Ectopic Cushing syndrome from pulmonary carcinoid tumor

Case contributed by Dr Rajesh Annamalaisamy

Presentation

Severe depression, headaches, weakness and ? bipolar disorder.

Patient Data

Age: 40
Gender: Male

CT shows a small right middle lobe lung nodule and bilateral adrenal hyperplasia.

Nuclear medicine

Octerotide

Uptake in the right lung nodule. 

Case Discussion

Following CT, patient had serum cortisol and ACTH levels assessed. Cortisol was > 3000 and ACTH was 162. He also had mild diabetes, profound hypokalemia and hypocalcemia. MRI brain was normal. Octreotide scan confirmed uptake in the right lung nodule and a diagnosis of ectopic Cushing syndrome was made.

Following resection, the patient was completely relieved of his symptoms. Pathology confirmed a carcinoid tumor.

Unlike Cushing disease, with an 8:1 female to male preponderance, this syndrome is more common in men. Earlier it has been reported that ectopic secretion of ACTH is most often from small cell carcinomas of the lung. But, later reports indicate that bronchial carcinoid tumor is the single most common cause.

Other well documented cases included thymic carcinoid, medullary thyroid carcinoma, pheochromocytoma, medullary paraganglioma, pancreatic islet cell tumors, and tumors of the ovary, cervix and prostate. The Cushing syndrome due to ‘primary’ hepatic carcinoid is very rare.

Tumors are best localized with CT thorax/abdomen in >80% of cases. However, in case of failure to localize the ectopic source of ACTH secretion with one modality, multiple imaging techniques should be employed to identify the same. CT, MRI and octreotide scan/PET scan all may be required to localize the ectopic source of ACTH secretion.

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Case information

rID: 19559
Published: 24th Sep 2012
Last edited: 14th Aug 2019
System: Chest
Inclusion in quiz mode: Included