A case of painful umbilical hernia

Abstract

The umbilicus is the remnant of feto-maternal connection. It is also the site of presentation of pathologies related to embryological remnants such as the allantois and vitello-intestinal duct. We describe a case of an infected urachal cyst manifesting as a painful umbilical hernia in an adult. Such a case has not been reported before. A 41-year-old woman presented with acute onset of periumbilical pain. She had no gastrointestinal or urinary symptoms. She had had a small umbilical lump for more than 20 years with no history of discharge or infection. She had also had her umbilicus pierced at a hairdressers under aseptic conditions a week before this admission, but the ring was removed after two days as it was very painful. Examination revealed a small irreducible umbilical lump which was extremely tender. She also had tenderness in the infra-umbilical region. A clinical diagnosis of umbilical hernia containing infarcted omentum or a Richter's hernia was made. Urgent exploration revealed the presence of a long, inflamed, urachal cyst extending from the umbilicus to the dome of the urinary bladder. The cyst was excised and the dome of the bladder repaired. The bladder was drained by catheter for 48 hours. Histology later confirmed the structure to be an infected urachal remnant. Embryologically, the urachus develops from the allantois and ventral part of the cloaca. Before birth, the connection between the urinary bladder and the umbilicus is sealed off and remains as a fibrous tract called the median umbilical ligament. Incomplete closure can result in a patent urachus, urachal sinus, urachal cyst or urachal diverticulum. Urachal anomalies are clinical rarities. The incidence of congenital urachal abnormalities detected at birth has been reported to be less than 2 per 300,000 admissions to a paediatric hospital.1 Urachal disease presenting in adults is extremely rare, less than 200 cases having been reported in the English literature. Although they are uncommon in humans, urachal anomalies are fairly common in mammals such as the horses, cows and cats.2 Histologically the cyst contains an inner lining consisting of transitional epithelium surrounded by a layer of connective tissue, and an outer muscular layer continuous with the detrusor muscle. Most urachal cysts present with sepsis. Asymptomatic lesions are found incidentally during laparotomy or radiological imaging. In our patient we feel that the infection was introduced into the asymptomatic cyst by umbilical piercing, even though it was done under aseptic conditions. Surgical exploration is usually necessary to confirm the diagnosis and the need for excisional therapy. Recently, ultrasound examination has helped significantly in preoperative diagnosis,3 hence the early introduction of antimicrobial therapy. Surgical treatment consists of radical excision of the tract to avoid recurrence of symptoms and the potential risk of developing urachal carcinoma in the residual tissue.4 Injection of methylene blue into the tract intraoperatively has also been advocated in difficult circumstances to identify all the tissue to be excised.5