Surgical Pathology Diagnostic Pitfalls of Hepatoblastoma

Abstract

Hepatoblastoma (HB) is the most common malignancy within the rare cohort of pediatric primary liver tumors. It may arise sporadically or in association with germline mutations in specific genetic syndromes. Histogenesis recapitulates fetal hepatic development, however, this tumor can exhibit a markedly heterogeneous appearance both macroscopically and under the microscope. Histologic subtypes are classified based on morphologic appearance, with additional discrimination based on emerging molecular and immunohistochemical features. Numerous diagnostic pitfalls exist from clinical presentation through to ancillary testing; at all stages, the surgical pathologist must be discerning and open to collaboration with colleagues of different specialties. Problematic areas include the adequacy of tissue sampling, correlation of histology with radiologic appearance and alpha feto-protein (AFP) serology, forming a diagnostic consensus within the pediatric pathology community and choosing a shrewd immunohistochemical panel. This review discusses the sequence of events leading up to histologic assessment, and the nuances of microscopic evaluation. Along the way, pitfalls are highlighted, providing a tool for the surgical pathologists to support their individual approach.

Liver Biopsy Handling of Metabolic-Associated Fatty Liver Disease (MAFLD): the Children’s Hospital of Eastern Ontario grossing protocol

“…The liver biopsy is a paramount procedure in internal medicine and gastroenterology, aiming to identify a broad spectrum of etiologies ranging from abnormal values of liver function tests to structural changes or injuries at the hepatocellular level. 1 – 5 Clinical evaluation entails a range from asymptomatic individuals to acute liver failure prompting liver transplantation. In the most recent definition of acute hepatitis, the American Association for the Study of Liver Disease categorizes an acute increase of liver biochemical values within six months of onset in a patient apparently not showing a pre-existing liver disease, while if the threshold of 6 months is over, the definition of chronic hepatitis is in place.…”

Computed tomography imaging phenotypes of hepatoblastoma identified from radiomics signatures are associated with the efficacy of neoadjuvant chemotherapy

“…Furthermore, the heavily vascularized tumors make it difficult to perform a needle biopsy. In addition being a heterogenous tumor, hepatoblastoma has different compounds and various biologic behaviors [ 9 ]; a needle biopsy may not represent the heterogeneity of the tumor.…”

The Role of N6-Methyladenosine in the Promotion of Hepatoblastoma: A Critical Review

“…Hepatoblastoma (HB) is a rare and heterogeneous malignancy deriving from embryonic liver parenchyma. Despite affecting fewer than two children in a million, it represents Cells 2022, 11, 1516 2 of 14 over a third of primary tumors of the pediatric liver [1][2][3][4]. Its genesis and progression are highly genetically mediated, indicated by sporadic forms adjacent to a strong syndromic association, but also intimately associated with the frequent occurrence of extramedullary hematopoiesis, as identified in early studies on the developing intrahepatic biliary system of the fetal liver [5].…”

“…Due to the architectural and cytological complexity of tumors, and compounded by their rarity, consensus between experts is not always established. This is particularly observed amongst subtypes such as small cell undifferentiated, which unfortunately traverses a less favorable clinical course [2,4,6]. The 5-year survival rate of patients with HB approaches 80% due to advances in early detection and multidisciplinary therapy, however, it remains challenging to predict the clinical course.…”