Carcinoma simultaneously involving the endometrium and ovary is encountered frequently enough in clinical practice that guidelines are needed for consistent surgical pathology reporting and patient management. This review will cover the history and terminology of this phenomenon, summarize current practices, and provide a practical reporting framework for daily use. By focusing on conventional surgical pathology parameters, including molecular subtype, while avoiding clonality considerations, it is possible to consistently provide the necessary information to guide treatment. There remain some outstanding issues that require further research, which will be identified and discussed.