Acidophil Stem Cell Pituitary Neuroendocrine Tumor

**Semantic type:** Neoplastic Process

**Definition:** An infrequent pituitary neuroendocrine tumor composed of cells showing immunoreactivity for prolactin and less often growth hormone. Electron microscopic studies reveal giant mitochondria, a finding not present in any other type of pituitary gland adenomas.

**Synonyms:** - ASCA - Acidophil Stem Cell Adenoma - Acidophil Stem Cell PitNET/Adenoma - Acidophil Stem Cell Pituitary Neuroendocrine Tumor/Adenoma