A Late Presenting Urachal Remnant Tumour: Rare Adenocarcinoma Originated from Developmental Defect

Abstract

Occupying only 0.01% of all adult cancer patients, the rare entity urachal adenocarcinoma constitutes 22-35% of adenocarcinomas originating from urinary bladder. Though with the gradual descend of the bladder in the course of development urachus should turn into median umbilical ligament, exceptional persistence of it can give rise to urachal cyst or urachal adenocarcinoma in adulthood. With only 43% of survival rate for 5 years and mean survival between 12 and 24 months urachal carcinoma is a devastating disease. Diagnosis of it is based on the MD Anderson Cancer Centre (MDACC) criteria. Computed Tomography (CT) Scan and/or Magnetic Resonance Imaging (MRI) Scan of abdomen and pelvis are the major imaging modalities to proceed towards diagnosis and staging. Not only histopathological examination but also immune-histochemical expression of both CK7 and CK20 suffice to clinch the diagnosis. Though surgical intervention forms the mainstay of treatment, several regimens of chemotherapy have also been tried to fight against unresectable, residual, extensive urachal carcinomas. This case took place in a 52 years old male patient who was presented with a gradually enhancing infra-umbilical swelling with slow growing urinary symptoms. By dint of Ultrasonography (USG) and Contrast Enhanced CT (CECT) scan of whole abdomen the tumour was detected involving the bladder wall and the anterior abdominal wall. Cystoscopy was followed by upfront cytoreductive surgery. Histopathological examination revealed the diagnosis of an adenocarcinoma which was further confirmed to be an urachal remnant carcinoma with the help of immunohistochemistry. Post-operative CT scan showed residual disease involving bladder wall and was treated with an adjuvant platin based chemotherapy regimen.