Imaging and Pathological Feature Analysis of Idiopathic Portal Hypertension
Authors: Li Hanyu , Gong Ling , Yang Wenjun , Tao Mengyao , Cao Boyu , Tang Dong 
Published: August 2024

Background: Idiopathic portal hypertension (IPH) is a rare clinical condition often misdiagnosed as cirrhosis. The management of IPH focuses on preventing and treating complications related to portal hypertension, such as bleeding from esophagogastric fundal varices. In contrast, the management of cirrhosis focuses on symptomatic treatment based on etiology, protecting hepatocyte function, and inhibiting hepatic inflammation and fibrosis. Therefore, it is crucial to correctly recognize both diseases and take appropriate therapeutic measures. Objectives: The aim of this study was to summarize and analyze the imaging, pathological, and serological features of idiopathic portal hypertension and cirrhosis to reduce misdiagnosis in clinical practice. Patients and Methods: Pathological, radiological parameters [computed tomography (CT)/magnetic resonance imaging (MRI)], and serological examinations were retrospectively evaluated for 14 patients with IPH and 30 patients with cirrhosis. We analyzed and compared their imaging manifestations in terms of spleen thickness and length, liver morphology, hepatic lobe atrophy, hyperplasia, portal vein thrombosis, arteriovenous phase liver perfusion, regenerative nodules, focal nodular hyperplasia-like lesions of the liver, portal vein morphology, splenorenal shunt, and hepatorenal shunt. The aim was to investigate the correlation between the imaging manifestations and the pathological manifestations. Results: There were significant differences between the IPH and cirrhosis groups in individual indicators of liver function, routine blood tests, and coagulation function (P < 0.05). Significant differences in spleen thickness and length were also observed between the IPH and cirrhosis groups (P < 0.05). Atrophy and hyperplasia of the hepatic lobe differed between the two groups. Changes in liver morphology and parenchyma were observed in both the IPH and cirrhosis groups, with diffuse regenerative nodules and focal nodular hyperplasia-like lesions being significant for distinguishing between IPH and cirrhosis. Focal nodular hyperplasia-like lesions were more common in patients with idiopathic portal hypertension, whereas diffuse regenerative nodules were more common in patients with cirrhosis. All 14 IPH patients had abnormalities in the portal vein system, including main portal vein dilation, stiffness, straightening, and distal branch vein stenosis or occlusion, while 9 cirrhosis patients had portal vein abnormalities, primarily thinning of the portal vein. Pathology revealed that patients in the cirrhosis group had varying degrees of cell necrosis and edema, and pseudolobule formation was observed in all patients. Patients with IPH showed varying degrees of fibrosis in the portal and confluent areas, but lobular inflammation was not evident. Some IPH patients experienced portal vein occlusion and stenosis. Conclusion: Idiopathic portal hypertension is relatively rare in clinical practice and is characterized by mostly normal liver function and hypersplenism, which may lead to a decrease in platelets, red blood cells, and white blood cells. If a giant spleen is found on imaging and the liver surface is smooth, IPH should be considered. Additionally, fibrosis, stenosis, and occlusion of the portal venous system, as well as focal nodular hyperplasia-like lesions, are suggestive of idiopathic portal hypertension. In contrast, diffuse regenerative nodules and pseudolobule formation are often indicative of cirrhosis. Furthermore, atrophy and hyperplasia of the liver are significant in differentiating the two diseases.