由于形态与更常见的实体重叠，各种不常见的恶性子宫内膜肿瘤的诊断可能具有挑战性。在某些情况下，免疫组织化学染色和/或分子检测可以进行更明确的诊断或预测。回顾罕见子宫内膜肿瘤的经典形态学特征、这些肿瘤及其模拟肿瘤的病理特征，以及在子宫内膜肿瘤中使用免疫组织化学和分子检测的证据这些肿瘤的诊断。密歇根大学（安娜堡）病例和有关每个实体的相关文献的回顾。虽然这些不常见的子宫内膜肿瘤中的每一种都具有形态学模拟，但关键的组织学特征、免疫组织化学染色和分子测试可以进行准确的分类。© 2023美国病理学家学院。

A variety of uncommon malignant endometrial tumors can be challenging to diagnose because of overlapping morphology with more common entities. In some cases, immunohistochemical stains and/or molecular testing allow for more definitive diagnosis or prognostication.To review classic morphologic features of uncommon endometrial tumors, pathologic features of these tumors and their mimics, and the evidence for use of immunohistochemistry and molecular testing in the diagnosis of these tumors.University of Michigan (Ann Arbor) cases and review of pertinent literature about each entity.Although each of these uncommon endometrial tumors has morphologic mimics, key histologic features, immunohistochemical stains, and molecular testing allow for accurate classification.© 2023 College of American Pathologists.