[Actinomycosis mimicking urachal cancer].

Tumours and other diseases of the urachus are rare. A 67-year-old male presented with a history of recurrent urinary tract infection and ciprofloxacin therapy. Cystoscopy suggested secondary involvement of the bullous upper bladder wall. The subsequent CT-based diagnosis was of a tumour infiltrating the lower median abdominal wall, the urinary bladder and bowels. Bowel obstruction developed and this led to partial resection of the involved organs along with a Hartmann’s procedure. Histology revealed no neoplastic conditions, but proved abdominal actinomycosis of probable urachal origin based on the location of the tumour-like lesion and umbilical discharge among the symptoms. Urachal remnants were not identified in the perivesical tissues involved by the microabscess forming inflammation. Amoxicillin therapy was initiated. After a temporary urine leakage from the bladder, the patient became symptomless and was emitted from hospital. After 13 days, he was readmitted because of abdominal wound disruption, which was treated with negative-pressure wound therapy before the abdomen could be closed. At the time of reporting, he is still on amoxicillin, and has become symptomless again. Actinomycosis should be considered in the differential diagnosis of mass lesions of the urachal region. Orv Hetil. 2022; 163(4): 157–160.