Pinworm granuloma of the liver.

A granuloma containing Enterobius vermicularis was found in the liver of a 62-year old woman from Arkansas who had a 4-year history of recurrent surgery for adenocarcinoma of the colon. Hematogenous spread and direct penetration of the liver preceded by either invasion of the peritoneum through unhealthy or traumatized intestinal tissue, or from migration up the genital tract are the infective mechanisms considered. This type of parasitic liver lesion is the third reported case, the first in North America, and the first in a female.