Preoperative Accuracy of Diagnostic Evaluation of the Urachal Mass

Abstract

Urachal carcinoma is a rare urological neoplasm that arises along the urachal remnant from umbilicus to bladder dome. To our knowledge no published study has examined the diagnostic accuracy of modern preoperative testing to differentiate urachal carcinoma from a benign urachal cyst and spare the resection of potentially benign urachal tissue. We determined whether a urachal mass could be safely diagnosed preoperatively. We reviewed the records of 104 patients with a urachal mass treated between 1979 and 2011. Study exclusion criteria were unresectable metastatic disease at presentation, no surgery and management by transurethral resection alone. Of the patients who remained only 65 had preoperative diagnostic testing as well as definitive pathological results available for analysis. Mean age was 51 years. Of the patients 86% were white and 65% were male. The accuracy of diagnosis based on preoperative tests was compared to that of final pathology (cancer or benign). A total of 57 tumors (87%) were malignant and 83% of the masses were adenocarcinoma. Compared to computerized tomography, cytology and exploration under anesthesia, transurethral resection of bladder tumor had the highest sensitivity (0.93), specificity (1) and positive predictive value (1) but low negative predictive value (0.5). Study limitations included small cohort size and few benign urachal masses for comparison. No test has a high enough negative predictive value to prevent urachal mass excision. With few treatment options for localized, advanced and metastatic urachal cancer, these data suggest that early excision remains the best treatment for a suspicious urachal mass.