Case report: persistence of lipiodol for 13 months in metastatic deposits in the liver on computed tomography.

The computed tomography (CT) findings in a 17-year-old male student with liver metastases from a primary adenocarcinoma of the rectum are presented. Lipiodol-enhanced CT 4 days after lipiodol infusion demonstrated several metastases not visible on conventional CT. A repeat CT 13 months later showed lipiodol to have been retained within the original lesions and also demonstrated new metastatic deposits free of lipiodol. Although persistence of lipiodol for up to a year has been reported by workers in Japan imaging hepatocellular carcinoma (Yumoto et al., 1985) this experience has not been confirmed in the UK (Raby et al., 1989). There are relatively few reports investigating metastatic adenocarcinoma (Nakakuma et al., 1985), none of which refers to persistence of lipiodol over 1 year. This case report demonstrates the ability of lipiodol-enhanced CT to detect occult metastases and also to facilitate their follow-up and differentiation from newer lesions.