Non-endometrioid adenocarcinoma of the uterine corpus: a review of selected histological subtypes

Understanding the etiology, presentation, evaluation, and management of selected non-endometrioid endometrial adenocarcinomas of the uterine corpus is needed to define optimal treatment regimens. The pathology and treatment of selected non-endometrioid endometrial adenocarcinomas of the uterus are reviewed and summarized. The most common non-endometrioid histology is papillary serous (10%), followed by clear cell (2% to 4%), mucinous (0.6% to 5%), and squamous cell (0.1% to 0.5%). Some non-endometrioid endometrial carcinomas behave more aggressively than the endometrioid cancers such that even women with clinical stage I disease often have extrauterine metastasis at the time of surgical evaluation. Therefore, when technically and medically feasible, comprehensive surgical staging is helpful for women with non-endometrioid endometrial cancer histology. Comprehensive surgical staging includes hysterectomy, bilateral salpingo-oophorectomy, pelvic and para-aortic lymphadenectomy, and cytological evaluation of the abdominal cavity. While whole abdominal radiotherapy has a limited role in early-stage uterine papillary serous carcinoma (UPSC) and clear cell carcinoma (CC), there may be a role for postoperative chemotherapy and volume-directed radiotherapy in both early-stage UPSC and CC. In the setting of optimally debulked advanced-stage disease, a combination of radiation and chemotherapy may be indicated. In the setting of recurrent disease or in women with residual disease after surgery, a platinum-based regimen or enrollment in a clinical trial is recommended. UPSC and CC are managed similarly since sufficient data to separate treatment recommendations are lacking. Because both histologies are associated with a high rate of recurrence, adjuvant therapy is recommended even in women with early-stage disease. The remaining cell types should be treated similar to endometrioid or other low-grade histologies.