"Look Before You Leap": Urachal Mass in Adults

Abstract

Diseases of the urachal remnant can present at any age. Urachal adenocarcinoma is the most frequent cause of urachal mass in adults, albeit infected urachal cyst constitutes a significant number. Lack of typical clinical and imaging findings combined with absence of definitive guidelines makes evaluation of urachal mass in adults very challenging. We present a case of a 58-year-old man presenting with an urachal mass with overlapping clinical and imaging findings mimicking urachal malignancy which later turned out to be an infected urachal cyst.

Keywords: Urachal adenocarcinoma; Urachal cyst; Urachus.

Figure 1

Ultrasound showed a moderate sized, ill-defined, heterogeneously hypoechoic mass (arrow) predominantly extending exophytically antero-superior to the dome of bladder with minimal indentation into the bladder wall. On color Doppler, no significant vascularity was noted.

Figure 2

(a) Axial CT image of lower abdomen in venous phase showed moderate sized oval hypo-enhancing mass (arrow) with thick and irregular peripheral enhancement and central non-enhancing low attenuation area with ill-defined margins arising from the dome of the urinary bladder with exophytic growth anteriorly. Moderate thickening of the dome of the urinary bladder was noted. Rest of the bladder wall was normal. Infiltration into the surrounding region with moderate perilesional fat stranding was noted. Fat planes with recti muscles were maintained. (b) Axial plain CT image of lower abdomen showed a small focus of calcification (arrow) in the periphery of the lesion. (c) Axial CT image of lower abdomen in venous phase at a higher section showed infiltration into the surrounding region with moderate perilesional fat stranding (arrow). (d) Sagittal CT image of abdomen in venous phase showed mass arising from dome of urinary bladder with maintained fat planes with abdominal wall (arrow) and displacement of the small bowel loops. (e) Coronal CT image of abdomen in venous phase showed mass arising from dome of urinary bladder (arrow) with superior displacement of the small bowel loops.

Figure 3

(a) Gross specimen of the resected mass in toto. Mass was surrounded by fibrofatty tissue. One aspect showed bladder mucosa along with bladder wall (red arrow). The other aspect of the mass shows umbilical skin (blue arrow). (b) Cut section of the gross specimen. Thick pus material was drained. The inner wall of cyst cavity showed irregular surface with slough (arrow).

Figure 4

Photomicrograph showed dense polymorphic inflammatory infiltrate (arrow) in the cyst wall and also in the central area of bladder mucosa. The cyst wall showed lining made up of vascular granulation tissue.