Endocrine Abstracts

Introduction: Malignant tumors, nevertheless, have been associated with extremely high circulating ACTH and cortisol levels, and short duration of symptoms of Cushing syndrome (CS) besides atypical clinical phenotype, when compared with pituitary-dependent Cushing. Identification of the source of ACTH can be challenging, as sometimes the primary lesion is not identified even after prolonged and repeated follow-up

Case report: A 33-year-old woman with a history of insulin-induced diabetes admitted to our department for suspicion of ACTH-dependent Cushing’s syndrome held in front of: a Cushing’s syndrome clinic, biological Cushing’s syndrome, CLU: 2894 μg/24 h, minute braking: negative, cortisolemia 32.1 μg/dl, ACTH: 232 ng/l, CT scan of the adrenal glands in favor of moderate adrenal hyperplasia. MRI Pituiray without anomaly, strong negative braking. an Octreoscan objectified the presence of two thyroid nodules of hypodense generation moderately fixing the radiotracer, measuring respectively 1.9×1.2 cm on the right and 1.5×1.1 cm on the left. The focus intensely fixes the retrotracheal radiotracer and the right paravertebral retrotracer. tumor markers are negative. the patient was operated on for anopathy: thyroid nodular dystrophy, reactive lymphadenitis, a review of the anopathy with iminohistochemistry is requested results in progress. the patient comes to our training 1 month post-operative, the patient reports a regular cycle return, the clinical examination shows a disappearance of purple stretch marks and bruises. Control octreoscan shows the absence of signs in favor of a neuroendocrine tumor at the pleuro-pulmonary, digestive or thyroid level.

Discussion: Most primary endocrine tumors responsible for Ectopic ACTH syndrome (EAS) are located in the chest. Among all ACTH-secreting thoracic tumors, the most common, in a modern endocrine patient recruitment, are welldifferentiated NETs located in the bronchi (formerly called ‘carcinoids’) and these account for 20% to 40% of all cases of EAS in recent series. They can recur, especially after initial resection without systematic lymphadenectomy. ‘Tumorlets’ or diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, a precursor to carcinoid tumors and tumorlets, represent a particular bronchial NET type, being small These are mainly located in the chest and can mimic lung metastases. Thymic NETs are also an important cause of EAS due to thoracic tumors accounting for 5% to 10% of EATs, depending on the series.

Conclusion: ACTH-dependent Cushing syndrome due to ectopic ACTH production most of times is difficult to manage. The identification of the source of ACTH may take many years until final diagnosis.