Ueo Tetsuya, Kashima Kenji, Daa Tsutomu, Kondo Yoshiyuki, Sasaki Atsushi, Yokoyama Shigeo
Department of Pathology, Faculty of Medicine, Oita University, Oita, Japan.
Pathobiology. 2005;72(5):269-78. doi: 10.1159/000089421.
Morules develop in several neoplasms and have been considered as a type of squamous metaplasia despite the absence of keratinization and intercellular bridges. The objective of this study was to clarify the pathological significance of morules and to distinguish morules from squamous metaplasia in colonic neoplasms. Ten cases of morule-associated colonic neoplasms (4 adenocarcinomas, 1 adenoma with carcinoma in situ, and 5 adenomas), and 3 cases of squamous metaplasia in colonic adenocarcinoma were examined morphologically and immunohistochemically. Morules were well-defined structures composed of small, oval to short-spindled cells with bland nuclei, and frequently associated with intranuclear inclusions that were positive for biotin and biotin-binding enzymes (pyruvic acid carboxylase and propionyl CoA carboxylase). On immunohistochemical examination, morules characteristically showed nuclear overexpression of beta-catenin, cyclin D1 and p63, low Ki-67 labeling index (<1%), cytoplasmic overexpression of CD10, and no expression of cytokeratin 20. These molecules were useful for the differentiation of morules. Furthermore, p63 and 34betaE12 positivities in morules suggested that they have a basal/stem cell phenotype. Thus, morules were morphologically and qualitatively different from squamous metaplasia. We consider that morules in colonic neoplasms are cell clusters with a basal/stem cell phenotype, and have less proliferative and less invasive potential than other cancer cells.
桑葚体可见于多种肿瘤，尽管缺乏角化和细胞间桥，但仍被认为是一种鳞状化生。本研究的目的是阐明桑葚体的病理意义，并在结肠肿瘤中区分桑葚体与鳞状化生。对10例与桑葚体相关的结肠肿瘤（4例腺癌、1例原位癌伴腺瘤和5例腺瘤）以及3例结肠腺癌中的鳞状化生病例进行了形态学和免疫组织化学检查。桑葚体是界限清楚的结构，由小的、椭圆形至短梭形细胞组成，细胞核温和，常伴有核内包涵体，这些包涵体对生物素及生物素结合酶（丙酮酸羧化酶和丙酰辅酶A羧化酶）呈阳性。免疫组织化学检查显示，桑葚体特征性地表现为β-连环蛋白、细胞周期蛋白D1和p63核过表达，Ki-67标记指数低（<1%），CD10胞质过表达，细胞角蛋白20无表达。这些分子有助于区分桑葚体。此外，桑葚体中p63和34βE12阳性提示它们具有基底/干细胞表型。因此，桑葚体在形态和性质上与鳞状化生不同。我们认为结肠肿瘤中的桑葚体是具有基底/干细胞表型的细胞簇，与其他癌细胞相比，其增殖和侵袭潜能较低。
