A 42-year-old man who had no local or systemic symptoms presented with a yellowish tumor in the foreskin of his penis. He had travelled to Hokkaido to harvest insects, and recognized this tumor after returning home. Since it did not disappear after several days, he visited our hospital. The tumor was suspected to be due to an arthropod. En bloc resection including the arthropod was performed. Pathological findings demonstrated that the arthropod was Ixodes persulcatus. There were no symptoms after the surgery during the follow up. Ixodes persulcatus is a source of
Lyme disease. Approximately ten patients develop
Lyme disease per year, half of which are from Hokkaido in Japan. The case reported here was of a very rare tick-bite
disease in the penis.