Angiosarcoma of Soft Tissue



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.






Hematoxylin & eosin shows anastomosing vascular structures lined by enlarged, atypical endothelial cells in this well-differentiated 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

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Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Angiosarcoma of Soft Tissue

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