A subgroup of intrahepatic cholangiocarcinoma with an infiltrating replacement growth pattern and a resemblance to reactive proliferating bile ductules: 'bile ductular carcinoma'.

AIMS: The histogenesis and biological behaviour of peripheral intrahepatic cholangiocarcinoma (peripheral CC) remain unclarified. The aim of this study was to examine the growth pattern of peripheral CC (24 cases) in comparison with hepatocellular carcinoma (HCC, 27 cases) and metastatic colorectal adenocarcinoma (MCA, 24 cases). METHODS AND RESULTS: Tumour/surrounding liver borders were classified as: (i) fibrous encapsulation, (ii) compressive growth, and (iii) infiltrating replacement. Nineteen of 24 peripheral CCs showed (iii), whereas 23 of 27 HCCs showed (i) and 17 of 24 MCAs showed (ii). In (iii), carcinoma cells infiltrated the surrounding liver without compression, and hepatic supporting vascular structures such as portal tracts were secondarily incorporated into the tumour. In (i) and (ii), the surrounding liver was compressed and no or few portal tracts were incorporated within the tumour. Fifteen of 24 peripheral CCs were composed of carcinoma cells resembling reactive bile ductules and these cells were positive for neural cell adhesion molecule (NCAM), a marker of proliferating bile ductules. The remaining nine peripheral CCs were composed of ordinary adenocarcinoma and negative for NCAM. CONCLUSIONS: A subgroup of peripheral CCs with an infiltrating replacement growth pattern resembles reactive bile ductules and expresses NCAM. 'Bile ductular carcinoma' may be a better term for this subgroup.

MRI findings of primary biliary cirrhosis: correlation with Scheuer histologic staging.

Magnetic resonance imaging (MRI) findings of primary biliary cirrhosis (PBC; currently regarded as a vanishing bile duct syndrome) are not established. In this report, we describe our preliminary analysis of the relation between MRI findings and histopathologic staging of PBC and review clinical, morphologic, and MRI findings of PBC especially focusing on the staging of PBC.

Intrapancreatic accessory spleen: evaluation by CT arteriography.

BACKGROUND: Intrapancreatic accessory spleens are frequently confused with primary pancreatic tumors, and differentiation from neoplastic lesions is important to avoid an unnecessary laparotomy. We present three cases of intrapancreatic accessory spleen evaluated by computed tomographic arteriography (CTA) and discuss the characteristic findings. METHODS: CTA was performed, followed by digital subtraction angiography, with an injection of contrast material through a 4-F catheter placed in the celiac artery. Single-level dynamic CTA was also performed in two patients with a 30-s continuous scan in one breath-hold. RESULTS: CTA clearly demonstrated early inhomogeneous enhancement of the lesion, similar to the splenic parenchyma. On single-level dynamic CTA, inhomogeneous enhancement of the lesion in the early phase was diminished in the late phase. Multiplanar reformatted images obtained in two cases showed the deep cleft between the lesion and the pancreas, which suggested that the lesion was originally extrapancreatic. CONCLUSIONS: These two findings on CTA, inhomogeneous enhancement of the lesion and the deep cleft between the lesion and the pancreas, may help to confirm the diagnosis of an intrapancreatic accessory spleen.