Acidophil stem cell adenoma of the human pituitary: Clinicopathologic analysis of 15 cases

Abstract

In material of 347 surgically removed pituitary adenomas, 15 tumors (4.3%) were diagnosed as acidophil stem cell adenomas. These are immature neoplasms, assumed to derive from the common progenitor of growth hormone and prolactin cells, and usually containing both hormones by the immunoperoxidase technique. Clinically, they are regularly associated with hyperprolactinemia. Some patients may exhibit physical stigmata of acromegaly without biochemical evidence of the disease ("fugitive acromegaly"). The entity is also characterized by (1) relatively short clinical history; (2) large (grade III--IV), locally invasive adenoma, and (3) relatively low hormonal activity. By electron microscopy, these tumors are unicellular with immature cytoplasm, exhibiting some features of adenomatous growth hormone and prolactin with immature cytoplasm, exhibiting some features of adenomatous growth hormone and prolactin cells and frequently mitochondrial abnormalities as well. They are more aggressive than the well-differentiated adenomas of the "acidophil" cell line--a fact to be considered in postoperative management.

Growth hormone-secreting adenomas: pathology and cell biology

“…28 Three morphological tumor types that cosecrete GH and PRL can be identified as follows: the mixed GH cell/PRL cell adenoma, the mammosomatotroph cell adenoma, and the acidophilic stem cell adenoma. 12,24,26,28,31 Mixed GH cell/PRL cell adenomas and mammosomatotroph cell adenomas present clinically with acromegaly and mild hyperprolactinemia; on the other hand, patients with acidophilic stem cell adenoma present with hyperprolactinemia and only rarely with acromegaly. In our experience, these mixed tumors behave more aggressively than any pure GH-secreting adenomas with a lower surgical cure rate.…”

“…28,44 Unlike the 2 subtypes previously discussed, most of the patients present with symptoms of hyperprolactinemia; acromegaly is uncommon. 26 The majority of the tumors are rapidly growing macroadenomas with invasive features, a distinct behavior pattern of ordinary prolactinomas; therefore, the diagnosis of such adenomas is of clinical relevance. Histologically, acidophilic stem cell adenomas are chromophobic with focal oncocytic changes of the cytoplasm.…”

“…Electron microscopy is necessary for precise identification of this adenoma. 25,26 They are composed of a single population of immature cells exhibiting features reminiscent of both SGGH cells and PRL cells. Oncocytic change with the presence giant mitochondria is characteristic of these adenomas.…”

Secretory granules of pituitary adenomas: quantitative study of hormonal antigenicity

“…This study is based on 5 growth hormome (GH)-secreting adenomas (cases 1-5), 5 prolactin (PRL)-secreting adenomas (cases 6-10) and 8 clinically non-functioning (CN-F) adenomas (cases [11][12][13][14][15][16][17][18] obtained at surgery. Preoperative serum hormonal levels of these 18 cases, as determined by radioimmunoassay, are shown in Table 1.…”

MANAGEMENT OF ENDOCRINE DISEASE: Clinicopathological classification and molecular markers of pituitary tumours for personalized therapeutic strategies

“…We therefore propose renaming such 'silent' tumours as 'ACTH tumour without signs of Cushing's', similar to the renaming of 'silent' GH tumours (28) as 'GH adenoma without acromegaly' (29). Acidophilic stem cell adenomas (25,30) are either GH-PRL or PRL tumours with giant and dilated mitochondria. It seemed necessary to us to provide these precisions to clarify the present day terminology, because some of these subtypes, i.e.…”