Angiosarcoma of Soft Tissue
Thomas Mentzel, MD
Key Facts
Terminology
Malignant mesenchymal neoplasm of cells recapitulating variably morphologic and functional features composed of endothelial cells
Clinical Issues
Deep soft tissues
Lower extremities, followed by upper extremities
Trunk > head and neck
Significant proportion intraabdominal and retroperitoneal
Rare (more frequent in superficial locations)
< 1% of all sarcomas
Any age but most common in older adults
Poor prognosis irrespective of grade of malignancy
5-year survival 20-30% at best
Aggressive surgical resection with wide tumor-free margins
Microscopic Pathology
Irregular, anastomosing vascular spaces
Variably pleomorphic endothelial tumor cells
Endothelial multilayering and papillary formation
Solid areas common
No complete rim of actin(+) (myo)pericytes
Often intracytoplasmic lumina
Prominent nuclear atypia
Numerous mitoses
Expression of endothelial markers
Epithelioid angiosarcomas occur relatively frequent in deep soft tissues
Solid sheets of large epithelioid cells in epithelioid angiosarcoma
Gross pathology shows an ill-defined hemorrhagic neoplasm in deep soft tissue, a rare location for angiosarcoma. |
TERMINOLOGY
Synonyms
Hemangiosarcoma
Hemangioblastoma
Malignant hemangioendothelioma
Definitions
Malignant mesenchymal neoplasm of cells recapitulating variably morphologic and functional features composed of endothelial cells
ETIOLOGY/PATHOGENESIS
Developmental Anomaly
Develops rarely in association with genetic syndromes
Klippel-Trenaunay syndrome
Maffucci syndrome
Environmental Exposure
Rarely develops adjacent to foreign material or synthetic vascular grafts
CLINICAL ISSUES
Epidemiology
Incidence
Rare
< 1% of all sarcomas
More frequent in superficial locations
1/4 of angiosarcomas arise in deep soft tissues
Age
Occur at any age but most common in older adults
Very rare in childhood
Gender
M > F
Site
Deep soft tissues
Lower extremities > upper extremities
Trunk > head/neck region
Significant proportion arises in abdomen and retroperitoneum
Rarely multifocal
Presentation
Slow growing
Deep mass
Usually large mass
Hematologic abnormalities
Thrombocytopenia may be present
Arteriovenous shunting may be present
Rarely arise in nonlipogenic component of dedifferentiated liposarcomas
Rarely arise in benign or malignant nerve sheath tumors
Very rarely arise in preexisting benign hemangioma
Treatment
Surgical approaches
Aggressive surgical resection with wide tumor-free margins
Adjuvant therapy
Response to chemotherapy
Inhibition of angiogenesis
Prognosis
Poor prognosis irrespective of grade of malignancy
Local recurrence in 20-30%
Distant metastases in 50%
5-year survival 20-30% at best
MACROSCOPIC FEATURES
General Features
Infiltrating neoplasm
Areas of hemorrhage
MICROSCOPIC PATHOLOGY
Histologic Features
Angiosarcoma
Usually no relationship to preexisting vessels
Irregular infiltrating vascular spaces
Anastomosing vascular spaces
Variably pleomorphic endothelial tumor cells
Endothelial multilayering
Endothelial papillary formations
Solid areas common
Neoplastic vascular structures encircled by reticulin fibers
No complete rim of actin(+) (myo)pericytes
Often intracytoplasmic lumina
Lumina may contain erythrocytes
Prominent nuclear atypia
Numerous mitoses
Areas of hemorrhage and necrosis may be present
Rare predominantly spindle cell morphology
Clear distinction between lymphatic and vascular differentiation remains problematic
Epithelioid angiosarcoma
More frequent in deep soft tissues
Often rapid growth
Very aggressive clinical course
Solid sheets of large epithelioid cells
Tumor cells with abundant eosinophilic cytoplasm and large vesicular nuclei
Prominent cytologic atypia
Numerous mitoses
Often areas of tumor necrosis
Rare granular cell variant
Rare inflammatory variant
Predominant Pattern/Injury Type
Diffuse
Predominant Cell/Compartment Type