Detection of an Acth-Secreting Bronchial Carcinoid Tumour Eighteen Months After Adrenalectomy for Cushing's Syndrome

Abstract

A patient is described in whom an ACTH-producing bronchial carcinoid tumour was found eighteen months after bilateral adrenalectomy for Cushing's syndrome. A critical review is given of laboratory methods used in the differential diagnosis of ectopic Cushing's syndrome. Finally a course of action is suggested by which such unnecessary ablative surgery might be avoided.In the majority of cases the so-called ectopie Cushing's syndrome is caused by a highly malignant tumour, usually a pulmonary oat-cell carcinoma (O'Riordan et al. 1966), and can be diagnosed before the development of clinical signs of hyperadrenocorticism. The chance of a permanent cure by resection of such a tumour is however very small.

Ectopic Hormone Production by Non‐endocrine Tumours

“…ACTH (bronchial carcinoid, Vingerhoeds et al, 1971;Ratcliffe et al, 1972;thymoma, Liddle et al, 1965; medullary carcinoma of thyroid, Donahower et al, 1966); parathormone (PTH) (squamous cell lung carcinoma, Grimes et al, 1967, intrahepatic biliary carcinoma, Knill-Jones et al, 1970; luteinizing hormone (LH) and follicle stimulating hormone (FSH) (adenocarcinoma of lung, Faiman et al, 1967); and prolactin (carcinomas of lung and kidney, Turkington, 1971). This type of evidence does not, however, exclude the possibility that the tumour secretes a substance stimulating hormone release from the normal endocrine gland of origin (see 1 above).…”

Review the Biosynthesis of Hormones by Non-Endocrine Tumours-a Review

“…A fall in circulating hormone levels, or regression of clinical abnormalities, following removal of a tumour provides supportive evidence of ectopie production, but does not exclude the possibility that the tumour may, in some way, stimulate the appropriate endocrine gland rather than secrete the hormone itself. Evidence of this type has been well documented for many hormones such as parathyroid hormone (PTH) secretion by squamous cell lung carcinoma (Grimes, Fisher, Finn & Danowski, 1967), and by intrahepatic biliary tract carcinomas (Knill-Jones, Buckle, Parsons, Calne & Williams, 1970); LH and FSH by adenocarcinomas of the lung (Faiman, Colwell, Ryan, Hershman & Shields, 1967); prolactin secretion by carcinomas of kidney and lung (Turkington, 1971) and ACTH secretion by bronchial carcinoids (Vingerhoeds, Kinderen, Thijssen & Schwarz, 1971;Mason, Ratcliffe, Buckle & Mason, 1972), thymomas (Liddle, Givens, Nicholson & Island, 1965), and medullary carcinomas of the thyroid (Donahower, Schumacher & Hazard, 1966).…”