Imaging evaluation of Urachus: Pictorial essay.

The urachus is a vestigial tubular structure extending from the bladder's anterior surface to the umbilicus, formed during embryonic development. Normally, it obliterates to form the median umbilical ligament; however, in some cases, remnants persist, leading to urachal anomalies such as fistulas, cysts, and diverticula. Urachal anomalies can result in complications, including infections and neoplasms, with malignant urachal adenocarcinoma being rare but more common than benign neoplasms. This cancer typically affects men aged 40-70, with symptoms like hematuria, abdominal pain, and palpable masses. Due to its extraperitoneal location, urachal carcinoma is often asymptomatic until advanced stages. Diagnosis of urachal carcinoma involves cystoscopy, imaging modalities like CT and MRI, and serum markers. Imaging plays a key role in detecting midline masses, often containing both solid and cystic components. CT and MRI can evaluate tumor extent and local invasion, but further assessment, such as biopsy, is often required. Surgical resection remains the primary treatment, with partial or radical cystectomy providing comparable outcomes. Despite advances in chemotherapy and immunotherapy, prognosis remains poor, with a 5-year survival rate of around 50%, particularly in cases with lymph node involvement or metastasis. [ABSTRACT FROM AUTHOR]