Hemangiopericytoma

Cyril Fisher, MD, DSc, FRCPath

Key Facts

Terminology

Tumor with diffuse pattern of branching, dilated, thin-walled blood vessels composed of short spindle cells
Many tumor types have pericytomatous pattern, so diagnosis is rarely made
Most such tumors without specific differentiation are now classified as solitary fibrous tumors

Clinical Issues

Site: Pelvis, retroperitoneum, proximal limbs
Subset in meninges
Subset in sinonasal region

Microscopic Pathology

Widespread hemangiopericytic pattern
Thin-walled vessels
Short plump spindle cells

Hematoxylin & eosin shows a diffuse hemangiopericytic pattern. The vascular channels are dispersed throughout the tumor but vary in size, shape, and dilatation. Note the “staghorn” shape

Hematoxylin & eosin shows hemangiopericytoma with myxoid change. There is a hemangiopericytic pattern, but the vessels are slit-like

, not dilated.

TERMINOLOGY

Abbreviations

Hemangiopericytoma (HPC)

Definitions

Tumor with diffuse pattern of branching, dilated, thinwalled blood vessels composed of short spindle cells
Diagnosis is now rarely made
- Many different specific tumor types have hemangiopericytic vascular pattern
- Most remaining tumors without specific differentiation are now classified as solitary fibrous tumor
Tumors of pericytes now classified as myopericytoma

CLINICAL ISSUES

Epidemiology