Radiological and histopathological manifestations of hepatocellular nodular lesions concomitant with various congenital and acquired hepatic hemodynamic abnormalities

Benign pericholecystic regeneration mimicking hepatocellular carcinoma: a potential pitfall in imaging of cirrhosis

Several pseudolesions mimicking malignancy have been reported in cirrhotic and non-cirrhotic livers. Pericholecystic regeneration is among those pseudolesions and can occasionally mimic malignancy. Herein we present a case series comprised of 10 cirrhotic patients (majority due to alcoholic liver disease [ALD] or metabolic dysfunction associated steatotic liver disease [MASLD]) with pericholecystic observations initially categorized as highly suspicious for HCC (LR-4 and LR-5) due to their suspicious enhancement pattern which were later proven to be benign based on biopsy, transplantation or imaging criteria (stability of size and morphology on serial CT or MRI for > 2 years). These observations ranged 2-6.3 cm in size, were multiple in most patients and universally resulted in indentations of gallbladder. Arterial phase hyperenhancement and washout, features usually attributed to hepatocellular carcinoma (HCC), were seen in most patients. However, ancillary features of malignancy such as diffusion restriction, increased T2 signal, and hypointensity on hepatobiliary phase MRI were not present. Pericholecystic observations, in particular in the setting of ALD and MASLD, should be carefully assessed and possibility of pseudolesion should be considered especially when the observations are multiple, cause indentation of gallbladder, and lack ancillary features of malignancy.

Hepatocellular nodules in vascular liver diseases

Hepatocellular nodules have been recognized in vascular liver diseases for a long time and mostly described and studied in the imaging literature. Some confusions in their identification and overlap in their definitions exist, especially in this specific clinical context. Pathology descriptions report the development of nodular regenerative hyperplasia, large regenerative nodule, and focal nodular hyperplasia, as adaptive responses of the liver parenchyma to the modified blood flow. True neoplastic hepatocellular nodules such as hepatocellular adenoma and hepatocellular carcinoma can also appear, mainly in Budd-Chiari syndrome, and have to be correctly diagnosed. This is more difficult for the radiologist in these diseased livers, leading more frequently to perform liver biopsies. We describe the histology of each type of well-differentiated hepatocellular nodules and provide some clues for their differential diagnosis. A review of the literature gives an historical perspective of the problem and enlightens the frequency and the subtypes of hepatocellular nodules found in the most common vascular liver diseases.

Hepatocellular nodules expressing markers of hepatocellular adenomas in Budd-Chiari syndrome and other rare hepatic vascular disorders

BACKGROUND & AIMS

A broad range of hepatocellular nodules has been reported in hepatic vascular disorders. It is not clear whether hepatocellular adenoma (HCA) in this context share the same characteristics as conventional HCA. The aim of this study was to carry out a retrospective multicenter survey of hepatocellular nodules associated with hepatic vascular disorders.

METHODS

Forty-five cases were reviewed, including 32 Budd-Chiari syndrome (BCS). Benign nodules were subtyped using the HCA immunohistochemical panel.

RESULTS

Nodules with a HCA morphology were observed in 11 cases. Six originated in BCS: two were liver fatty acid binding protein (LFABP) negative (one with malignant transformation); two expressed glutamine synthetase (GS) and nuclear b-catenin, two expressed C reactive protein (CRP). Among three cases with portal vein agenesis, one nodule was LFABP negative, two expressed GS and nuclear b-catenin, both with malignant transformation. In a Fallot tetralogy case, there were multiple LFABP negative nodules with borderline features and in a hepatoportal sclerosis case, the nodule looked like an inflammatory HCA. Two additional cases had nodules expressing CRP, without typical characteristics of inflammatory HCA.

CONCLUSION

HCA of different immunohistochemical phenotype can develop in hepatic vascular disorders; they may have a different behavior compared to conventional HCA and be more at risk of malignant transformation.

Serum Amyloid A-Positive Hepatocellular Neoplasm: A New Type of Tumor Arising in Patients with Advanced Alcoholic Disease

This chapter reviews a new type of hepatocellular neoplasm, serum amyloid A-positive hepatocellular neoplasm (SAA-HN), which arises in patients with advanced alcoholic liver disease such as cirrhosis. SAA-HNs share histological and immunohistochemical features with inflammatory hepatocellular adenoma, for example, a strong immunoreactivity for SAA. Clinicopathological features and issues regarding SAA-HN are reviewed with emphasis regarding its potential to develop into hepatocellular carcinoma.

Hepatocellular adenoma management: advances but still a long way to go

Hepatocellular adenomas (HCAs) are composed of four molecular subgroups: mutations inactivating the HNF1A gene; the inflammatory phenotype with mutations of different genes leading to STAT3 activation; the activation of β-catenin by mutations in exon 3; among β-HCA, half display both inflammatory and β-catenin-activated phenotypes; and the unclassified tumors. The identification of these subtypes by MRI and immunohistochemistry on tissue is considered as a major criterion to manage patients. Of particular relevance is the identification of the β-catenin-mutated group due to its high risk of malignant transformation. In spite of this progress, the classification has not gained recognition among surgeons. It is hoped that by working as a multidisciplinary team, including surgeons, radiologists, pathologists and molecular biologists, patients will be managed more rationally. In this article, we will present known and new data, well accepted and that which is still controversial. The progress made in the field of HCA in the last 12 years, whether in epidemiology, diagnosis (clinical, pathology, imaging) or management, is related in one way or another to molecular advances.

Pathological Diagnosis of Hepatocellular Cellular Adenoma according to the Clinical Context

In Europe and North America, hepatocellular adenomas (HCA) occur, classically, in middle-aged woman taking oral contraceptives. Twenty percent of women, however, are not exposed to oral contraceptives; HCA can more rarely occur in men, children, and women over 65 years. HCA have been observed in many pathological conditions such as glycogenosis, familial adenomatous polyposis, MODY3, after male hormone administration, and in vascular diseases. Obesity is frequent particularly in inflammatory HCA. The background liver is often normal, but steatosis is a frequent finding particularly in inflammatory HCA. The diagnosis of HCA is more difficult when the background liver is fibrotic, notably in vascular diseases. HCA can be solitary, or multiple or in great number (adenomatosis). When nodules are multiple, they are usually of the same subtype. HNF1 α -inactivated HCA occur almost exclusively in woman. The most important point of the classification is the identification of β -catenin mutated HCA, a strong argument to identify patients at risk of malignant transformation. Some HCA already present criteria indicating malignant transformation. When the whole nodule is a hepatocellular carcinoma, it is extremely difficult to prove that it is the consequence of a former HCA. It is occasionally difficult to identify HCA remodeled by necrosis or hemorrhage.

Perfusion and parenchymal changes related to vascular alterations of the liver

Imaging plays a significant role in the diagnosis of vascular abnormalities of the liver and sometimes provides the only clue to the correct diagnosis. With advances of imaging techniques and multiphasic acquisition of liver imaging, various perfusion changes are frequently encountered. Correct imaging diagnosis of significant vascular diseases can prompt appropriate work-up and timely management. Accurate differentiation of clinically insignificant perfusion phenomena from clinically significant findings including neoplastic conditions and in the setting of post-transplantation is essential. This pictorial essay illustrates various perfusion and parenchymal changes associated with portal venous inflow, hepatic venous outflow, and non-portal venous third inflow and describes brief background pathophysiology and differential points.

That liver lesion on MDCT in the oncology patient: is it important?

Multidetector-row computed tomography (MDCT) has become the primary imaging test for the staging and follow-up of most malignancies that originate outside of the central nervous system. Technical advances in this imaging technique have led to significant improvement in the detection of metastatic disease to the liver. An unintended by-product of this improving diagnostic acumen is the discovery of incidental hepatic lesions in oncology patients that in the past remained undetected. These ubiquitous, incidentally identified hepatic lesions have created a management dilemma for both clinicians and radiologists: are these lesions benign or do they represent metastases? Naturally, the answer to this question has profound prognostic and therapeutic implications. In this review, guidelines concerning the diagnosis and management of some of the more common hepatic incidental lesions detected in patients with extrahepatic malignancies are presented.

Hepatic incidentalomas

Recent advances in multidetector-row computed tomography, magnetic resonance imaging, and ultrasonography have led to the detection of incidental hepatic lesions in both the oncology and nononcology patient population that in the past remained undiscovered. These incidental hepatic lesions have created a management dilemma for both clinicians and radiologists. In this review, guidelines concerning the diagnosis and management of some of the more common hepatic incidentalomas are presented.