Spindle Cell Hemangioendothelioma

Introduction

Spindle cell hemangioendotheliomas, also known as spindle cell hemangiomas, were first described in 1986 as low-grade angiosarcomas. These tumors present as non-tender, slow-growing subcutaneous nodules that commonly recur following excision. More recently, these tumours have been labelled as benign vascular tumours. We present the natural history of 1 case over 43 years.

Case Report

In 1989, a 33-year-old otherwise healthy patient presented to our clinic with a mass on his left posterior upper back present since childhood. He had previously gone through 3 surgical debulking of the mass between 1973 and 1989 before his referral to plastic surgery. All previous attempts at debulking the mass led to recurrence. Previous pathology reports indicated that the tumour was a spindle cell hemangioendothelioma. At the time of presentation to our clinic, the tumour was non-tender and did not limit him functionally. The patient did not have any signs of malignancy.

On examination, the mass measured 10 cm × 15 cm. It was diffuse, firm, non-tender, multilobulated, involved muscle and was fixed to the chest wall. A computed tomography (CT) scan revealed a large multinodular lesion infiltrating a large part of the skin and subcutaneous fat, the latissimus muscle, soft tissue between the ribs, and the erector spinae muscle. Several nodules were felt to be recurrences of the original growth. There was no evidence of distant metastases.

In 1989, spindle cell hemangioendotheliomas were thought to be a form of soft tissue sarcoma, with a low risk of metastases. Radical resection was suggested for these tumours. With the patient’s history of multiple recurrences, our plastic surgery team in conjunction with thoracic surgery felt that a wide radical excision would be the best course of action. The patient declined surgery, given recurrence of the tumour was a strong possibility.

In 1995, CT and magnetic resonance imaging (MRI) showed a modest progression of tumour growth over 6 years. The nodules abutted the paraspinal muscles and extended laterally through the intercostal muscles at the level of the spleen. More recent literature suggested no malignant potential for hemangioendotheliomas supporting continued non-surgical management. ^1,2

In 2015, a repeat CT and MRI confirmed significant change from previous imaging and no evidence of metastases or local invasion suggestive of invasive cancer (Figure 1). The mass had doubled over 20 years (Figures 2 and 3). The mass continued to have no functional implications for the patient.

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Figure 1.

Posterior–anterior view of the chest using contrast-enhanced computerized tomography. There are multiple soft tissue nodules ranging in size from 1 to 2.5 cm and extending over an area of 12 cm. These include heterogeneous mixed lytic and sclerotic lesions involving the ribs.

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Figure 2.

Posterior view of a congenital spindle cell hemangioendothelioma measuring 30 cm × 20 cm involving the left posterior chest wall. Note the additional 2 cm midline vascular nodule.

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Figure 3.

Posterolateral view of a congenital spindle cell hemangioendothelioma involving the left posterior chest wall.

Discussion

Spindle cell hemangioendotheliomas were first described in the literature by Weiss and Enzinger in 1986 in a series of 26 cases. ³ The authors categorized this lesion as a low-grade angiosarcoma, a vascular neoplasm of borderline malignancy. These rare painless masses typically presented in the subcutaneous tissue and increased slowly over several years. Recurrence following excision is common.

In 1991, Fletcher et al published 20 case series and suggested that spindle cell hemangioendotheliomas were more likely to be benign lesions with surrounding arteriovenous shunts. ¹ Each tumour contained dilated vascular spaces with recent or organized thrombi. Fletcher et al proposed that spindle cell hemangioendotheliomas may be a reactive vascular lesion associated with a local abnormality of blood flow that may be congenital or acquired. ¹ Eltorky et al theorized that spindle cell hemangioendotheliomas were reactive processes that remained dormant until local disturbances of blood flow developed. ² Imayama et al used ultrasound analyses to support the hypothesis of a benign mass rather than malignant. ⁴ Perkins and Weiss presented a large case series of 78 spindle cell hemangioendotheliomas and showed that they do not metastasize; however, they recurred commonly following excision. ⁵

The term “spindle cell hemangiomas” is now preferred by some purists as the mass is felt not to have malignant potential. ⁶ Despite the changing position on pathology and prognosis, the presentation of spindle cell hemangioendotheliomas has remained consistent. Typically, a patient will present with a solitary mass or multiple non-tender, subcutaneous, well-defined nodules. ^3,6 Masses present primarily in distal extremities. ^3,6,7 Typically, nodules slowly increase in size or number over the course of years. Pathologically, these nodules are characterized by large, dilated endothelial-lined vascular spaces with thin-walled vessels partially filled with organized thrombi and fascicles of relatively uniform spindle cells. ^1,2,4 Recurrence after excision is very common: higher than 50% to 60% in 1 study. ⁷ The masses may present at any age, with a slight male predominance found in 1 study. ⁴

Conclusion

We present a long-term case report supporting the conservative management of spindle cell hemangioendotheliomas. Spindle cell hemangiomas behave as benign lesions.