Intraductal neoplasm of the intrahepatic bile duct: clinicopathological study of 24 cases.

Abstract

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.

• Authors: Yoshiki Naito, Hironori Kusano, Osamu Nakashima, Eiji Sadashima, Satoshi Hattori, Tomoki Taira, Akihiko Kawahara, Yoshinobu Okabe, Kazuhide Shimamatsu, Jun Taguchi, Seiya Momosaki, Koji Irie, Rin Yamaguchi, Hiroshi Yokomizo, Michiko Nagamine, Seiji Fukuda, Shinichi Sugiyama, Naoyo Nishida, Koichi Higaki, Munehiro Yoshitomi, Masafumi Yasunaga, Koji Okuda, Hisafumi Kinoshita, Masamichi Nakayama, Makiko Yasumoto, Jun Akiba, Masayoshi Kage, Hirohisa Yano
• Journal: World journal of gastroenterology (World J Gastroenterol) Vol. 18 Issue 28 Pg. 3673-80 (Jul 28 2012) ISSN: 2219-2840 [Electronic] United States
• PMID: 22851859 (Publication Type: Journal Article)

Chemical References

• MUC5AC protein, human
• Mucin 5AC
• Mucin-1
• Mucin-2
• Mucin-6
• TP53 protein, human
• Tumor Suppressor Protein p53
• beta Catenin

Topics

• Aged
• Bile Duct Neoplasms (diagnosis, physiopathology)
• Bile Ducts, Intrahepatic (physiopathology)
• Female
• Gene Expression Regulation, Neoplastic
• Humans
• Immunohistochemistry (methods)
• Male
• Middle Aged
• Mucin 5AC (biosynthesis)
• Mucin-1 (biosynthesis)
• Mucin-2 (biosynthesis)
• Mucin-6 (biosynthesis)
• Neoplasm Invasiveness
• Tumor Suppressor Protein p53 (biosynthesis)
• beta Catenin (biosynthesis)