Department of Cellular Pathology, The Royal Marsden Hospital, London, UK.
Int J Gynecol Pathol. 2020 Sep;39(5):485-492. doi: 10.1097/PGP.0000000000000635.
Undifferentiated/dedifferentiated carcinoma is an aggressive endometrial carcinoma which remains underrecognized but may account for up to 9% of all endometrial malignancies. We describe 3 cases in which the undifferentiated component was associated with sarcomatous differentiation, characterized by spindled cells in 2 cases and heterologous malignant cartilage in 1 case. Two of the 3 cases demonstrated mismatch repair deficiency by immunohistochemistry. This phenomenon has not previously been formally reported and increases the likelihood of misdiagnosis, especially within biopsy samples; differential diagnoses may include endometrial stromal sarcoma and grade 3 endometrioid adenocarcinoma with spindled morphology. We review the current literature and provide strategies for resolving the differential diagnoses, with a suggested panel of antibodies which includes EMA, E-cadherin, and mismatch repair proteins as approximately 50% of cases show loss of mismatch repair expression.
未分化/去分化癌是一种侵袭性子宫内膜癌，目前仍未被充分认识，但可能占所有子宫内膜恶性肿瘤的 9%。我们描述了 3 例未分化成分伴肉瘤样分化的病例，其中 2 例为梭形细胞，1 例为异源性恶性软骨。这 3 例中的 2 例通过免疫组织化学显示错配修复缺陷。这种现象以前没有正式报道过，增加了误诊的可能性，尤其是在活检样本中；鉴别诊断可能包括子宫内膜间质肉瘤和 3 级子宫内膜样腺癌伴梭形形态。我们回顾了目前的文献，并提供了解决鉴别诊断的策略，建议使用一组抗体，包括 EMA、E-钙黏蛋白和错配修复蛋白，因为大约 50%的病例显示错配修复表达缺失。
