Amyloid in polypeptide hormone-producing tumors.

The hormone content of 72 endocrine tumors was determined by immunofluorescence and their amyloid content was investigated. Seventeen of the 72 tumors contained amyloid. Amyloid was frequently found in tumors producing calcitonin, insulin, or growth hormone, but was rarely found in other tumors. Thus, there is a relationship between the occurrence of amyloid in an endocrine tumor and the type of hormone it produces. The reason for this is not known, but there is evidence that the amyloid fibrils contain proteins related to the hormone produced by the tumors.