Hepatic pinworm infestation misdiagnosed as a liver metastasis in a patient with colonic adenocarcinoma

An extra-intestinal infestation of Enterobius vermicularis (pinworm) is uncommon. We present a case of hepatic infestation of pinworm in a 57-year-old woman, misdiagnosed as a colorectal adenocarcinoma metastasis. The route of migration from the intestine to the liver is not well established but the most plausible route seems to be hematogenous. In concordance with previously published cases, the hepatic pinworm infestation is usually localised superficially in the right liver lobe. Hence solitary lesions in this location detected radiologically should be interpreted carefully. Additionally, the serum CEA level could be useful to distinguish pinworm from malignancy.