The pathological evaluation of hepatic vascular lesions in children requires special consideration. Inconsistent terminology, rarity of pathology specimens and overlapping pathological features between various lesions may pose a serious diagnostic challenge. In this review, we highlight the importance of using the International Society for the Study of Vascular Anomalies (ISSVA) classification scheme to characterise these lesions. Selected entities are discussed, including hepatic vascular tumours exclusively seen in the paediatric age group, hepatic infantile haemangioma and hepatic congenital haemangioma. Vascular malformations, with emphasis on their syndromic associations (venous malformation in blue rubber bleb naevus syndrome) and complications (hepatocellular nodules in Abernethy malformation) are also covered.

Congenital portosystemic shunts (CPSSs) are rare vascular anomalies characterized by abnormal connections between the portal/splanchnic veins and the systemic veins. CPSSs often occur as an isolated congenital anomaly, but they can also coexist with congenital heart disease (CHD). Owing to their myriad consequences on multiple organ systems, familiarity with CPSS is of tremendous importance to the care of patients with CHD. The rationale and timing for interventions to embolize CPSS in this scenario are discussed. Specific shunt embolization techniques are beyond the scope of this article.

Abernethy malformation or congenital extrahepatic portosystemic shunt is an extremely rare condition whereby the portomesenteric blood drains into a systemic vein and bypasses the liver through a complete or partial shunt. Severe complications include hyperammonemia and encephalopathy, benign and malignant liver tumors, and hepatopulmonary syndrome. We describe a case where a female adult diagnosed with congenital extrahepatic portosystemic shunt subsequently developed focal nodular hyperplasia and then hepatocellular carcinoma.

Congenital portosystemic shunts (CPSS) or congenital extrahepatic portosystemic shunts (CEPS) is a rare malformation. This congenital anomaly presents with a diverse array of clinical manifestations, ranging from asymptomatic to severe complications such as cardiac failure, pronounced pulmonary hypertension, and widespread pulmonary arteriovenous malformations. CPSS increases the risk of developing benign or malignant liver tumors, including nodular regenerative hyperplasia, focal nodular hyperplasia, hepatic adenoma, hepatocellular carcinoma, and hepatoblastoma. We report a case of a 15-month-old boy, identified with Abernethy\'s malformation type Ib, who presented with an abdominal mass during a follow-up. A comprehensive assessment established a diagnosis of hepatoblastoma. The patient was transferred to a specialized liver transplant center for further treatment and management. This is a review of literature highlighting the complexity of Abernethy malformation and its associated risk of liver tumors.

Abernethy malformation is a congenital extra-hepatic porto-systemic shunt. This malformation is characterized by an abnormal connection between the portal vein or its branches and one of the systemic veins. Though rare, this anomaly can lead to pulmonary hypertension. Drainage of Abernethy malformation into coronary sinus is extremely rare. We describe a child with Abernethy malformation with unusual drainage into coronary sinus. The abnormal channel was successfully closed by trans-catheter technique with normalisation of pulmonary arterial pressures.

BACKGROUND: Abernethy malformation, also known as congenital extrahepatic portosystemic shunt, is an uncommon malformation resulting from aberrant development of the portal venous system. Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene. It mainly affects the exocrine glands of the respiratory, digestive and reproductive systems. It is considered extremely rare in the Asian population. We present a clinical case involving a pediatric patient of Asian descent who was diagnosed with Abernethy malformation and CF.
METHODS: A 12-year-old girl presented with a medical history of recurring respiratory infections and hemoptysis, and chest computed tomography (CT) showed bronchiectasis. Whole exome sequencing was performed for the patient, yielding findings that revealed a compound heterozygous variant of the CFTR gene: c.233_c.234insT/p.Trp79fsTer3 (maternal origin); c.2909G>A/p.Gly970Asp (paternal origin). CF was diagnosed. The physician\'s attention was drawn to the presence of splenomegaly during disease progression. Abdominal enhanced CT revealed splenomegaly, compression of the left kidney, and multiple tortuous dilated vascular shadows were seen at the splenic hilum, which flowed back into the left renal vein and portal vein, suggesting Abernethy malformation type II. Intraoperatively, the abnormal blood flow was seen to merge into the inferior vena cava through the left renal vein without hepatic processing, and the pathology of liver biopsy showed hypoplastic, dilated or absent portal vein branches, both of which supported the diagnosis of Abernethy malformation type II. This represents the initial documented instance of Abernethy malformation accompanied by a CFTR gene mutation in the existing body of literature.
CONCLUSIONS: Coexisting Abernethy malformation and CF are rare. Detailed medical history information, abdominal enhanced CT, venography and genetic testing contribute to diagnosis as well as differential diagnosis.

Hepatocellular nodules can develop in the setting of chronic hepatic vascular disorders including those characterized by portosystemic shunts such as Abernethy malformation and post-Fontan procedure. The nodules can range from benign lesions such as regenerative nodules, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA) to malignant neoplasms such as hepatocellular carcinoma (HCC). In many instances, these nodules are difficult to place into well-defined categories based on radiologic or histologic features. Nodular lesions that resemble FNH are common in this context and have been described as FNH-like nodules, the nature of which is not well-established. This study examines 6 liver resections from patients with vascular disease characterized by portosystemic shunts. A wide range of nodules were present in these cases, including regenerative nodules (n = 2), FNH and FNH-like (n = 30), HCA (n = 10), HCA-like (n = 13), and HCC (n = 2). Six nodules from 3 patients were categorized as FNH-like due to one or more features such as nodular architecture, fibrous septa, and ductular reaction, but lack of typical map-like glutamine synthetase (GS) staining. Further characterization of these 6 FNH-like nodules showed diffuse GS staining in all nodules (3 diffuse homogeneous, 3 diffuse heterogeneous). Targeted next-generation sequencing identified CTNNB1 alterations in all tested FNH-like nodules (n = 4). These results indicate that FNH-like nodules in the setting of chronic hepatic vascular disorders can be neoplastic. Since the presence of β-catenin activation portends a potential risk for malignant progression, GS and β-catenin immunohistochemistry should be obtained in all cases showing FNH-like morphology, with molecular analysis performed in cases with indeterminate staining pattern.

BACKGROUND: Abernethy malformation is a rare congenital vascular malformation with a portosystemic shunt that may clinically manifest as cholestasis, dyspnea, or hepatic encephalopathy, among other conditions. Early diagnosis and classification are very important to further guide treatment. Typically, patients with congenital portosystemic shunts have no characteristics of portal hypertension. Herein, we report an 18-year-old female with prominent portal hypertension that manifested mainly as rupture and bleeding of esophageal varices. Imaging showed a thin main portal vein, no portal vein branches in the liver, and bleeding of the esophageal and gastric varices caused by the collateral circulation upwards from the proximal main portal vein. Patients with Abernethy malformation type I are usually treated with liver transplantation, and patients with type II are treated with shunt occlusion, surgery, or transcatheter coiling. Our patient was treated with endoscopic surgery combined with drug therapy and had no portal hypertension and good hepatic function for 24 mo of follow-up.
METHODS: This case report describes our experience in the diagnosis and treatment of an 18-year-old female with Abernethy malformation type IIC and portal hypertension. This condition was initially diagnosed as cirrhosis combined with portal hypertension. The patient was ultimately diagnosed using liver histology and subsequent imaging, and the treatment was highly effective. To publish this case report, written informed consent was obtained from the patient, including the attached imaging data.
CONCLUSIONS: Abernethy malformation type IIC may develop portal hypertension, and traditional nonselective beta-blockers combined with endoscopic treatment can achieve high efficacy.

The Abernethy malformation is an extremely rare congenital, extrahepatic, portosystemic shunt. There are many problems associated with this abnormal portovenous shunting and subsequent reduced hepatic portal venous flow. With the advances in non-invasive imaging technologies, these cases are diagnosed in more numbers; however, the presentation of patients is varied and the natural history is not completely known. The presenting symptom of the portosystemic shunt is mainly hyperammonemia, leading to encephalopathy. Management varies depending on the type of shunt and its clinical course; hence, the classification of the congenital portosystemic shunt is important in these patients.

Abernethy malformation (congenital extrahepatic portosystemic shunt [CEPS]) is rare and is characterized by an aberrant connection between the portal and systemic veins, bypassing the liver. It can have varying presentations and can lead to severe complications if left untreated. It is usually diagnosed incidentally on abdominal imaging. Occlusion venography and measurement of portal pressures (pre- and postocclusion) is an important step in management. Complete occlusion of the malformation in cases where the portal veins in the liver are very small and the gradient is more than 10 mm Hg, can potentially lead to acute portal hypertensive complications, such as porto-mesenteric thrombosis. We report a case of Abernethy malformation diagnosed on an abdominal computed tomography scan that presented with neurological symptoms and was successfully managed by interventional radiology via endovascular closure through placement and sequential occlusion of 2 metal stents.