Urachal cancer

What is the urachus?

The urachus is a tube-like structure that forms in a developing embryo. It connects the umbilical cord to the urinary bladder before birth. After birth, the urachus usually shrinks into a small ligament. However, traces of the urachus (called urachal residues) can be detected in up to one-third of adults. Urachal residues usually do not cause any symptoms.

What is urachal cancer?

A growth of cancerous cells that starts in the urachus is called urachal cancer.

Because of its location, urachal cancer can grow into the abdominal wall and the abdominal cavity. Often it infiltrates the roof of the urinary bladder. Urachal cancer can grow for a long time before causing symptoms. As a result, it is often detected at later stages.

Fig. 1: Anatomical illustration of an intact (patent) urachus. This situation is very rare in an adult. If urachal residues remain, they are usually partial or microscopic.
Fig. 1: Anatomical illustration of an intact (patent) urachus. This situation is very rare in an adult. If urachal residues remain, they are usually partial or microscopic.
Fig. 2: partially patent opening externally, blind internally.
Fig. 2: partially patent opening externally, blind internally.
Fig. 3: partially patent urachas opening internally blind externally.
Fig. 3: partially patent urachas opening internally blind externally.
Fig. 4: Cyst of urachas.
Fig. 4: Cyst of urachas.

Outcome

About 20% of urachal cancer patients cannot be cured by the time they develop symptoms. After treatment, about one-third will have relapse or their disease will spread. Average survival is 50% at 5 years.

This information was produced by the European Association of Urology (EAU) Patient Information Working Group and is based on a narrative review of the literature.

  • Dr. Mark Behrendt, Amsterdam (NL)
  • Dr. Henning Reis, Essen (DE)