Corded and hyalinized endometrioid carcinoma: a rare case and review of the literature

Abstract Background Corded and hyalinized endometrioid carcinoma(CHEC) is a rare morphological variation of endometrioid carcinoma(EC) in the endometrium. Reports of CHEC were very limited. We represent the clinical and pathological findings of this rare endometrioid carcinoma in a 26-year-old woman and reviews the literatures updated on CHEC. Case presentation: A 26-year-old woman presented with abnormal vaginal bleeding for 3 months and the initial cervical biopsy revealed a mullerian mixed tumor in another clinic. Abdominopelvic computed tomography revealed a mass in the uterine cavity and cervix, suggesting a malignant tumor. Histologically, the tumor showed a biphasic pattern characterized by an appearance of 2 components, the conventional endometrioid carcinoma component and sex cord-like component with hyalinization. In the areas of sex cord-like elements, the epithelioid and spindle cells were usually seen around the glands, and mostly arranged in cords or trabeculaes, sometimes embedded within a richly hyalinized collagenous or sometimes myxoid matrix. Tumor cells in the sex cord-like region show a different immunohistochemical expression pattern from conventional adenocarcinoma. Cytokeratin(CK) and vimentin are positive in both components, and vimentin shows more diffuse positivity while CK is more restricted and focally expressed in tumor cells in the sex cord-like region. Complete loss of expression of E-cadherin and epithelial membrane antigen(EMA) was seen in tumor cells in the sex cord-like region whereas it was well preserved in the area of conventional adenocarcinoma. Nuclear expression of β-catenin was noted in tumor cells in the sex cord-like region. P53 was focally positive in both components. Based on histological and immunochemical examinations, the patient was diagnosed with CHEC. Conclusions CHEC is not uncommonly mistaken for a wide variety of diseases. It’s of great significance to raise the awareness of CHEC to avoid over-treatment caused by over-diagnosis, especially in young patients and in curettage. We report one case of CHEC in a 26-year-old woman which was misdiagnosed as a mullerian mixed tumor in the initial curettage specimen. The clinicopathologic, light microscopic, immunohistochemical features of this tumor are described and the differential diagnosis is discussed.