Department of Histopathology and Cytopathology, Cotman Centre, Norfolk and Norwich University Hospital, Colney Lane, Norwich, NR4 7UB, UK.
J Mol Histol. 2024 Nov 29;56(1):6. doi: 10.1007/s10735-024-10282-6.
An endometrioid carcinogenic pathway of the fallopian tube with possible potential precursors including type II SCOUTs (secretory cell outgrowths) and E-TIN (endometrioid tubal intraepithelial neoplasia) has been recently documented. We report an incidental focus of E-TIN identified in a hysterectomy specimen for Grade 1 endometrioid type endometrial carcinoma. The lesion was present at the fimbriated end of left fallopian tube involving 1 plica. It comprised crowded glandular proliferation with a pseudostratified columnar lining. The cells displayed elongated nuclei with no remarkable nuclear atypia.Immunohistochemistry showed patchy loss of PAX 2 expression with multifocal aberrant nuclear and cytoplasmic staining for B-catenin. p53 was wild-type and ER was positive.In view of the co-existing endometrioid type endometrial carcinoma, a possible metastatic spread to the fallopian tube was considered. However, morphologically no obvious nuclear atypia noted, and no associated inflammatory response or desmoplastic stromal reaction identified within the tubal lesion. And on immunostaining, the endometrial tumour was distinct from the tubal lesion. For instance, PTEN was negative/lost in the endometrial tumour but retained in the tubal lesion and B-catenin was membranous in the endometrial tumour but aberrant with multifocal nuclear and cytoplasmic overexpression in the tubal lesion. WT1 was negative in the endometrial tumour but positively expressed by the tubal lesion. All the above findings favoured the possibility of the tubal lesion as being independent of the endometrial primary. In conclusion, we describe an incidental B-catenin aberrant endometrioid type proliferation of the fallopian tube/E-TIN, to raise awareness of such lesions.
最近已经记录到输卵管子宫内膜样癌的致癌途径，可能的潜在前体包括 II 型 SCOUT（分泌细胞外生）和 E-TIN（子宫内膜样管状上皮内肿瘤）。我们报告了在因 1 级子宫内膜样型子宫内膜癌行子宫切除术标本中偶然发现的 E-TIN 病灶。病变位于左侧输卵管伞端，累及 1 个皱褶。它由密集的腺体增生组成，具有假复层柱状衬里。细胞显示出拉长的核，没有明显的核异型性。免疫组化显示 PAX 2 表达呈斑片状缺失，B-连环蛋白核和细胞质呈多灶性异常染色。p53 为野生型，ER 阳性。鉴于同时存在子宫内膜样型子宫内膜癌，考虑可能发生转移至输卵管。然而，在输卵管病变中未观察到明显的核异型性，也未发现伴发的炎症反应或促结缔组织反应。免疫组化染色显示，子宫内膜肿瘤与输卵管病变不同。例如，PTEN 在子宫内膜肿瘤中为阴性/缺失，但在输卵管病变中保留；B-连环蛋白在子宫内膜肿瘤中呈膜性，但在输卵管病变中呈多灶性核和细胞质过度表达。WT1 在子宫内膜肿瘤中为阴性，但在输卵管病变中阳性表达。所有这些发现都支持输卵管病变与子宫内膜原发性无关的可能性。总之，我们描述了一种偶然的输卵管 B-连环蛋白异常子宫内膜样增生/E-TIN，以提高对这些病变的认识。
