Vascular tumors of intermediate malignancy: An update

Area of Science:

• Vascular Oncology
• Pathology
• Genetics

Background:

• Hemangioendothelioma represents a spectrum of endothelial neoplasms.
• These rare tumors exhibit intermediate malignancy, distinct from benign hemangiomas and malignant angiosarcomas.

Purpose of the Study:

• To review and delineate the distinct clinicopathologic and genetic entities within the hemangioendothelioma classification.
• To provide a comprehensive overview of the clinical, morphologic, immunohistochemical, and genetic features of each subtype.
• To discuss the differential diagnosis for these rare endothelial neoplasms.

Main Methods:

• Literature review of hemangioendothelioma subtypes.
• Analysis of clinical, morphologic, immunohistochemical, and genetic data.
• Comparative review of distinct hemangioendothelioma entities.

Main Results:

• Hemangioendotheliomas encompass several distinct entities: epithelioid, kaposiform, papillary intralymphatic angioendothelioma, retiform (hobnailed), pseudomyogenic, composite, and YAP1::TFE3-fused hemangioendothelioma.
• Each subtype exhibits unique clinicopathologic and genetic characteristics.
• Understanding these features is crucial for accurate diagnosis and management.

Conclusions:

• Hemangioendothelioma is a heterogeneous group of rare endothelial tumors.
• Accurate classification requires integrating clinical, morphologic, immunohistochemical, and genetic findings.
• This review provides a framework for differentiating these entities and guiding diagnostic approaches.