What are the classifications of hepatic hemangiomas in adults?

In general, adult hepatic hemangiomas are primarily classified according to pathology and morphology into cavernous hemangioma, sclerosing hemangioma, epithelioid hemangioma, capillary hemangioma, and endothelial cell hemangioma. The specific classifications are as follows:

1. Cavernous hemangioma: This is the most common type among adult hepatic hemangiomas. Pathologically, it features numerous dilated thin-walled vascular spaces filled with blood, separated by fibrous tissue, giving a sponge-like appearance. These hemangiomas are usually solitary but can also be multiple, ranging in diameter from several millimeters to tens of centimeters. They grow slowly, and most patients are asymptomatic, with the lesion often discovered incidentally during routine physical examination.

2. Sclerosing hemangioma: Characterized by narrowed or occluded vascular lumina and extensive proliferation of fibrous tissue, resulting in a firm tumor texture. Microscopically, there is a reduction in vascular spaces and an increase in fibrous strands, with possible calcification in some areas. Growth is even slower, and these tumors are typically small, causing minimal compression on surrounding liver tissue and rarely producing symptoms.

3. Endothelial cell hemangioma: Composed of proliferating vascular endothelial cells that are uniformly shaped and arranged in single or multiple layers, forming tubular or slit-like structures. Most cases are benign, although a few may exhibit locally aggressive growth. Larger tumors may compress adjacent liver tissue.

4. Capillary hemangioma: Consists of tiny capillaries with small-diameter vascular lumina and markedly proliferative, tightly packed endothelial cells. This type is rare in adults and usually presents as a single small lesion less than 1 cm in diameter. It shows no significant growth tendency and generally requires no specific treatment—regular follow-up is sufficient.

5. Epithelioid hemangioma: Composed of epithelioid endothelial cells that are polygonal or round with abundant cytoplasm; vascular lumina are poorly defined or appear slit-like. Clinically rare, some cases may be associated with inflammatory reactions.

In clinical practice, management strategies are determined based on the hemangioma type, size, location, and patient symptoms. Most small, asymptomatic lesions require only periodic ultrasound monitoring, while larger or symptomatic lesions may require interventional or surgical treatment.