Metastatic pancreatic neuroendocrine carcinoma causing Cushing's syndrome. ACTH secretion by metastases 3 years after resection of nonfunctioning primary cancer.

CONCLUSION

Following resection of a nonfunctioning neuroendocrine carcinoma of the pancreas, subsequent metastases, in the absence of a primary cancer (resected), developed the capacity to secrete ACTH and create the Cushing syndrome.

BACKGROUND

Although neuroendocrine carcinomas of the pancreas may produce one or more hormones and may switch secretion to a different hormone, no report is identified of a metastasis, in the absence of the primary tumor, developing de novo the capacity to secrete ACTH.

METHODS

A nonfunctioning islet cell carcinoma was resected and immunochemically stained for multiple hormones. Three years later hepatic metastases were partially resected and stained as before.

RESULTS

The primary cancer stained negative for ACTH and cortisol, positive for serotonin, and focally positive for gastrin. Three years later, after the development of a florid Cushing syndrome, the metastasis stained strongly for ACTH and negative for serotonin.