Musculo-Invasive Urachal Transitional Cell Carcinoma (TCC): Is It Really Sinister and Different?

Urachal remnants are found in a third of adults, commonly at the dome. They can be found anywhere along the bladder midline, including the anterior and posterior walls. As a single entity, urachal carcinomas are rare, comprising 0.01% of all adult cancers and 0.35% of all bladder cancers. The commonest urachal carcinoma is adenocarcinoma, but 5% of urachal growths are urothelial. Whenever a case of urachal carcinoma is discussed, it is presumed to be an adenocarcinoma, but people forget the possibility of a transitional cell carcinoma (TCC) occurring in the urachus. Also, there is confusion about whether it is a primary urachal TCC or has spread from the adjacent bladder mucosa. It is surprising to note that to date, only 13 cases of primary urachal TCC have been described, and hence, not much is known about this rare tumor. As of today, the factors affecting the prognosis in this rare tumor are, namely, four: grade, stage, margin status, and musculo-invasive nature. A thorough search of the literature did not reveal a single case that encompasses all four prognostic factors. To the best of our knowledge, ours is the first case of high-grade musculo-invasive urachal TCC presenting with early-stage disease. This enabled us to dissect which of the four factors, namely grade, stage, margin status, and muscle invasion, influences the prognosis. We would like to discuss the clinical features of the distinction between primary and secondary urachal TCC. We would also like to specially emphasize and discuss whether there is any behavioral change when compared to the more commonly occurring adjacent bladder TCC.