Endocrine Abstracts

A 57 year old man presented with a 2 year history of erectile dysfunction and loss of libido. He was able to achieve erections but could not maintain them for intercourse. This was causing considerable strain on his marital life. He also complained of lethargy and general fatigue. His past medical history included diet-controlled type 2 diabetes and hypertension. He was an ex-smoker with a 40 pack year history and drank socially. He was an office worker. He had 3 grown up children. There was no history of illicit drug, opiate, steroid or over the counter medication use. Serum testosterone checked at his GP was 5.3 nmol/l, which prompted endocrinology referral. On examination, his BP and CBG were normal. He was overweight (BMI 28) with central obesity. He had a post-pubertal voice, a full beard and normal male pattern hair development. There was no gynaecomastia, goitre, or other peripheral stigmata of endocrinopathy. He had a normal adult-sized penis. Both testes were palpated in the scrotum and testicular volume was 15 ml bilaterally. Baseline bloods showed a normocytic anaemia with Hb 121, normal PSA, renal and liver function, and HbA1c 51 mmol/mol. Endocrine blood panel done at 9 am and in a fasting state showed a low serum testosterone of 5.7 nmol/l, with normal SHBG and inappropriately normal gonadotrophins (LH 8.3 IU/l and FSH 9.0 IU/l). The rest of the pituitary profile was normal. A biochemical diagnosis of central hypogonadism was secured. MRI pituitary was the next logical step and showed a non-enhancing T1 hyperintense focus in the anterior pituitary gland on sagittal sequence, consistent with an intrasellar Rathke’s cleft cyst with proteinaceous content. The diagnosis was therefore central hypogonadism due to Rathke’s cleft cyst. Pituitary MDT recommended an observational approach with serial pituitary imaging. Testosterone replacement therapy in the form of transdermal gel was opted by the patient. Tostran 2% gel 20 mg once daily was started and the dose gradually uptitrated every 3 weeks, aiming for testosterone in the mid normal range. Symptomatic benefit and target testosterone level were achieved with a Tostran 2% gel dose of 50 mg OD. PSA and haematocrit monitored every 3-6 months initially remained normal. Investigation for anaemia showed iron deficiency, which was treated with iron supplements. At the 1 year follow up, the patient was fully satisfied with his sexual function, energy levels, vitality and mental well being.