Biopsies of hepatocellular carcinoma with no reticulin loss: an important diagnostic pitfall

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

Evaluating Liver Biopsies with Well-Differentiated Hepatocellular Lesions

Needle core biopsies of liver lesions can be challenging, particularly in cases with limited material. The differential diagnosis for well-differentiated hepatocellular lesions includes focal nodular hyperplasia, hepatocellular adenoma, and well-differentiated hepatocellular carcinoma (HCC) in noncirrhotic liver, while dysplastic nodules and well-differentiated HCC are the primary considerations in cirrhotic liver. The first part of this review focuses on histochemical and immunohistochemical stains as well as molecular assays that are useful in the differential diagnosis. The second portion describes the features of hepatocellular adenoma subtypes and focuses on the differential diagnoses in commonly encountered clinicopathologic scenarios.

PSMA Immunohistochemistry in Hepatic Neoplasms: A Promising Diagnostic Marker With Potential Theranostic Applications

Accurate classification of well-differentiated hepatocellular neoplasms can be challenging especially in core biopsies. Prostate-specific membrane antigen (PSMA) has been shown to highlight tumor-associated neovasculature in many nonprostatic solid tumors including hepatocellular carcinoma (HCC). Archived 164 hepatectomies and explants with 68 HCCs, 31 hepatocellular adenoma (HA), 24 dysplastic nodules (DN), and 42 metastases were retrieved, and pathologic parameters were evaluated. Sensitivity, specificity, accuracy, positive, and negative predictive values for correct diagnosis of HCC were calculated for PSMA and CD34 immunostains in tissue sections and HCC tissue microarrays. PSMA positivity was defined as capillarized sinusoidal/tumor-associated vessel staining involving ≥5% of the tumor area. In all, 55/68 (80.9%) HCC and 37/42 (88.1%) of liver metastasis were PSMA positive. PSMA was negative in HA, DN, and background liver (100% specificity). CD34 had a 98.5% sensitivity but a 65.5% specificity in identifying HCC. PSMA sensitivity remained high in the HCC tissue microarray (89.7%). PSMA was more accurate than CD34 (95.5% vs. 69.7%) in distinguishing grade 1 HCC from HA and high-grade DN while retaining high sensitivity (80%). The degree of PSMA positivity in HCC was greater in older, male, and human immunodeficiency virus patients ( P <0.05). No associations were found between PSMA staining and other tumor parameters ( P >0.05). PSMA is a marker of neoangiogenesis with increased expression in both primary and metastatic hepatic malignancies. Neovascular PSMA expression is more specific and accurate than CD34 for differentiating HCC from benign and precursor hepatic lesions. Diagnostic and therapeutic utility of PSMA radioligands in malignant liver neoplasms warrant further clinical investigations.

Hepatic Adenomas in Patients 60 and Older Are Enriched for HNF1A Inactivation and Malignant Transformation

Hepatic adenomas occur most commonly in women between the ages of 20 and 40 years, but rarely they occur in older aged persons, including those 60 years of age or older. This group of adenomas, however, has not been systemically examined. Twenty-six hepatic adenomas in persons 60 years of age or older were studied, along with a control group of 50 hepatic adenomas in persons aged 30 to 39. Hepatic adenomas in persons 60 or more years of age were found in 21 women and 5 men, while the control group had 44 women and 6 men. Subtyping the adenomas in persons 60 years or older showed the following results: 18 HNF1A-inactivated adenomas (69%), 4 inflammatory adenomas (15%), and 4 unclassified adenomas (15%). In contrast, the control group showed a significantly different pattern (P=0.003), with a greater percentage of inflammatory adenomas (28, 56%), fewer HNF1A-inactivated adenomas (8, 16%), and more unclassified adenomas (14, 28%). Atypia and malignant transformation within the hepatic adenomas was studied next. Of the hepatic adenomas in persons age 60 or greater, 3 (12%) showed atypical histologic features, and 6 (23%) had a malignant transformation. In contrast, for hepatic adenomas in the control group, only 4 (8%) adenomas showed atypical histologic features, and 3 (6%) had undergone malignant transformation. In addition, the hepatic adenomas that were atypical or showed early malignant transformation were less likely to have beta-catenin activation in patients over 60 (2/9 cases) compared with those between 30 and 39 years (5/7 cases). Myxoid change and heavy lipofuscin deposition were also more common in adenomas in older aged persons. In conclusion, hepatic adenomas in persons 60 years of age or older are enriched for HNF1A-inactivated adenomas and have a higher frequency of malignant transformation. Malignant transformation, however, is less likely to develop through activation of the beta-catenin pathway.