A 90-year-old woman was seen at the hospital because of swelling and pain of the umbilical region. A black umbilical stone 3 cm in size was confirmed at the umbilical region. There were tenderness and redness around the navel. She had no memory of washing the navel until now and had undergone no surgery. Abdominal plain x-ray examination showed no abnormal findings, but an abdominal CT scan revealed a lamellar stone 3 cm in size in the navel. Our attempts to squeeze the stone from the umbilical foramen were in vain, so that, under local anesthesia to the periumbilical area, the stone was removed from the sufficiently opened foramen. The removed stone was 27×26×13 mm in dimension. Dirt with unpleasant odor was present in the umbilical pouch after the stone was removed and umbilical inflammation was associated.
So far only several cases of umbilical stone have been reported in the Japanese literature. And no huge umbilical stone as we have difficulty in removal like in this case has been reported. This case is thought to be of very rare.