urachal carcinoma

Adenocarcinoma of the urinary bladder is rare and accounts for only ~1% of all bladder cancers (90% are transitional cell carcinomas).

Pathology

Metaplasia of urinary bladder induced by chronic irritation or infection can lead to adenocarcinoma. Pathological types of adenocarcinoma of the urinary bladder are:

• mucinous adenocarcinoma
• signet-ring type
• papillary adenocarcinoma
• not otherwise specified (NOS)

Bladder adenocarcinoma may be subclassified as primary (two-thirds are non-urachal and one-third are urachal ) or secondary (metastases).

Etiology

• persistent urachal remnant (most common)
• cystitis glandularis (itself secondary to bladder outlet obstruction, chronic infection and/or bladder calculi)
• schistosomiasis (bilharziasis), especially where endemic
• associated with bladder exstrophy

Radiographic features

CT

Non-urachal adenocarcinoma

• diffuse bladder wall thickening
• stranding of perivesical fat
• regional lymphadenopathy
• invasion of rectus muscles

Urachal adenocarcinoma

• characteristically in the midline at the dome of the bladder, or along the course of urachus (from the bladder to umbilicus)
  • a midline, infraumbilical soft tissue mass with peripheral calcification is characteristically urachal adenocarcinoma unless proven otherwise (calcification in 70% of cases)
• usually large tumors (5-6 cm) with prominent extravesical component
• mixed solid-cystic appearance in most cases

MRI

Solid components of the tumor are isointense, while cystic mucinous component appears hyperintense on T2W images. Localizing a urachal carcinoma may be easier on the sagittal images.

Treatment and prognosis

Due to their extravesical location, urachal carcinomas present very late and thus carry a poor prognosis. Radical cystectomy is considered the treatment of choice. However, en bloc resection of the extravesical component, adjacent peritoneum and the abdominal wall is also needed.

Siehe auch:

• Urachusrest
• Blasenekstrophie
• cystitis glandularis
• Urothelkarzinom
• Harnblasenkarzinom
• Neoplasien der Blase
• Plattenepithelkarzinom der Harnblase
• Sister Mary Joseph Knoten
• umbilikale Endometriose
• Tumoren im Nabel

und weiter:

• vesicourachal diverticulum
• Verdickung der Blasenwand
• mucinous adenocarcinoma of the urachus
• Endometriose am Urachus
• Transitionalzellkarzinom der Blase
• SCC of the bladder
• Adenokarzinom der Harnblase