Urachal Cancer

Urachal cancer is a rare form of cancer that can sometimes involve the bladder, but does not arise from the urothelium and is therefore not bladder cancer in the usual sense. The disease arises from malignant transformation of rests of enteric epithelium in the urachus an embryonic structure located between dome of the bladder and the umbilicus. Urachal cancer can occur at any site along the urachal tract. The most common locations are the umbilicus and the dome of the bladder. Urachal cancer was first described in 1863 by Hue and Jaequin.

Urachal cancer can exist for some years without any symptoms. Sometimes the first symptom is haematuria (blood in the urine), but of course this can have many other causes. Urachal cancer does not seem to respond to the usual chemotherapy treatments for bladder cancer, but recently there seems to have been more success using chemotherapy regimens used for bowel cancer. Surgery is the mainstay of treatment for clinically localized disease, and has been shown to be more successful when the entire urachal remnant and bladder dome are taken "en bloc."

The diagnosis of Urachal cancer can be difficult, and unfortunately there are no specific symptoms. The CT appearance is quite characteristic. Not only does it often progress silently, but because the most common presentation involves blood in the urine, it is commonly confused with conventional bladder cancer initially.

The prognosis for patients with metastatic or recurrent disease is poor, with median survivals reported in the range of 1 to 2 years. There are anecdotal reports of long-term survival with bowel cancer regimens, but these are clearly exceptional.