Division of Pathology, Sagamihara National Hospital, Minami-ku, Kanagawa, Japan.
Int J Gynecol Pathol. 2011 Jan;30(1):64-70. doi: 10.1097/PGP.0b013e3181efbe29.
Atypical polypoid adenomyoma (APA) is a relatively rare benign uterine tumor, histologically characterized by proliferation of irregular endometrioid glands accompanied by stromal cells of smooth muscle origin. As the epithelial components of APA usually show cytological atypia, a differential diagnosis between this tumor and endometrioid carcinoma invading myometrium is often difficult, especially in curettage material. This distinction is clinically very important to avoid unnecessary hysterectomy. However, only a few immunohistochemical studies of APA that differentiate it from malignancy have been published. Therefore, we have investigated the expression of several antigens in APA and compared them with those present in myoinvasive carcinoma. Six specimens of APA were studied, along with controls of endometrioid carcinoma invading myometrium. Antibodies to p53, Ki-67, CD10, and h-caldesmon reacted positively using immunohistochemistry. Variable positive expressions of p53 and Ki-67 were observed in both epithelial and stromal components of APA, and in myoinvasive endometrioid carcinoma. CD10 was negative or partially and weakly positive whereas h-caldesmon was completely negative in the stromal cells of all 6 specimens of APA. However, in the myometrium in which endometrioid carcinoma invaded, a fringe-like positive staining pattern was occasionally observed for CD10, whereas a diffuse positive signal was obtained for h-caldesmon. The results of this study indicate that immunohistochemically, p53, and Ki-67 are not reliable markers but that h-caldesmon is useful in distinguishing APA from myoinvasive endometrioid carcinoma. Further, our data suggest that the stromal cells of APA are mainly immature smooth muscle cells, and thus APA may be a mixed tumor.
非典型息肉状腺肌瘤（APA）是一种相对罕见的良性子宫肿瘤，组织学上的特征是不规则的子宫内膜样腺体增生，伴有平滑肌来源的间质细胞。由于 APA 的上皮成分通常表现出细胞学异型性，因此与浸润子宫肌层的子宫内膜样癌进行鉴别诊断通常很困难，尤其是在刮宫标本中。这种区别在临床上非常重要，可以避免不必要的子宫切除术。然而，仅有少数关于 APA 的免疫组织化学研究能够将其与恶性肿瘤区分开来。因此，我们研究了 APA 中几种抗原的表达，并将其与浸润性癌进行了比较。研究了 6 例 APA 标本，并与浸润性子宫内膜样癌的对照进行了比较。使用免疫组织化学方法，p53、Ki-67、CD10 和 h-caldesmon 抗体均呈阳性反应。在 APA 的上皮和间质成分以及浸润性子宫内膜样癌中，均观察到 p53 和 Ki-67 的可变阳性表达。CD10 在所有 6 例 APA 的间质细胞中均为阴性或部分和弱阳性，而 h-caldesmon 则完全阴性。然而，在子宫内膜样癌浸润的子宫肌层中，CD10 偶尔出现边缘阳性染色模式，而 h-caldesmon 则获得弥漫性阳性信号。本研究结果表明，免疫组织化学中，p53 和 Ki-67 不是可靠的标志物，但 h-caldesmon 有助于将 APA 与浸润性子宫内膜样癌区分开来。此外，我们的数据表明，APA 的间质细胞主要是未成熟的平滑肌细胞，因此 APA 可能是一种混合性肿瘤。
