Tahir Maryam, Samankan Shabnam, Huang Marilyn, Pinto Andre
Int J Gynecol Pathol. 2023 Nov 1;42(6):576-581. doi: 10.1097/PGP.0000000000000931. Epub 2023 Aug 10.
Squamous morular metaplasia is closely associated with endometrioid proliferative lesions such as endometrial intraepithelial neoplasia, whereas endometrioid adenocarcinoma may also demonstrate squamous differentiation (morular or nonmorular). Alpha-methylacyl-CoA racemase (AMACR; P504s) is an immunohistochemistry marker expressed in many tumors, including prostate adenocarcinoma, renal cell carcinoma, and in a subset of gynecologic carcinomas, predominantly of clear cell histology. In small biopsy samples, the distinction between cervical high-grade squamous intraepithelial lesions (HSILs) involving endocervical glands from endometrioid squamous proliferations can be challenging, given their anatomic vicinity and some degree of morphologic overlap. Following the observation of AMACR positivity by immunohistochemistry within squamous morules in an index case, 35 endometrial samples containing squamous morular metaplasia (25) and nonmorular squamous metaplasia (10), and 32 cases of cervical HSIL involving endocervical glands were stained with AMACR. The endometrial cohort consisted of 2 benign anovulatory endometrium, 7 endometrial polyps, 7 endometrial intraepithelial neoplasia, 4 atypical polypoid adenomyomas, and 15 endometrioid adenocarcinomas. Positive cases were scored as diffuse (≥50%) or focal (<50%). AMACR staining was present in 96.7% of endometrial squamous lesions, including 14 (93.3%) of endometrioid carcinomas, and in all cases of endometrial intraepithelial neoplasia, endometrial polyps, atypical polypoid adenomyomas, and anovulatory endometrium with squamous morular metaplasia or nonmorular squamous metaplasia. In comparison, only 2 cases (5.8%) of cervical HSIL demonstrated positivity for AMACR. In conclusion, AMACR can reliably differentiate the cervical versus endometrial origin of squamous lesions in small biopsy specimens.
鳞状桑葚样化生与子宫内膜样增生性病变密切相关，如子宫内膜上皮内瘤变，而子宫内膜样腺癌也可能表现出鳞状分化（桑葚样或非桑葚样）。α-甲基酰基辅酶A消旋酶（AMACR；P504s）是一种免疫组织化学标志物，在许多肿瘤中表达，包括前列腺腺癌、肾细胞癌，以及一部分妇科癌症，主要是透明细胞组织学类型。在小活检样本中，区分累及宫颈管腺体的宫颈高级别鳞状上皮内病变（HSIL）和子宫内膜样鳞状增生具有挑战性，因为它们在解剖位置上相邻且存在一定程度的形态学重叠。在一例索引病例中通过免疫组织化学观察到鳞状桑葚体内AMACR呈阳性后，对35例含有鳞状桑葚样化生（25例）和非桑葚样鳞状化生（10例）的子宫内膜样本，以及32例累及宫颈管腺体的宫颈HSIL病例进行了AMACR染色。子宫内膜样本队列包括2例良性无排卵性子宫内膜、7例子宫内膜息肉、7例子宫内膜上皮内瘤变、4例非典型息肉样腺肌瘤和15例子宫内膜样腺癌。阳性病例按弥漫性（≥50%）或局灶性（<50%）评分。AMACR染色见于96.7%的子宫内膜鳞状病变，包括14例（93.3%）子宫内膜样腺癌，以及所有子宫内膜上皮内瘤变、子宫内膜息肉、非典型息肉样腺肌瘤和伴有鳞状桑葚样化生或非桑葚样鳞状化生的无排卵性子宫内膜病例。相比之下，仅2例（5.8%）宫颈HSIL病例AMACR呈阳性。总之，AMACR能够可靠地区分小活检标本中鳞状病变的宫颈来源与子宫内膜来源。
