0.8 X 0.8 cm tumour was selectively excised by transsphenoidal surgery. Menses reappeared soon afterwards accompanied by normalization of serum FSH and LH plus biochemical evidence of ovulation. Specific immunostaining of tumoural cells was achieved with either FSH or LH antiserum, and adequate suppression of staining was obtained after preabsorbing each antiserum with and excess of its respective antigen. Our patient appears to be the first documented female with a combined FSH and LH producing pituitary tumour and no prior evidence of primary gonadal failure.