LBMON141 Macroorchidism In A Patient With A Functional Gonadotroph Macroadenoma

Abstract

Abstract Background Functioning gonadotroph adenomas (FGAs) are rare, since most pituitary adenomas of gonadotroph origin are clinically silent or non-functioning. FGAs produce hormones that are adequate to result in clinical syndromes. Clinical case We describe a 38-year-old male who presented with pressure effects from a sellar mass manifesting as persistent and progressive headache. He also complained of swelling of the feet, excessive sweating and coarsening of facial features as well as increased libido. The patient also reported symptoms consistent with obstructive sleep apnoea. His shoe size remained the same and had no features of acromegaly. His visual fields appeared intact on informal assessment. He appeared well virilised and had bilateral macroorchidism, with both testes markedly larger than the largest measurement on the orchidometer (25ml). He was found to have elevated follicle stimulating hormone (FSH) 26.7 to 38.4 IU/L [1.3 -19.3] and testosterone levels from 28.1 to 44.3 nmol/L [6.1 - 27.1] with luteinising hormone (LH) levels being either inappropriately non-suppressed or high, 5.7 - 12.3 IU/L [1.2 - 8.6]. He also had erythrocytosis [Hb 19.5 to 21.7 g/dL (14.3 -18.3) and macroorchidism, owing to high gonadotropin levels. The rest of his pituitary axis appeared intact, including TFT, cortisol levels, and IGF-1, were all within normal limits. Although histology of the pituitary adenoma could not be obtained as the patient declined surgery, clinical and biochemical findings were supportive of FGA diagnosis. Conclusions FGAs are rare, can have none or subtle clinical features, and often present late with mass effects. Functional gonadotroph adenoma should be suspected in a patient with a sellar mass, with high or non-suppressed gonadotropins in the presence of elevated gonadal steroids. Clinical features such as macroorchidism and polycythaemia may be easily missed or misinterpreted. Surgical removal should be the therapy of choice, and if successful can lead to reversal of the biochemical and clinical abnormalities. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.