# Hepatic Angiomyolipoma With Predominant Lipomatous Component: A Rare Entity

## TL;DR

This paper reports a rare case of a benign liver tumor with mostly fat tissue and some muscle and blood vessel components.

## Contribution

The novelty is the detailed histopathological and immunohistochemical analysis of a hepatic angiomyolipoma with predominant lipomatous features.

## Key findings

- The tumor was predominantly composed of fat with few epithelioid cells and thick-walled blood vessels.
- Immunohistochemistry showed positivity for Melan-A, HMB45, and SMA but negativity for Hep Par1.
- The tumor was confirmed benign with good prognosis following surgical excision.

## Abstract

Hepatic angiomyolipoma (HAML) is a rare benign mesenchymal tumor with varying amounts of mature adipose tissue, smooth muscle cells, and thick-walled blood vessels. We present a rare case of hepatic angiomyolipoma (AML) with predominant lipomatous components. A 42-year-old female presented to the hospital with pain in the right lumbar region. On imaging, there was a large fat-predominant mass attached to the surface of the liver extending down to the lumbar region. On small biopsy, it was reported as a well-differentiated adipocytic neoplasm, and fluorescence in situ hybridization (FISH) studies performed for MDM2 were negative. On excision, histopathological examination showed predominantly fat components, but there were few epithelioid cells between adipocytes and thick-walled blood vessels. These cells were positive for Melan-A, HMB45, and smooth muscle actin (SMA) and negative for hepatocyte paraffin-1 (Hep Par1). Angiomyolipoma is a benign tumor and has a good prognosis with surgical excision. Few cases are associated with tuberous sclerosis.