Ultrasound diagnosis of carcinoma of the urachus.

In a 48-year-old man with dysuria and microscopic haematuria, pyelography, cystoscopy and bimanual bladder palpation showed no definite abnormality. Because of continued symptoms, ultrasound scanning of the abdomen was done three months later. The examination revealed a tumour in close relation to the top of the bladder. Malignant cells were aspirated at ultrasonically guided puncture, and a urachus tumour was suspected. For early diagnosis of urachus tumours, ultrasound investigation of vague bladder symptoms is required.