Question: Are there any theories on what causes Cushing’s tumors? Is it hereditary?

Answer: In most patients, a Cushing’s tumor (pituitary or adrenal) is not hereditary. There is a rare form of hereditary pituitary tumors, which is part of the Multiple Endocrine Neoplasia Type 1 syndrome. In this circumstance, members of the affected family have an increased risk for developing tumors of the parathyroid gland (high blood calcium), a pituitary tumor and a pancreatic tumor. In 1 study of patients with pituitary tumors, only 4% had MEN Type 1.  Research has also shown that some macronodular bilateral adrenal hyperplasias can be hereditary.

The actual cause of pituitary tumor development is under intensive investigation in several laboratories throughout the country. It is thought that these benign tumors, including Cushing’s, arise from a mutation or change in the gene DNA and as a result, there is growth of a benign pituitary tumor. The specific gene mutation in pituitary dependent Cushing’s is not yet known. Similarly, the precise mutation in adrenal adenoma causing Cushing’s is also not yet known.

By Dr. Mary Lee Vance MD (Summer, 1999)