A case of occult ectopic adrenocorticotropic hormone-secreting tumor: diagnostic and management dilemmas.

OBJECTIVE

To report a case of ectopic adrenocorticotropic hormone (ACTH) syndrome in a patient whose tumor was not localized by radiographic or biochemical means and to discuss the difficulties inherent in this patient's care, illustrative of the challenges encountered by clinicians faced with similar cases.

METHODS

We describe the clinical presentation of our case and discuss its management.

RESULTS

A 49-year-old woman presented with symptoms and physical findings strongly suggestive of Cushing syndrome. Findings on biochemical evaluation were consistent with ectopic ACTH syndrome. Radiographic imaging did not clearly identify a discrete tumor. Bilateral inferior petrosal sinus sampling and whole-body selected venous sampling were unsuccessful in localizing the source of ACTH secretion. Surgical exploration was undertaken with use of intraoperative ultrasonography. Both a primary tumor and metastatic disease were identified, and the patient underwent distal pancreatectomy and splenectomy, as well as sequential bilateral adrenalectomy. The primary lesion was a neuroendocrine tumor that did not stain positive for ACTH. Chemotherapeutic agents were used to control bulky hepatic metastatic lesions until the patient's demise 2 1/2 years after her initial presentation.

CONCLUSION

This case illustrates the difficulties encountered in the assessment and management of a patient with ectopic ACTH syndrome when conventional methods of tumor localization fail to identify the source of hormone secretion.