Enterobius vermicularis (pinworm) infection of the liver mimicking malignancy: Presentation of a new case and review of current literature.

INTRODUCTION: Enterobius vermicularis or "pinworm" infection of the liver is an extremely rare condition with only five cases previously reported in literature. It is characterized by the presence of granulomas in the liver with a necrotic core, containing adult helminthes or their ova. Because of the relatively mild symptomatology associated with this disease, prior to the arrival of modern imaging methods hepatic enterobiasis was an incidental intra-operative finding during abdominal surgery for other conditions. In recent years however, with high-resolution abdominal imaging readily available and the improved safety of hepatic resection, a lower threshold for treating suspicious hepatic nodules aggressively with surgery is being adopted. PRESENTATION OF CASE: We present the second case in international literature, where E. vermicularis of the liver was mistaken for malignancy and led to hepatic resection and perform a literature review of the five previously documented cases of hepatic enterobiasis. DISCUSSION: Our report identifies certain trends in this condition's aetiology and clinical behaviour, but due to its rarity definitive answers cannot yet be established.
CONCLUSION: We do not advocate a change in the current approach of suspicious hepatic nodules, but we do feel that better understanding of the mechanisms involved with hepatic enterobiasis could, in the future, prevent unnecessary surgery.