Pictures in Clinical Medicine

A 33-year-old Japanese man was referred to our hospital with a history of spontaneous discharge of tapeworm segments. He also had a history of a similar episode three month previously. He was asymptomatic. He denied having recently eaten raw fish such as trout, and did not have frequent travelling habits. Laboratory data, including complete blood count, eosinophil and vitamin B12 levels were within normal limits. A scolex at the small intestine was identified 2 hours and 52 minutes into the capsule endoscopy examination (Picture 1). Mature Proglottids were observed in the region of the small intestine at 3 hours and 47 minutes (Picture 2). A Diphyllobothrium latum/nihonkainese egg was identified by microscopic stool examination. Diphyllobothrium latum/nihonkainese infection was established on the basis of these findings, and he was treated with a single dose of praziquantel (600 mg) followed by ingestion of a cathartic (magnesium citrate). A worm with a scolex and mature proglottids about 8 m in length was expelled after 5 hours. Diphyllobothrium latum/nihonkainese is one of the parasites acquired from fish in Japan (1). This is an unusual case of Diphyllobothrium latum/nihonkainese infection in which the suspected source of infection is uncertain, it was identified by capsule endoscopy, and was successfully treated with praziquantel.