Oka H, Kameya T, Sasano H, Aiba M, Kovacs K, Horvath E, Yokota Y, Kawano N, Yada K
Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan.
Virchows Arch. 1996 Mar;427(6):613-7. doi: 10.1007/BF00202893.
A pituitary tumour composed of well-differentiated corticotrophs and adrenocortical cells is reported. Sections of the tumour revealed a mixture of small round cells with amphophilic or basophilic periodic acid-Schiff (PAS)-positive cytoplasm and large spherical and oval cells with abundant, granular, partly vacuolated PAS-negative cytoplasm. The small cells contained type 1 cytokeratin-positive microfilaments, numerous 250-500 nm endocrine-type secretory granules immunoreactive for adenocorticotropic hormone (ACTH) and beta-lipotropin. The large cells possessed ample cytoplasm filled with abundant vesicular smooth endoplasmic reticulum, numerous mitochondria possessing tubulovesicular cristae and frequent dense bodies. They lacked the features of pituitary endocrine cells or folliculostellate cells and were found to contain a panel of steroidogenic dehydrogenases and hydroxylases. The tumour was classified as a choristoma, in which two distinct cells types, corticotrophs and adrenocortical cells, were mixed. We suggest that, under continued ACTH stimulation, umcommitted stem cells may differentiate into adrenocortical cells. Alternatively, the presence of adrenocortical cells may be the result of heterotopia.
报告了一例由分化良好的促肾上腺皮质激素细胞和肾上腺皮质细胞组成的垂体肿瘤。肿瘤切片显示，小圆形细胞混合存在，其胞质呈嗜双色性或嗜碱性，过碘酸希夫（PAS）染色呈阳性；还有大的球形和椭圆形细胞，其胞质丰富、呈颗粒状、部分呈空泡状，PAS染色呈阴性。小细胞含有细胞角蛋白1阳性微丝、大量250 - 500纳米的内分泌型分泌颗粒，这些颗粒对促肾上腺皮质激素（ACTH）和β-促脂素呈免疫反应阳性。大细胞拥有丰富的胞质，充满大量泡状滑面内质网、许多具有管状嵴的线粒体和频繁出现的致密体。它们缺乏垂体内分泌细胞或滤泡星形细胞的特征，且发现含有一组类固醇生成脱氢酶和羟化酶。该肿瘤被归类为错构瘤，其中促肾上腺皮质激素细胞和肾上腺皮质细胞这两种不同的细胞类型混合存在。我们认为，在持续的ACTH刺激下，未分化的干细胞可能分化为肾上腺皮质细胞。或者，肾上腺皮质细胞的存在可能是异位的结果。
