Abstract
BACKGROUND: The urachus is the embryological remnant of the cloaca and allantois. Failure of its regression can cause diseases any time after birth. It is difficult to differentiate an abscess from urachal adenocarcinoma based on the clinical presentation and image findings. Cystitis glandularis reflects chronic irritation of the bladder urothelium, and tumor-like florid cystitis glandularis can be misdiagnosed as malignancy. We report a patient with concurrent urachal abscess and florid cystitis glandularis which increased the resemblance of malignancy. CASE PRESENTATION: A 57-year-old female was incidentally found to have a heterogeneous pelvic mass abutting the urinary bladder. A cystoscopy examination revealed protruding tumors located in the bladder dome. Her blood test results were all normal, and urinalysis showed microscopic hematuria. Urachal cancer was diagnosed and en bloc excision of the umbilicus, tumor, and the involved bladder dome was performed. Pathology revealed urachal abscess with concurrent cystitis glandularis within the urinary bladder. No malignancy was identified in the resected specimen. CONCLUSIONS: It is challenging to distinguish urachal abscess from a malignant tumor based on the clinical presentation and imaging studies. As in our case, the coexistence of urachal abscess and tumor-like florid cystitis glandularis increased the resemblance to a malignancy. This is the first reported case of the concurrence of these two disease entities, and emphasizes that the detection of bladder tumors on cystoscopy is not sufficient to make the diagnosis of urachal cancer with bladder involvement.