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an 86-year - old female was diagnosed with superficial , low - grade , non - muscle - invasive urothelial carcinoma of the bladder in 1996 .
she had past medical histories of multiple sclerosis , thoracic aortic aneurysm , and supraventricular tachycardia .
after an initial transurethral resection ( tur ) , she remained asymptomatic and had no tumor recurrence until october 2009 .
a single urothelial carcinoma situated near the left ureteric orifice was noted during a routine flexible cystoscopy .
an incidental 2.5-cm mucus - secreting diverticulum at the dome of the bladder was also noted during the same procedure .
a cold cup biopsy of the diverticulum wall was planned to occur simultaneously with a tur of the bladder tumor .
the tur of the bladder tumor was performed and the histology confirmed a low - grade , non - muscle - invasive urothelial carcinoma .
the bladder diverticulum was again visualized at the dome of the bladder during the procedure .
cold cup biopsies of the wall of the diverticulum revealed evidence of tubulovillous adenoma , possibly of urachal origin . clinically , the patient had no palpable suprapubic mass and a triple - phase computed tomography ( ct ) scan of the abdomen was normal . since then , the patient had regular surveillance cystoscopy in accordance with the guidelines on tat1 ( non - muscle - invasive ) bladder cancer by the european association of urology . in 2011 ,
an endoscopic resection of the urachal adenoma was performed and macroscopic clearance of the tumor was achieved .
the histology of the specimen revealed a moderately differentiated adenocarcinoma , enteric subtype , with evidence of lamina propria infiltration ( figs . 1 , 2 ) .
after careful consideration , taking into account the patient 's age , co - morbidities , and the lack of radiological evidence of extravesical disease , a partial cystectomy and urachalectomy was planned .
the intravesical approach was used initially to identify the macroscopic extent of the tumor with a 1-cm margin marked out with a barnes knife and with the bladder full .
laparotomy was then performed with excision of the urachus from the base of the umbilicus down to and including the lesion in the bladder as previously outlined .
benign lesions are most commonly adenomas . of the malignant lesions , over 80% are adenocarcinoma with enteric , mucinous , and signet ring subtypes , and the rest consist of sarcoma , urothelial carcinoma , and squamous cell carcinoma .
a ct scan of the abdomen may display tumor calcification and umbilical extension with extravesical disease .
the location of the tumor at the bladder dome , the sharp demarcation between the tumor and the normal urothelium , the presence of urachal remnants , and the absence of cystitis glandularis and cystitis cystic are diagnostic criteria for urachal neoplasm .
the recent reclassification of urachal tumors by the mayo clinic has simplified the previously known sheldon system   the mayo staging system divides urachal tumors into four stages : stage i , tumor confined to urachus and bladder ; stage ii , tumor extending beyond urachus and bladder ; stage iii , tumor infiltration of regional nodes ; and stage iv , tumor infiltration of non - regional nodes and distant sites .
most of the tertiary institutions adopt a multi - modal approach when treating patients with a urachal tumor . a local en bloc excision of the tumor mass with urachalectomy and umbilectomy results in possible long - term survival .
the median survival after platinum - based chemotherapy is limited for patients with extra - vesical disease .
intestinal metaplasia is the most common mechanism causing the transformation of a urachal adenoma into adenocarcinoma .
only 30 cases of villous adenoma have been found outside the large bowel , and only 4 cases of adenocarcinoma arising within a villous adenoma have been reported [ 5 - 7 ] .
the hypothesis was that a urachal tubulovillous adenoma shares similar oncogenes and tumor suppressor protein such as p53 with colonic tubulovillous adenoma .
the progression from colonic adenoma to adenocarcinoma is genetically well characterized and thus may be applicable in urachal tumors .
urachal adenoma and adenocarcinoma may in fact co - exist in a solitary lesion , representing a different spectrum of tumorigenesis
. a cold cup biopsy of a sizable urachal lesion can hence be falsely reassuring .
it is recommended that a urachal adenoma be regarded as a premalignant condition and be subject to endoscopic surveillance .
synchronous low - grade , non - muscle - invasive urothelial carcinoma and urachal adenoma is rare and there is no known genetic link between the two malignancies . the optimal management of synchronous urothelial carcinoma and urachal adenoma is not known .
the potential for malignant transformation of the urachal adenoma into adenocarcinoma proposes a unique clinical challenge .
regular endoscopic surveillance of the urachal adenoma should be mandated ; however , a protocol is difficult to formulate given the rarity of the urachal lesion .
one needs to weigh the rarity of the disease against its malignant potential when making a clinical decision .
a partial cystectomy with en bloc resection of urachal adenocarcinoma seems to be the widely accepted surgical approach for localized urachal adenocarcinoma .
a study by memorial sloan kettering cancer center showed a survival rate of 93% at 5 years with partial cystectomy .
a study by the mayo clinic showed a median survival of 10.8 years for stage i / ii disease and only 1.3 years for stage iv disease .
this compares similarly with the 5-year survival data for t1 high - grade urothelial carcinoma after radical cystectomy and favorably with the 5-year survival data for muscle - invasive urothelial carcinoma .
we recommend the use of the european association of urology urothelial carcinoma endoscopic surveillance protocol for a solidary urachal adenoma and also in the setting of a synchronous low - grade , superficial urothelial carcinoma with a urachal adenoma . in conclusion ,
clinicians need to be aware of the premalignant potential of urachal adenoma , and an endoscopic surveillance program should be instigated .
the late adenoma to adenocarcinoma transformation should be managed with partial cystectomy and en bloc resection of the urachus and umbilicus in well - selected patients .
malignant transformation of urachal adenoma is exceedingly rare , with intestinal metaplasia as the most common contributing mechanism . 
 it is recommended that a urachal adenoma be regarded as a pre - malignant condition and be subject to endoscopic surveillance . a local en block excision of the tumor mass with urachalectomy and umbilectomy results in possible long - term survival . 
 the median survival after platinum - based chemotherapy is limited for patients with extravesical disease . here 
 we report a case of synchronous urothelial carcinoma of the bladder and urachal adenoma that transformed into adenocarcinoma .