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URACHAL REMNANT MALIGNANCY

Case history A 20 year old female was admitted

with two months history of abdominal pain, constipation, weight loss and discharging sinus tract having past history of appendicectomy with pelvic abscess before 9 months.

Further ultrasonography and Contrast CT scan abdomen with per rectal positive contrast was performed.

Ultra-sonography with pulsed wave curvilinear transducer showing heterogeneously hypo echoic mass lesion ( arrow head) with internal air foci (thin arrow) and posteriorly infiltration into sigmoid colon ( thick arrow).

Ultra-sonography with linear probe showing same finding with linear sinus tract (star) formation in anterior abdominal wall.

Plain Axial CT scan showing heterogeneously hypo dense lesion in pelvic cavity. Linear tract of positive rectal contrast into it with few air foci.

Plain Axial CT scan showing superficial extension of lesion with sinus tract formation. 

Contrast Enhanced Axial CT scan showing heterogeneous enhancement with posteriorly sigmoid colon involvement. 

Contrast Enhanced Sagittal CT scan showing heterogeneous enhancement of supra-vesicle lesion with two sinus tract formation in anterior abdominal wall, inferiorly lesion involves superior wall of bladder with air foci in bladder and sigmoid colon extension posteriorly.

Malignant Urachal neoplasm are rare, representing less than 0.5% of all bladder cancers .

Although the normal urachus is most commonly lined by the transitional epithelium, Urachal carcinoma predominantly manifests as adenocarcinoma (90% of cases).

It is believed to arise from malignant transformation of columnar or glandular metaplastic epithelium and mucin production is found in up to 75% of cases on histological analysis.

These tumours can be silent because of their extra peritoneal location, and consequently usually presents at an advanced stage, and often shows local invasion or metastases to the pelvic lymph nodes, lung, brain, liver, or bone.

The diagnostic evaluation for urachal carcinoma should include a careful history and physical examination. Although carcinoma of the urachus can occur in any site along the urachal tract, the most common locations are the dome of the bladder and the umbilicus.

REFERENCES 1. Yu JS, Kim KW, Lee HJ, et al. Urachal remnant

diseases: spectrum of CT and US findings. Radiographics 2001;21:451–61

2. Ashley RA, Inman BA, Sebo TJ, et al. Urachal carcinoma: clinicopathologic features and long-term outcomes of an aggressive malignancy. Cancer 2006;107:712–20

3. Koster IM, Cleyndert P, Giard RW. Best cases from the AFIP: urachal carcinoma. Radiographics 2009;29:939–42

4. Wong-You-Cheong JJ, Woodward PJ, et al. Neoplasms of the urinary bladder: radiologic-pathologic correlation. Radiographics 2006;26:553–80

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