Gastric-type mucinous adenocarcinoma of the uterine cervix with neoadjuvant therapy mimicking clear cell carcinoma.

Gastric-type mucinous adenocarcinoma, an uncommon subtype of cervical carcinoma, is characterized by a distinct morphology and immunophenotype. Herein, we report a case of a 71-year-old woman who received neoadjuvant radiotherapy and chemotherapy after cervical biopsy revealed moderately differentiated invasive endocervical adenocarcinoma. Subsequently, the outside patient underwent radical hysterectomy with bilateral salpingo-oophorectomy. The post-neoadjuvant therapy hysterectomy specimen showed tumor cells with clear cytoplasm, hyperchromatic nuclei with irregular contours, which mimicked clear cell carcinoma. However, immunohistochemical staining showed that these tumor cells were positive for carcinoembryonic antigen, cytokeratin 7 (diffuse), and cytokeratin 20 (patchy), After review of the pretreatment cervical biopsy specimen, the tumor was favored to represent a gastric-type mucinous adenocarcinoma of the cervix. Pathologists should be aware of this rare tumor and its post-neoadjuvant therapy morphologic changes, which can make diagnosis more challenging.