Endocrine Abstracts

Adrenal incidentalomas are increasingly recognised with the use of abdominal imaging with prevalence ranging from 0.35-0.45%. The vast majority of these are benign adrenocortical adenomas. Increasingly, subclinical hypercortisolism is recognised in such cases.
We describe a case of a 34-year-old asymptomatic primigravida with chance recognition of an adrenal mass during an obstetric ultrasound. Biochemical testing revealed consistently normal urinary catecholamine and elevated urinary cortisol excretion suggesting subclinical hypercortisolism. MRI of abdomen confirmed a 5cm right adrenal mass.
In view of the tumor size and functional status, laproscopic right adrenalectomy was performed in the second trimester of pregnancy with no intra or postoperative complications. Histology surprisingly showed evidence of pheochromocytoma. The patient since required corticosteroid replacement for 4 years before full recovery of her contralateral adrenal function.
The prevalence of pheochromocytomas among patients with an incidental adrenal mass differs considerably in various series (0-11%) and occurs approximately once in every 50,000 pregnancies. They represent a potentially lethal situation, and in pregnancy, are associated with significant maternal and foetal compromise.
Our patient was unique in that her adrenal tumour behaved biochemically like a Cushing's syndrome while histologically turned out to be a pheochromocytoma. The following scenarios can explain the combination of pheochromocytoma and cortisol hypersecretion; 1. Ectopic ACTH secretion by pheochromocytomas, 2. Cortisol producing adenoma associated with adrenomedullary hyperplasia, 3. In vitro corticosteroid formation by benign pheochromocytomas and 4. Combined cortical and medullary tumours.