Intraductal neoplasm of the intrahepatic bile duct: Clinicopathological study of 24 cases

AIM: To investigate the clinicopathological features of intraductal neoplasm of the intrahepatic bile duct (INihB). METHODS: Clinicopathological features of 24 cases of INihB, which were previously diagnosed as biliary papillomatosis or intraductal growth of intrahepatic biliary neoplasm, were reviewed. Mucin immunohistochemistry was performed for mucin (MUC)1, MUC2, MUC5AC and MUC6. Ki-67, P53 and β-catenin immunoreactivity were also examined. We categorized each tumor as adenoma (low grade), borderline (intermediate grade), and malignant (carcinoma in situ , high grade including tumors with microinvasion). RESULTS: Among 24 cases of INihB, we identified 24 tumors. Twenty of 24 tumors (83%) were composed of a papillary structure; the same feature observed in intraductal papillary neoplasm of the bile duct (IPNB). In contrast, the remaining four tumors (17%) showed both tubular and papillary structures. In three of the four tumors (75%), macroscopic mucin secretion was limited but microscopic intracellular mucin was evident. Histologically, 16 tumors (67%) were malignant, three (12%) were borderline, and five (21%) were adenoma. Microinvasion was found in four cases (17%). Immunohistochemical analysis revealed that MUC1 was not expressed in the borderline/adenoma group but was expressed only in malignant lesions (P = 0.0095). Ki-67 labeling index (LI) was significantly higher in the malignant group than in the borderline/adenoma group (22.2 ± 15.5 vs 7.5 ± 6.3, P < 0.01). In the 16 malignant cases, expression of MUC5AC showed borderline significant association with high Ki-67 LI (P = 0.0622). Nuclear expression of β-catenin was observed in two (8%) of the 24 tumors, and these two tumors also showed MUC1 expression. P53 was negative in all tumors. CONCLUSION: Some cases of INihB have a tubular structure, and are subcategorized as IPNB with tubular structure. MUC1 expression in INihB correlates positively with degree of malignancy.

Surgically treated diaphragmatic perforation after radiofrequency ablation for hepatocellular carcinoma

We review 6 cases of diaphragmatic perforation, with and without herniation, treated in our institution. All patients with diaphragmatic perforation underwent radiofrequency ablation(RFA) treatments for hepatocellular carcinoma(HCC) performed at Kurume University Hospital and Tobata Kyoritsu Hospital. We investigated the clinical profiles of the 6 patients between January 2003 and December 2013. We further describe the clinical presentation, diagnosis, and treatment of diaphragmatic perforation. The change in the volume of liver and the change in the Child-Pugh score from just after the RFA to the onset of perforation was evaluated using a paired t-test. At the time of perforation, 4 patients had herniation of the viscera, while the other 2 patients had no herniation. The majority of ablated tumors were located adjacent to the diaphragm, in segments 4, 6, and 8. The average interval from RFA to the onset of perforation was 12.8 mo(range, 6-21 mo). The median Child-Pugh score at the onset of perforation(8.2) was significantly higher compared to the median Child-Pugh score just after RFA(6.5)(P = 0.031). All patients underwent laparotomy and direct suture of the diaphragm defect, with uneventful post-surgical recovery. Diaphragmatic perforation after RFA is not a matter that can be ignored. Clinicians should carefully address this complication by performing RFA for HCC adjacent to diaphragm.