Kazuhiko Ueda

Vascular supply in adenomatous hyperplasia of the liver and hepatocellular carcinoma: A morphometric study

Vascular supply of adenomatous hyperplasia (AH) of the liver, a preneoplastic or early neoplastic lesion of hepatocellular carcinoma (HCC), and that of HCC were morphometrically examined. Seventy-three nodules of AH were divided into 43 ordinary and 30 atypical AHs. The latter showed a variety of hepatocellular atypias that were, however, insufficient to make a diagnosis of HCC, while the former lacked such atypias. Arteries were slightly more numerous and portal veins were slightly less frequent in both ordinary and atypical AHs compared with the surrounding liver. In ordinary AHs, cumulative areas of arterial lumen and portovenous lumen were almost equal to or less than those in the surrounding liver in two thirds of our cases. The cumulative area of arterial lumen was equal to, and that of portovenous lumen was less than, the cumulative area in the surrounding liver in the remaining one third of our cases. In a majority of atypical AHs, the cumulative area of arterial lumen was equal to, and that of portovenous lumen was less than, the cumulative area in the surrounding liver. In most HCC nodules, the number and cumulative luminal area of arteries were much more, and those of portal veins were much less, than the number and cumulative area in the surrounding liver. The relative number and cumulative luminal area of abnormal arteries compared with all arteries showed a stepwise increase in the following order: ordinary AH (20.7% and 17.5%), atypical AH (46.8% and 52.5%), and HCC (93.6% and 92.0%). These data suggest that ordinary AH, atypical AH, and HCC are different in vascular supply, and that these differences may reflect sequential changes in the hemodynamic state during hepatocarcinogenesis.

Characteristic findings in images of extra-pancreatic lesions associated with autoimmune pancreatitis.

PURPOSEnAutoimmune pancreatitis is a unique form of chronic pancreatitis characterized by a variety of extra-pancreatic involvements which are frequently misdiagnosed as lesions of corresponding organs. The purpose of this study was to clarify the diagnostic imaging features of extra-pancreatic lesions associated with autoimmune pancreatitis.nnnMATERIALS AND METHODSnWe retrospectively analyzed diagnostic images of 90 patients with autoimmune pancreatitis who underwent computer-assisted tomography, magnetic resonance imaging, and/or gallium-67 scintigraphy before steroid therapy was initiated.nnnRESULTSnAIP was frequently (92.2%) accompanied by a variety of extra-pancreatic lesions, including swelling of lachrymal and salivary gland lesions (47.5%), lung hilar lymphadenopathy (78.3%), a variety of lung lesions (51.2%), wall thickening of bile ducts (77.8%), peri-pancreatic or para-aortic lymphadenopathy (56.0%), retroperitoneal fibrosis (19.8%), a variety of renal lesions (14.4%), and mass lesions of the ligamentum teres (2.2%). Characteristic findings in CT and MRI included lymphadenopathies of the hilar, peri-pancreatic, and para-aortic regions; wall thickening of the bile duct; and soft tissue masses in the kidney, ureters, aorta, paravertebral region, ligamentum teres, and orbit.nnnCONCLUSIONSnRecognition of the diagnostic features in the images of various involved organs will assist in the diagnosis of autoimmune pancreatitis and in differential diagnoses between autoimmune pancreatitis-associated extra-pancreatic lesions and lesions due to other pathologies.

Quantitative Evaluation of Liver Function with Use of Gadoxetate Disodium–enhanced MR Imaging

PURPOSEnTo determine whether liver function correlating with indocyanine green (ICG) clearance could be estimated quantitatively from gadoxetate disodium-enhanced magnetic resonance (MR) images.nnnMATERIALS AND METHODSnThis retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Twenty-three consecutive patients who underwent an ICG clearance test and gadoxetate disodium-enhanced MR imaging with the same parameters as were used for a preoperative examination were chosen. The hepatocellular uptake index (HUI) from liver volume (V(L))and mean signal intensity of the liver on contrast-enhanced T1-weighted images with fat suppression (L(20)) and mean signal intensity of the spleen on contrast-enhanced T1-weighted images with fat suppression (S(20)) on 3D gradient-echo T1-weighted images with fat suppression obtained at 20 minutes after gadoxetate disodium (0.025 mmol per kilogram of body weight) administration was determined with the following equation: V(L)[(L(20)/S(20)) - 1]. The correlation of the plasma disappearance rate of ICG (ICG-PDR) and various factors derived from MR imaging, including HUI, iron and fat deposition in the liver and spleen, and spleen volume (V(S)), were evaluated with stepwise multiple regression analysis. The difference between the ratio of the remnant HUI to the HUI of the total liver (rHUI/HUI) and ratio of the liver remnant V(L) to the total V(L) (rV(L)/V(L)) was evaluated in four patients who had segmental heterogeneity of liver function.nnnRESULTSnHUI and V(S) were the factors significantly correlated with ICG-PDR (R = 0.87). The mean value and its 95% confidence interval were 0.18 and 0.01 to 0.34, respectively, for the following calculation: (rHUI/HUI) - (rV(L)/V(L)).nnnCONCLUSIONnThe liver function correlating with ICG-PDR can be estimated quantitatively from the signal intensities and the volumes of the liver and spleen on gadoxetate disodium-enhanced MR images, which may improve the estimation of segmental liver function.

'Atypical adenomatous hyperplasia' in liver cirrhosis : low-grade hepatocellular carcinoma or borderline lesion?

Adenomatous hyperplasia, defined as a sizable parenchymal nodule in cirrhosis, was examined morphologically, Ninety‐seven nodules of adenomatous hyperplasia were ained from 47 cirrhotic livers and were divided into ‘ordinary’ (44 nodules) and ‘atypical’ (53 nodules) types. The former consisted of hepatocytes similar to those of the surrounding liver, and showed regularly distributed portal tracts. The latter type was composed of hepatocytes showing nuclear atypia, relative to the surrounding liver, and showed irregular or sparse portal tracts. Atypical nodules were histologically heterogen, possessing areas of normo‐trabecular, compact, pseudoglandular and/or scirrhous patterns. Several cytological changes, such as clear cell change, small or large cell change and fatty change, were intermingled variably within a given nodule. Atypical nodules showed expansive and/or replacing growth into the surrounding liver. Atypical hepatocytes also infiltrated into the fibrous septa and portal tracts. Foci of overt hepatocellular carcinoma were found in 11 of the 53 atypical nodules. These findings suggest that ordinary adenomatous hyperplasia may be a large‐sized regenerative nodule, while atypical adenomatous hyperplasia may be a hepatocellular neoplasm, a peculiar form of low‐grade hepatocellular carcinoma or borderline lesion, in which overt hepatocellular carcinoma is likely to evolve through multiple steps.

Delayed MR imaging of the liver: correlation of delayed enhancement of hepatic tumors and pathologic appearance

Abstract.Background: The value of delayed magnetic resonance (MR) imaging (6 min) and ultradelayed MR imaging (1–4 h) for differentiating of hepatic tumors was studied.n Methods: Postcontrast delayed and ultradelayed MR images were obtained after administration of 0.1 mmol/kg of Gd-DTPA in 30 patients with various malignant hepatic tumors.n Results: Delayed enhancement in the center of the tumors was seen in 13 patients on the delayed MR images and in 22 patients on the ultradelayed MR images. On the ultradelayed images, peripheral hypointense rim was seen in 12 patients and central focal hypointense area was seen in eight patients. Pathologically, the portion showing delayed enhancement corresponded to abundant fibrous stroma, the hypointense rim to rich proliferation of tumor cells, and the central hypointense areas to coagulative necrosis.n Conclusion: Ultradelayed MR imaging can characterize different tissue components within various hepatic tumors.

Differentiation of hypervascular hepatic pseudolesions from hepatocellular carcinoma: value of single-level dynamic CT during hepatic arteriography.

PURPOSEnThe purpose of our study was to assess the efficacy of single-level dynamic CT during hepatic arteriography (D-CTA) in the differentiation between hypervascular hepatocellular carcinoma (HCC) and hypervascular pseudolesion.nnnMETHODnD-CTA was performed in nine cases with HCC and nine cases with pseudolesion. Findings on D-CTA were retrospectively analyzed.nnnRESULTSnThe transition of the stain of pseudolesion on D-CTA was divided into three phases: (1) inflow of the contrast material into the portal vein within the lesion, (2) lesion staining, and (3) fading out of the stain; that of HCC was divided into four phases: (1) inflow of CM into tumor, (2) tumor staining, (3) inflow of CM into the adjacent liver, and (4) coronal stain of adjacent liver. The coronal stain was seen in all HCCs but not in any pseudolesions.nnnCONCLUSIONnThe present study suggest that D-CTA is a helpful option in the differentiation between HCC and pseudolesion.

Ciliated hepatic foregut cyst. A mucus histochemical, immunohistochemical, and ultrastructural study in three cases in comparison with normal bronchi and intrahepatic bile ducts.

We describe herein the morphologies of three cases of ciliated hepatic cysts and compare them with those of normal bronchi and intrahepatic bile ducts. Grossly, the hepatic cysts were located in the subcapsular region. They were solitary, unilocular, and rather small (<4 cm in diameter). Histologically, the cyst wall consisted of four layers: pseudostratified ciliated columnar epithelia with mucous cells, subepithelial connective tissue, smooth-muscle bundles, and an outermost fibrous capsule. The epithelial cytoplasm contained neutral, carboxylated, and sulfated mucus. We noted moderate immunoreactivity to keratin, epithelial membrane antigen, carcinoembryonic antigen, DU-PAN-2 and secretory component; weak immunoreactivity to cytokeratin CAM 5.2, cytokeratin AE1 + 3, and carbohydrate antigen 19–9; and faint or negative immunoreactivity to IgA and IgM. Cilia were immunoreactive to actin and tubulin; smooth muscles were immunoreactive to actin and desmin. Ultrastructural observations revealed definite cilia arranged in a 9 + 2 pattern as well as mucous cells. These morphologic features of the hepatic cysts were similar to those of normal bronchi but different from those of normal bile ducts. Our findings suggest that ciliated hepatic cysts arise from the embryonic foregut and differentiated toward bronchial structures in the liver.

Peritumoral rim enhancement of liver metastasis: hemodynamics observed on single-level dynamic CT during hepatic arteriography and histopathologic correlation.

Purpose The purpose of this work was to clarify the mechanism of peritumoral rim enhancement of metastatic liver cancer. Method Twenty-nine liver metastases of colon cancer were examined by single-level dynamic CT during hepatic arteriography, which was performed without table feed. We analyzed these findings and correlated them with the histopathologic findings. Results Eleven metastases were hypervascular and 18 were hypovascular. Early appearance of rim enhancement was seen in 3 of 10 hypervascular metastases and 17 of 18 hypovascular metastases (p < 0.01). The time of appearance and thickness of peritumoral rim enhancement showed no apparent correlation with the desmoplastic reaction or inflammation in the surrounding hepatic parenchyma. Conclusion Two types of intra- and peritumoral enhancement were observed. Peritumoral rim enhancement was considered to be due mainly to the drainage of blood flow from the tumor to the surrounding hepatic parenchyma in hypervascular metastasis or increased arterioportal shunts surrounding the tumor in hypovascular metastasis.

Histopathological and morphometric analysis of atypical adenomatous hyperplasia of human cirrhotic livers

Atypical adenomatous hyperplasia (AAH) is a hyperplastic parenchymal nodular change in the cirrhotic liver, in which overt hepatocellular carcinoma (HCC) occasionally arises. AAH is defined as a sizable hepatocellular nodule with a variable degree of hepatocellular atypia not regarded as HCC, and is different from ordinary adenomatous hyperplasia in which hepatocellular atypia is absent. In the present study, we attempted to evaluate carcinogenetic processes and to find histological variables which indicate malignant transformation in AAH, using 49 surgically resected or autopsied nodules. AAH frequently showed morphological heterogeneity. Atypical lesions within AAHs were divisible into the following three categories from overall histopathological appearances: malignant (A), equivocal (B), or non-malignant (C) lesions. Analysis of combination of these three lesions, which were frequently intermixed in a given AAH, suggested that B lesions appear subsequent to C lesions, and A lesions finally appear in AAH nodules. Among the 14 histological variables, enlargement, hyperchromasia and irregular contour of nuclei were found to correlate well with A lesions. Increased nuclear density, iron resistance, reduction of reticulin fibres, clear cell change, sinusoidal dilatation and presence of abnormal arteries were suggestive of A or B lesions. Nuclear deviation toward the sinusoids, acinar and compact arrangements, fatty change and Mallorys hyaline alone were not useful indicators of A or B lesions. These results indicate that AAH is a preneoplastic or borderline lesion in which overt HCC is likely to evolve through several steps. Although a needle liver biopsy is a useful tool for diagnosis of benign, equivocal and malignant hepatocellular nodular lesions, the needle biopsy specimen should be carefully evaluated by considering the morphological heterogeneity of the AAH and a variable combination of 14 histological variables.

Accumulation of Iodized Oil Within the Non-Neoplastic LiverAdjacent to Hepatocellular Carcinoma via the Drainage Routes of theTumor After Transcatheter Arterial Embolization

AbstractPurpose: After transcatheter arterialnembolization (TAE) with iodized oil (Lipiodol), a relatively densenaccumulation of Lipiodol is often seen in the nontumorous livernadjacent to a hypervascular hepatocellular carcinoma (HCC) nodule. Wencompared this phenomenon with the findings obtained with single-levelndynamic CT during hepatic arteriography (SLDCTHA) and presumed itsnpossible mechanism.nMethods: Fifty-six patients with HCCnunderwent hepatic angiography including SLDCTHA followed by segmentalnor subsegmental TAE with a mixture of an anticancer drug and Lipiodol.nWe compared the drainage area of the HCC depicted on SLDCTHA with thenLipiodol accumulation in the nontumorous liver adjacent to the HCC onnCT after TAE (LpCT).nResults: In 26 of the 56 patients,na definite corona enhancement around the HCC, suggesting the drainagenof blood from the tumor into the surrounding liver parenchyma, was seennon the late phase of SLDCTHA. In 17 of these 26 patients (65.4%), LpCTnshowed a more intense accumulation of Lipiodol in the nontumorous livernadjacent to the HCC that corresponded to the drainage area revealed onnSLDCTHA.nConclusion: The drainage of blood from the HCCnwas considered to be a possible mechanism of the accumulation ofnLipiodol in the nontumorous liver adjacent to the HCC.n