Urachus

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.

Abstract: BackgroundUrachal carcinomas occur mostly in the bladder dome, comprising 22% to 35% of vesical adenocarcinomas, and are generally treated by partial cystectomy with en bloc resection of the median umbilical ligament and umbilicus. Detailed pathologic studies with clinical outcome correlation are fe

Abstract: Aims The incidence, anatomical localization and histological appearances of secondary neoplasms of the urinary bladder are described, with emphasis on the points of distinction from primary tumours. Methods and results A retrospective study of cases at the Royal Hospitals Trust yielded a total of 282 secondary bladder neoplasms, representing 2.3% of all malignant bladder tumours in surgical specimens. The commonest primary sites were the colon (21% of secondary neoplasms), prostate (19%), rectum (12%) and cervix (11%). Most tumours from these sites reached the bladder by direct spread. The most common sites of origin of tumours metastatic to the bladder were stomach (4.3% of all secondary bladder neoplasms), skin (3.9%), lung (2.8%), and breast (2.5%). Secondary tumour deposits were almost always solitary (96.7%), and 54% were located in the bladder neck or trigone. Histologically, 54% of secondary tumours were adenocarcinomas. Immunohistochemical staining patterns with prostate-specific acid phosphatase, prostate-specific antigen, carcinoembryonic antigen, chromogranin and neurone-specific enolase were similar in primary vesical and urachal adenocarcinomas and secondary adenocarcinomas from the gastrointestinal tract. Conclusions The incidence of secondary bladder tumours is comparable to that of nontransitional cell primary tumours. Few secondary tumours have distinctive histological features, hence knowledge of the history and clinical investigations are particularly important in their diagnosis.