Endocrine Abstracts

Primary adrenal tumours are responsible for about 10% of cases of Cushing's syndrome. Adrenocortical carcinomas are rare with an incidence of 2 per million per year. Both adrenocortical adenomas and carcinomas occur more commonly in women.

A 46 year old previously fit woman presented with a short history of hirsutism, facial plethora, amenorrhoea, acne and progressive weight gain. Hypertension and glucose intolerance had been diagnosed recently. There was no history of headaches or visual disturbance.The patient was not on any steroid medication.

Cushing's syndrome was suspected and confirmed biochemically.24 hour urine free cortisol levels were high with loss of diurnal variation of cortisol secretion. High dose dexamethasone suppression test (2 mg every 6 hours for 2 days) was suggestive of primary adrenal disease. Serum testosterone was elevated more than twice the upper limit of normal at 7.2nmol/l (ref 0.5-2.6). Urinary catecholamine levels were normal.

The short presenting history and raised testosterone level was suggestive of a malignant adrenal tumour. Abdominal CT scan demonstrated a large left adrenal mass with central necrosis and no evidence of metastases. A large tumour was subsequently completely resected. Histology confirmed this to be an adrenal carcinoma. The patient is currently normotensive with normal glucose tolerance. There is no evidence of tumour recurrence.

High androgen levels in Cushing's syndrome are suggestive of malignant adrenal disease. Adrenal carcinomas secrete glucocorticoids and androgens autonomously and are not under hypothalamic-pituitary control. They present rapidly and have a progressive course. They have usually metastasised to the lungs and liver at diagnosis and the prognosis is universally poor. Mitotane, an isomer of the insecticide DDT is used as

adjunctive therapy to treat metastatic disease.