Sarcomatous Transformation in Undifferentiated/Dedifferentiated Endometrial Carcinoma: An Underrecognized Phenomenon and Diagnostic Pitfall

Vroobel, Katherine M.，Attygalle, Ayoma D.

International Journal of Gynecological Pathology: September 2020 - Volume 39 - Issue 5 - p 485-492

ABSTRACT

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 sarcomatousdifferentiation, 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.

原文獻DOI:

doi: 10.1097/PGP.0000000000000635

未分化/去分化子宮內膜癌的肉瘤轉化：尚未識別的組織學和診斷陷阱

摘要

未分化/去分化癌是一種侵襲性子宮內膜癌，至今仍未被廣泛認識，約占所有子宮內膜惡性腫瘤的9％。我們描述了3例未分化成分與肉瘤分化相關的病例，其特征為梭形細胞2例和異源性惡性軟骨1例。3例中有2例通過免疫組織化學證實錯配修復（MMR）缺陷。這種現象以前沒有被正式報道過并有誤診的可能性，尤其是在活檢樣本中。鑒別診斷可能包括子宮內膜間質肉瘤和呈梭形形態的3級子宮內膜樣腺癌。我們回顧了當前的文獻并提供了解決鑒別診斷的策略，建議的一組抗體包括EMA，E-鈣黏著蛋白和錯配修復蛋白，因為大約50％的病例顯示錯配修復表達的喪失。

I 譯者點評(Comments)

未分化/去分化子宮內膜癌是子宮內膜癌的一個特殊類型，其預后較2或3級子宮內膜樣癌差。如本文所述，其肉瘤轉化提示惡性混合苗勒氏瘤的另一種發病機理。有必要做進一步的病例研究以確認作者的結論。

II 文獻譯者