Vascular Sarcomas of Bone

By admin On Oct 17, 2024

Ovid: Oncology and Basic Science

Editors: Tornetta, Paul; Einhorn, Thomas A.; Damron, Timothy A.

Title: Oncology and Basic Science, 7th Edition

> Table of Contents > Section
II – Specific Bone Neoplasms and Simulators > 6 – Bone Sarcomas >
6.6 – Vascular Sarcomas of Bone

6.6

Vascular Sarcomas of Bone

Hannah D. Morgan

Vascular sarcomas of bone are extremely rare tumors for
which the nomenclature is confusing, as there are a myriad of terms in
the literature describing a spectrum of malignant vascular lesions.
There are three major categories: hemangioendothelioma, a low-grade endothelial malignancy of bone; epithelioid hemangioendothelioma, a histologically distinct subgroup of endothelial malignancies; and angiosarcoma, high-grade vascular tumors of bone (Table 6.6-1).
The differential diagnosis, treatment, and prognosis of these lesions
vary according to the age of the patient, anatomic location(s) of
disease, and histologic grade of each tumor.

Pathogenesis

Etiology

A potential predisposing factor is external-beam radiotherapy.

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Table 6.6-1 Comparison of Vascular Sarcomas of Bone

Sarcoma Type	Age	Gender	Anatomic Distribution	Gross Appearance	Histologic Features	Other Details
Hemangioendothelioma	First through ninth decades	M > F (slightly)	Half involve lower extremity; any bone affected	Firm, friable, bloody	Well-formed vascular spaces (“staghorn spaces”) lined by plump endothelial cells. Intermixed with corded pattern mimicking carcinoma.	Multicentricity common; one third of cases multifocal
Epithelioid hemangioendothelioma	Second through eighth decades; peaks in second and third decades	M > F (slightly)	Femur most common; any bone affected	Firm, lobulated, tan	Corded, nested, or stranded pattern of plump endothelial cells with eosinophilic cytoplasm within hyalinized stroma (see Fig. 6.6-1). May form narrow vascular channels. Occasional cytoplasmic vacuoles (represent primitive blood vessel lumina). Signet ring=nlike appearance.
Angiosarcoma	Peaks in fourth decade	M > F (slightly)	Long tubular bones and spine most common; any bone affected	Firm, bloody	Less vasoformative than hemangioendotheliomas. Regions with vascular differentiation and plump malignant endothelial cells. Some areas may show epithelioid appearance.

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Epidemiology

Extremely rare
- <1% of primary bone sarcomas
- Epithelioid sarcomas: <100 cases reported
If the tumor occurs after radiotherapy, the onset is typically several years following completion of the therapy.

Classification

Hemangioendothelioma: low-grade endothelial malignancy of bone
Epithelioid hemangioendothelioma: low- to intermediate-grade endothelial malignancy of bone (Fig. 6.6-1)
Angiosarcoma: high-grade endothelial malignancy of bone

Diagnosis

Clinical Features

Localized pain and occasionally soft tissue swelling
- Angiosarcomas are more likely than others to present with pathologic fracture.
25% to 30% of patients with bony vascular
malignancies present with multicentric disease, either clustered in one
limb or other anatomic location (“skipping joints”) or spread
throughout the skeleton.
- Patient must be questioned about additional sites of bone pain.

Radiologic Features

Lesions may be single or multiple—look for multifocal disease with skeletal survey or bone scan.
Tumors are typically lytic but may be mixed lytic and sclerotic.

May see bony expansion, cortical thinning, or endosteal erosion on plain radiographs or computed tomography (CT) scan

Figure 6.6-1 Metastatic epithelioid hemangioendothelioma. A nodule of tumor has spread within alveolar spaces. (From Rubin E, Farber JL. Pathology, 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 1999.)

Soft tissue mass is not usually a prominent feature of vascular bony malignancies.
Magnetic resonance imaging (MRI) shows marrow involvement and proximity of lesion to neurovascular structures.

Treatment

Surgical Indications and Contraindications

Surgical treatment of vascular bony malignancies depends
on the grade of the lesion (low, intermediate, or high), the anatomic
location of the tumor (whether it is surgically accessible or not), the
size of the lesion, and whether the lesion is solitary or multifocal.

Hemangioendothelioma
- Solitary and accessible: may be cured with surgical resection, with or without adjuvant therapy
- Multifocal: typically treated with radiation therapy
- Bisphosphonates may play a role when bone loss is significant.
Epithelioid hemangioendothelioma
- Unifocal or localized multifocal lesions: should undergo wide resection when possible
- If wide excision is not possible because
  of patient factors or multifocal disease, chemotherapy, radiation
  therapy, and radiofrequency ablation therapy have all been employed.
Angiosarcoma
- Should be resected with a wide or radical surgical margin when disease and patient factors permit
- Surgically inaccessible or multicentric lesions: radiotherapy has been employed
- Effectiveness of chemotherapy has not been proved, although it is commonly used.

Preoperative Planning

Preoperative planning is as for other bone sarcomas (see Chapter 4, Treatment Principles).

Surgical Goals and Approaches

Ideally, lesion should be resected with wide margins.
Bony defect reconstruction (see Chapter 4)

Techniques

Resect and reconstruct according to principles of bone sarcoma surgery (see Chapter 4).
Amputation may be necessary for extensive multifocal disease or for tumors involving major neurovascular structures.

Complications

Same as for all bone sarcomas (see Chapter 4)
Recurrence of tumor

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- Consider adjuvant radiotherapy for close margins.
- Rule out multifocal disease before surgery.

Results and Outcome

Hemangioendothelioma
- Important prognostic variables: degree of tumor differentiation (grade) and multifocality (extent)
  - Multifocal tumors tend to be lower grade with better prognosis.
- Overall the prognosis is good
  - Risk of recurrence: as much as 15%
  - In rare instances, tumor may metastasize.
Epithelioid hemangioendothelioma
- Important prognostic variables: grade and extent (as above)
- Intermediate risk of both local recurrence and metastasis, somewhat greater than that in patients with hemangioendothelioma
Angiosarcoma
- High risk of local recurrence and metastasis
- Long-term survival: 20%

Postoperative Management

The postoperative management of these tumors depends on the type of bony reconstruction performed after surgical resection (see Chapter 4).
Radiation therapy, when indicated, should be started when the wound is
healing satisfactorily, typically about 2 weeks following surgery.