Harach H R
Histopathology. 1985 Feb;9(2):195-207. doi: 10.1111/j.1365-2559.1985.tb02435.x.
Mucoepidermoid carcinoma of the thyroid (MECT) has been recently recognized as a pathological entity. The origin of MECT is unknown but the morphology of this tumour closely resembles features seen in the ultimobranchial body (UB) vestiges. Recent studies in man have shown strong evidence that the so-called solid cell nests (SCN) of the thyroid may correspond to the human UB vestiges. To investigate whether these vestiges are the site of origin of this tumour a comparative study on SCN and MECT was undertaken. One hundred autopsied thyroids cut at 2-3 mm intervals were studied for the presence of SCN. Histochemical (H & E, Alcian blue-PAS, Mayer mucicarmine) and immunohistochemical studies (calcitonin, epidermal keratin) were performed in SCN and four cases of MECT. Sixty percent of thyroids were found to have SCN. They were mainly composed of epidermoid-like cells arranged in solid structures or lining cystic cavities, tubular and follicular structures. Solid clusters usually showed lumina containing PAS-positive and mucin-positive cell debris. Mucin stains also revealed mucinous cells placed around lumina filled by mucosubstances. Characteristic PAS-positive rounded bodies were found filling lumina as well as within some apical epidermoid-like cells, mucinous cells and cell debris. An obvious transition between these cells, cell debris and mucosubstances filling the lumina was noticed; suggesting degenerative changes undergone by the epidermoid-like cell. MECT basically presented all histological and histochemical features shown by SCN, furthermore, calcitonin containing cells were observed in 54% of SCN, while a metastatic MECT also showed scattered C cells within solid islands. The presence of epidermal keratin in all SCN and MECT, together with the previous findings, are strong evidence that MECT could originate in the SCN or human UB vestiges.
甲状腺黏液表皮样癌（MECT）最近被确认为一种病理实体。MECT的起源尚不清楚，但其肿瘤形态与终末鳃体（UB）遗迹的特征极为相似。近期对人类的研究有力地证明，甲状腺所谓的实性细胞巢（SCN）可能与人类UB遗迹相对应。为了探究这些遗迹是否为该肿瘤的起源部位，对SCN和MECT进行了一项对比研究。对100个间隔2 - 3毫米切开的尸检甲状腺进行了SCN检查。对SCN和4例MECT进行了组织化学（苏木精和伊红染色、阿尔辛蓝-过碘酸希夫染色、梅耶尔黏蛋白胭脂红染色）和免疫组织化学研究（降钙素、表皮角蛋白）。发现60%的甲状腺有SCN。它们主要由排列成实性结构或内衬囊腔、管状和滤泡状结构的表皮样细胞组成。实性细胞团通常显示含有PAS阳性和黏蛋白阳性细胞碎片的管腔。黏蛋白染色还显示黏液细胞位于充满黏液物质的管腔周围。发现特征性的PAS阳性圆形小体充满管腔以及一些顶端表皮样细胞、黏液细胞和细胞碎片内。注意到这些细胞、细胞碎片和充满管腔的黏液物质之间有明显的过渡，提示表皮样细胞发生了退行性变化。MECT基本上呈现了SCN所显示的所有组织学和组织化学特征，此外，54%的SCN中观察到含降钙素的细胞，而转移性MECT在实性细胞岛内也显示有散在的C细胞。所有SCN和MECT中均存在表皮角蛋白，结合先前的研究结果，有力地证明MECT可能起源于SCN或人类UB遗迹。
