Corded and hyalinized endometrioid carcinoma: A case report

Corded and hyalinized endometrioid carcinoma (CHEC) is a rare histologic variant of endometrioid adenocarcinoma first described in 2005. Due to its biphasic appearance, comprising traditional low-grade endometrioid carcinoma and corded/spindled cells within a hyalinized stroma, CHEC may be misdiagnosed as more aggressive malignancies, including uterine carcinosarcoma. Here is presented the case of an 84-year-old woman who was initially diagnosed with uterine carcinosarcoma but was ultimately found to have FIGO Grade 2 Stage IA2 endometrioid adenocarcinoma with CHEC features following multi-institutional pathologic review. Histopathologic and molecular characterization, including wild-type p53 staining, nuclear β-catenin expression, and a CTNNB1 exon 3 mutation, facilitated the amended diagnosis. Given the updated diagnosis, adjuvant treatment was de-escalated to vaginal brachytherapy alone, sparing the patient unnecessary systemic chemotherapy. This case underscores the critical role of molecular and immunohistochemical analysis in differentiating CHEC from more aggressive endometrial cancers, thus preventing overtreatment. Increased awareness and documentation of CHEC are essential to refining diagnostic criteria, informing prognosis, and optimizing patient management. Future studies are needed to further characterize the molecular landscape and clinical behavior of this rare entity.