Preoperative assessment of multicentric occurrence in synchronous small and multiple hepatocellular carcinoma based on image-patterns and histological grading of non-cancerous region.

Recent studies have shown that the prognosis of patients with multicentric occurrence (MO) of hepatocellullar carcinoma (HCC) after curative resection, whether synchronous or metachronous, is significantly better than that of patients with intrahepatic metastasis (IM). We attempted to elucidate a group with high probability of MO of HCC by comparing the preoperative ultrasonography (US), computed tomography during arterial portography (CTAP) and CT arteriography (CTA) images with the histological grading of the non-cancerous region of the liver. The imaging and pathological characteristics of 97 nodules in 45 patients diagnosed as having small (<5cm) and oligonodular HCCs preoperatively were investigated. Histological diagnoses were as follows: 18 MO, 23 IM, and 4 unclassified (HCC with benign nodule). Histological grade of the liver tissue was assessed using the hepatitis activity index (HAI) score. No significant differences in tumor location and the mean size of co- or daughter nodules were noticed between the MO and IM patients. Of the 38 nodules in the MO patients, 20 were diagnosed as hyperechoic lesions on US, 20 as negative enhanced lesions on CTA and 12 as having positive portal flow on CTAP. A comparison of image-patterns between the synchronous nodules revealed that the MO group showed different images in at least one imaging technique, whereas in most IM patients similar images were produced by two or three imaging techniques. Moreover, all MO patients had an [Formula: see text], although more than half the IM patients had an [Formula: see text]. In patients with small and oligonodular HCCs, the nodules are highly likely to display MO, when showing both 1 or more different image patterns among US, CTA and CTAP and severe hepatitis such as HAI score >/=8.