Ultrasound-Guided Percutaneous Thermal Ablation of Hepatic Focal Nodular Hyperplasia——A Multicenter Retrospective Study

Background and Aim: To evaluate the clinical effect of ultrasound (US)-guided percutaneous thermal ablation of hepatic focal nodular hyperplasia (FNH).Methods: A retrospective analysis of the clinical data of patients undergoing US-guided percutaneous thermal ablation of FNH from November 2008 to August 2021 at five medical centers in China was conducted.Results: A total of 53 patients were included (26 males and 27 females). The mean age was 35.1 ± 10.8 years. Sixty-five lesions (46 solitary cases and 7 cases with multiple lesions) were included, 70.8% (46/65) of which were located in the right liver lobe. The mean tumor length was 2.9 ± 1.5 cm. All patients successfully completed the ablation treatment. Immediate postoperative imaging showed that the primary technical success rate was 94.3% (50/53). Two patients underwent ablation 3 and 6 months after the primary ablation, and the secondary technical success rate was 100% (2/2). The incidence of complications was 3.8% (2/53). Imaging follow-up was conducted regularly after ablation, and no residual lesion enlargement or tumor recurrence was observed during the follow-up period. The technique efficacy rate was 98.1% (52/53).Conclusion: US-guided percutaneous thermal ablation is a safe and effective treatment for FNH of the liver.

Differential Diagnosis of Hepatic Mass with Central Scar: Focal Nodular Hyperplasia Mimicking Fibrolamellar Hepatocellular Carcinoma

Fibrolamellar hepatocellular carcinoma is a primary hepatic tumor that usually appears in young adults. Radical surgery is considered curative for this kind of tumor, so early diagnosis becomes essential for the prognosis of the patients. The main characteristic of this entity is the central scar, which is the center of differential diagnosis. We report the case of a 30-year-old man who was diagnosed with fibrolamellar hepatocellular carcinoma by ultrasonography. Contrast-enhanced CT confirmed this diagnosis, and the patient underwent a [18F] fluorocholine PET/CT. Hypermetabolism and the morphology in the nuclear medicine exploration suggest neoplastic nature of the lesion. Radical surgery was performed, and histopathologic analysis was performed, which resulted in focal nodular hyperplasia. Hepatic masses with central scar could have a difficult differential diagnosis, and focal nodular hyperplasia could mimic fibrolamellar hepatocellular carcinoma imaging patterns. These morphofunctional characteristics have not been described in [18F] Fluorocholine PET/CT, so there is a need to find out the potential role PET/CT in the differential diagnosis of hepatic mass with central scar.

Porto-Sinusoidal Vascular Disease and Focal Nodular Hyperplasia-like Nodules in a Patient with Neurofibromatosis and Non-Cirrhotic Portal Hypertension

Introduction/Objective Non-cirrhotic portal hypertension (NCPH) is uncommon. The underlying pathophysiology appears to lie at the level of intrahepatic portal veins and sinusoids, hence the term “porto-sinusoidal vascular disease” (PSVD). We report a rare case of PSVD with focal nodular hyperplasia (FNH)-like nodules in a patient with neurofibromatosis type 2 (NF2). Methods/Case Report A 57-year-old male with NF2 and type 2 diabetes, presented with a large variceal bleed requiring blood transfusion and subsequent transjugular intrahepatic portosystemic shunt (TIPS). Imaging showed a nodular liver, presumed to be cirrhosis due to non-alcoholic liver disease. Liver biopsy was not done. Thereafter, he had several episodes of hepatic encephalopathy and TIPS was downsized to prevent recurrences. The patient required liver transplantation for intractable portal hypertension and severe hepatic encephalopathy; his liver synthetic function was near normal and MELD was 11. Portal vein was patent. The explanted liver was micronodular, soft and weighed 946 grams. Unencapsulated nodules, a few mm to 1 cm in size, were present. Microscopically, there was diffuse nodularity in the absence of bridging fibrosis. Thin, incomplete curvilinear fibrous septa were present. There were aberrant veins, hypervascular portal tracts, herniated portal veins and rare occluded portal veins. Trichrome and reticulin stains confirmed architectural abnormalities including nodularity, lack of bridging fibrosis and approximation of portal tracts. Immunohistochemistry for glutamine synthetase accentuated architectural distortion and revealed nodules with FNH-like geographic areas of staining. Results (if a Case Study enter NA) NA Conclusion This is a rare case of NCPH due to PSVD in a patient with NF2. Microscopy suggested incomplete septal cirrhosis (ISC), a pattern associated with both PSVD and regression of fibrosis in a cirrhotic liver. Isolated portal hypertension without loss of synthetic function favors primary PSVD over regression of fibrosis. FNH-like nodules are consistent with regenerative changes caused by localized abnormalities of blood flow.