Urachal Tumor: A Case Report of an Extremely Rare Carcinoma

Abstract

The urachus is a tubular structure that connects the bladder to the allantois in the embryonic development, involuting after the third trimester. The urachus carcinoma is an extremely rare tumor that accounts for <1% of all bladder cancers. We report a case of a 46-year-old woman, with no past medical history, complaining of hematuria with 6-month duration and a physical exam and an abdominal computed topographic scan revealing an exophytic mass of 6.8 cm longer axis that grew depending on the anterior bladder wall, invading the anterior abdominal wall. Cystoscopy detected mucosal erosion. The biopsy showed structures of adenocarcinoma of enteric type. The surgical specimen showed urachus adenocarcinoma of enteric type with stage IVA in the Sheldon system and stage III in the Mayo system. This case has a 3-year follow-up without disease recurrence.

Atypical Presentation of a Urachal Carcinoma as an Enterocutaneous Fistula

“…In adults, the urachal remnants can still be found, commonly at the bladder dome [ 2 , 4 , 7 , 8 ]. The first description of urachal adenocarcinoma was made in 1863 [ 3 , 5 , 9 ]. Since then, more case reports and series have been described in the literature.…”

“…The criteria for the diagnosis of urachal carcinoma were defined by Sheldon et al and Mostofi et al and revised by Gopalan et al These included a dome tumor or elsewhere in the midline of the bladder, absence of cystitis cystic and cystitis glandularis, a sharp demarcation between the tumor and normal surface epithelium, enteric-type histology, and absence of a primary neoplasm elsewhere [ 3 , 6 - 7 , 13 - 15 ]. These criteria were further adapted and published by the World Health Organization [ 9 ]. MD Anderson Cancer Centre simplified the diagnosis of urachal carcinoma to any enteric-type adenocarcinoma with sharp demarcation between the tumor and the epithelium in the bladder [ 16 ].…”

“…Different staging systems for urachal carcinoma have been proposed, such as the Sheldon, Mayo, and Ontario staging systems [ 2 - 3 , 7 - 8 , 11 , 16 ]. However, their significance still needs validation in a larger series [ 9 ]. The applicability of the TNM staging system is limited for urachal carcinoma [ 13 - 14 ].…”

“…This is the treatment of choice, required to appropriately control the tumor [ 17 , 18 ]. Partial cystectomy offers similar outcomes to complete cystectomy, providing a higher quality of life [ 9 - 11 , 16 ]. However, to achieve negative margins, a complete cystectomy might be performed [ 6 ].…”

“…Furthermore, some studies suggest that a failure to resect the umbilicus has been associated with a higher risk of relapse and a poorer survival rate [ 7 , 11 , 13 ]. Other prognostic factors in urachal carcinoma have been described, such as pathologic stage, positive surgical margins, positive lymph nodes, and involvement of the peritoneal surface at the time of surgery [ 1 , 6 , 8 - 9 , 13 ]. Lymph node dissection might be recommended, but there is still doubt regarding the benefit of lymphadenectomy [ 8 , 10 - 11 , 16 , 18 ].…”