[Two cases of urachal cyst].

Case 1: A lower abdominal large painful mass was recognized by palpation, CT scan and ultrasonography in a 64-year-old house wife. Urine cytology was negative. The mass at the dome of bladder was covered with normal epithelium cystoscopically. Aspiration cytology of the lower abdominal mass demonstrated no malignancy and total excision of urachal remnant with a portion of bladder wall was carried out. Histologically, the mass was an urachal cyst with granulomatous change infected with C group beta-streptococcus. Case 2: A 46 year-old male engineer complained of asymptomatic hematuria. Cystoscopic examination revealed a small bleeding lesion at the dome of bladder. Urine cytology was negative. CT scan and ultrasonography revealed a tiny cystic mass lesion with irregular density. Biopsy or aspiration cytology appeared difficult because of the size and localization of the mass. En bloc segmental resection of urachal remnant was carried out. Since intraoperative rapid histological examination of the specimen confirmed no malignancies, dissection of pelvic lymph node was not performed. Urachal cysts presented above were suspicious of malignant degeneration from findings of imaging examination. Either preoperative or intraoperative histological examination in such cases appears to be indispensable to avoid unnecessary extensive operation as well as to perform radical operation required for malignant lesions.