Endocrine Abstracts

Ectopic ACTH syndrome (EAS) occurs in around 10% of all cases with ACTH-dependent hypercortisolism. The mean age of clinical presentation varies from 45 to 50 years, and most of them caused by intrathoracic neoplasm, and recognition of the disorder may be delay. Subsequently, it may be difficult to locate the ACTH source and manage the patients’ hypercortisolism. We present our patients with EAS from 2000 to 2007. Four patients, aged 15–43 years, two females and two males included in the study. Symptoms duration lasted from 5 months to 4 years. All patients presented clinical signs of hypercortisolism with intense weakness due to proximal myopathy, 3 presented arterial hypertension, 1 presented poor controlled diabetes mellitus for 8 months, none of them presented hyperpigmentation, and two patients presented a mild psycotic picture. Hypokalemia was present in 2 cases (<3 mEq/l), all of them presented absence of cortisol circadian rhythm. Considering the upper limit of normal values for the assay, plasma ACTH levels were within normal range in 3 and slightly high in one. Three had osteoporosis and fracture. None of them did respond to 8-mg 2-d high-dose dexamethasone suppression test. Chest X-ray and CT localized the ACTH-secreting tumor in only one patient, and diagnosis proved by biyopsy. All imaging modalities (CT/MRI/ octreotide scintigraphy) were negative in the others. Two patients did not respond to CRH, and whereas one of these patients and another one did not showed a central-to-peripheral ACTH gradient on IPSS. Tumor markers, such as calcitonin, gastrin, CEA, and 5-HIAA were also negative in all patients. One patient had curative surgery, and three patients underwent bilateral adrenalectomy for control hypercortisolism. Subsequent imaging with CT/MRI.

Octreotide scintigraphy finally pointed to the presence of these tumors (2 pulmonary ACTH-secreting tumor, and one pancreatic neuroendocrine tumor) from 4 months up to 7 year later. One out of three are alive. Although initial failed localization is common, survival is good among the patients with pulmonary ACTH-secreting tumors.