Endocrine Abstracts

Adrenocortical carcinoma is extremely rare and accounts for 0.05–2% of all malignant neoplasms with an estimated incidence of 0.5–2% per million people per year. Feminising adrenal carcinoma is even rarer. We submit such a rare case presenting with gynaecomastia.

A 50 year old man presented with a year history of increasing bilateral gynaecomastia. He had no problems with his sexual function. Initial investigations by the GP showed low testosterone (4.8 nmol/l) with undetectable LH and FSH, TSH 2.2 mU/l, FT₄ 15 pmol/l, prolactin 131 & random cortisol 293. Renal function and liver enzymes were normal. It was initially thought that he had secondary hypogonadism but his 17 ß-oestradiol level was elevated at 332 pmol/l (0–130). α-fetoprotein and ß-hCG were normal. Whilst awaiting further review, he went to see his GP complaining of right flank pain. An ultrasound scan showed a large mass in the right flank suggestive of a renal cell carcinoma. A CT scan suggested that the mass was more likely to be of adrenal origin. Further investigations showed normal 24 hour urinary catecholamines, androstenedione level>34 nmol/l (1.0–10.8) and DHEAS 24 nmol/l (2.2–15.7). After a 48 h low dose dexamethasone suppression test, cortisol suppressed to 83 nmol/l, and androstenedione to 5.3 nmol/l but DHEAS showed minimal suppression at 20 nmol/l suggesting a degree of autonomous cortisol secretion by the lesion but demonstrating dexamethasone suppressibility of the markedly elevated androstenedione level.

He proceeded to laparotomy and a 1.2 kg adrenal tumour was removed, measuring 190×110×120 mm. The histology confirmed adrenocortical carcinoma. Androstenedione, DHEAS and 17 ß-oestradiol levels returned to normal post-surgery with improvement of his gynaecomastia. At his last review 2 years after his surgery his hormonal profile was normal with no evidence of recurrence of his tumour. This case illustrates the importance of considering an oestrogen-secreting adrenal tumour in cases of gynaecomastia with suppressed gonadotrophins and low testosterone.