Since the publication of the World Health Organization “blue book” in 2004, several recent
studies have provided new insights on the pathologic aspects of urachal neoplasms. The
proposed updates include modified criteria for the diagnosis of urachal carcinoma. A uniform
nomenclature for cystic tumors was lacking, and it is recommended that urachal mucinous
cystic tumors should be separated and classified in a manner similar to ovarian mucinous
neoplasms. The spectrum includes mucinous cystadenoma, mucinous cystic tumor of low …