# Primary Hepatic Angiosarcoma: Distinct Imaging Phenotypes Mirroring Histopathologic Growth Patterns in a Retrospective Human Study

## TL;DR

This study shows that the way primary hepatic angiosarcoma appears on imaging closely matches its histologic patterns, helping doctors better understand and diagnose this rare liver cancer.

## Contribution

The study is the first to link specific imaging features of primary hepatic angiosarcoma with distinct histologic growth patterns in humans.

## Key findings

- Mass-forming tumors were found in 76.5% of cases, matching radiologic classifications.
- Non-mass-forming tumors were found in 23.5% of cases and also matched radiologic classifications.
- A significant correlation (p < 0.05) was found between radiologic and histologic classifications.

## Abstract

Background/Objectives: To date, no studies have examined radiologic findings by histologic patterns of primary hepatic angiosarcoma; this study clarified radiologic findings of primary hepatic angiosarcoma according to distinct histologic patterns. Methods: From January 2010 to October 2024, 17 individuals (mean age, 69 years ± 11; 11 men) with pathologically confirmed primary hepatic angiosarcoma underwent computed tomography (CT) with or without magnetic resonance imaging (MRI). Histologic patterns were classified as mass-forming, subdivided into vasoformative and non-vasoformative (epithelioid and spindled) patterns, or non-mass-forming, subdivided into sinusoidal and peliotic patterns. Two radiologists independently reviewed CT and MRI images, classifying lesions as non-mass-forming or mass-forming. Hypervascular portions and targetoid patterns were also assessed. Associations between histologic patterns and radiologic findings were evaluated using Fisher’s exact test. Results: Mass-forming tumors were observed in 13 individuals (76.5%), and non-mass-forming tumors in 4 individuals (23.5%). Significant correlation (p < 0.05) was found between radiologic classification (non-mass-forming or mass-forming) and corresponding pathologic patterns. Pathologic subdivision into vasoformative and non-vasoformative patterns did not correlate with hypervascular portions on imaging. Conclusions: Pathological classification into mass-forming and non-mass-forming patterns corresponds closely to radiologic classification of mass-forming and non-mass-forming lesions, indicative of strong pathologic features in imaging.