Urachal Remnant Diseases: Spectrum of CT and US Findings

Abstract

Computed tomography (CT) and ultrasonography (US) are ideally suited for demonstrating urachal remnant diseases. A patent urachus is demonstrated at longitudinal US and occasionally at CT as a tubular connection between the anterosuperior aspect of the bladder and the umbilicus. An umbilical-urachal sinus manifests at US as a thickened tubular structure along the midline below the umbilicus. A vesicourachal diverticulum is usually discovered incidentally at axial CT, appearing as a midline cystic lesion just above the anterosuperior aspect of the bladder. At US, it manifests as an extraluminally protruding, fluid-filled sac that does not communicate with the umbilicus. Urachal cysts manifest at both modalities as a noncommunicating, fluid-filled cavity in the midline lower abdominal wall located just beneath the umbilicus or above the bladder. Both infected urachal cysts and urachal carcinomas commonly display increased echogenicity at US and thick-walled cystic or mixed attenuation at CT, making it difficult to differentiate between them. Percutaneous needle biopsy or fluid aspiration is usually needed for diagnosis and therapeutic planning. Nevertheless, CT and US can help identify most disease entities originating from the urachal remnant in the anterior abdominal wall. Understanding the anatomy and the imaging features of urachal remnant diseases is essential for correct diagnosis and proper management.

Case Report - Patent Urachus

“…However, a vestigial small lumen lined by a transitional epithelium is seen commonly in the fully developed infant [3] . Occasionally, the urachus may merge with one or both of the obliterated umbilical arteries, and there may be a slight deviation to the right or left of the mid line [4] .…”

“…Cilento et al [9] reported 45 UR excisions with three postoperative wound infections. Urachal anomalies are twice as common in men as those in women [4] , and are rarely observed in adulthood. Modes of presentation differ from those seen in children.…”

Enterocutaneous Fistula Formation of Meckel's Diverticulum via the Urachal Cyst in an Adult Patient: A Case Report and Literature Review

“…Most UC's are generally infected and the responsible microorganism is usually Staphylococcus aureus (47). Furthermore, infected UC can be radiologically mistaken for MD (48). But formation of enterocutaneous fistula from umbilicus after the penetration and perforation of MD into UC have not been reported yet.…”

A case of vesicourachal diverticulum containing calculus: MDCT urography findings

“…Understanding the anatomy and embryology of urachal cysts and remnants is critical in making the correct diagnosis and choosing an effective management strategy, which can avoid the complications of intraperitoneal rupture, or subsequent malignancy (1)(2)(3)(4).…”

“…However, persistence of an embryonic urachal remnant can give rise to various clinical problems, not only in infants and children but also in adults. Because urachal remnant anomalies are uncommon and manifest with nonspecific symptoms, definitive presurgical diagnosis is not easily made (1)(2)(3)(4)(5).…”