Strumal carcinoid

Comments:
Strumal carcinoid consists of mature thyroid tissue (left half of the image) in addition to insular or trabecular carcinoid (right half). In some cases, carcinoid cells are seen colonizing thyroid follicles. The thyroid component is immunoreactive for thyroglobulin and TTF-1.

Thyroid-type papillary microcarcinomas can develop in strumal carcinoids. About 50% of cases show other teratomatous elements. Some cases occur in the setting of MEN type 2a. In addition to the neuroendocrine markers, there is immunoreactivity for prostatic acid phosphatase. The patients can develop carcinoid syndrome and severe constipation (due to secretion of peptide YY).