Composite hemangioendothelioma

Last revised by Joachim Feger on 20 Oct 2022

Composite hemangioendotheliomas are locally aggressive and rarely metastasizing vascular tumors consisting of different and histologically distinct elements.

Composite hemangioendotheliomas are very rare and mostly seen in adults. Women are slightly more commonly affected 1,2.

The diagnosis of composite hemangioendothelioma is established histologically 1.

The diagnostic criterion according to the WHO classification of soft tissue and bone tumors (5th edition)1:

  • presence of two or more morphologically distinct tumor components (usually similar to hemangioendothelioma and epithelioid hemangioendothelioma)
  • at least two additional endothelial tumor elements in cases originating from pre-existing vascular or lymphatic malformations
  • conventional angiosarcoma needs to be excluded clinically and morphologically if there are foci resembling high-grade angiosarcoma

The typical complaint is a lump with a reddish-to-purple appearance which has been there for a long time 1.

Composite hemangioendotheliomas are seen in patients with lymphedema 1

Composite hemangioendotheliomas are formed by at least two histologically different vascular tumor components. These parts often resemble retiform or epithelioid hemangioendotheliomas 1.

Chronic lymphedema and irradiation are thought to have a role in the etiology 1.

Neuroendocrine composite hemangioendothelioma is the only subtype.

Composite hemangioendotheliomas most frequently affect the skin and subcutaneous tissues of the distal extremities or the head and neck area but have been also found in other sites 1,2

Macroscopically composite hemangioendotheliomas are nodular infiltrative ill-defined lesions 1,2

The microscopic spectrum of composite hemangioendotheliomas consists of a composition of different morphological vascular components and areas including the following 1,2:

Neuroendocrine composite hemangioendotheliomas are typically composed of epithelioid and retiform hemangioendothelioma-like parts with a nest-like appearance 1.

Immunohistochemistry stains usually express CD31, ERG and FLI1 and can be positive CD34 and D2-40 1.

Fusions of the PTBP1-MAML2 and EPC1-PCH2 genes have been observed in neuroendocrine composite hemangioendotheliomas 1.

Composite hemangioendotheliomas are vascular lesions with a lobulated and heterogeneous appearance 2-4

  • T1: low to intermediate signal intensity
  • T2: high signal intensity
  • T2FS/STIR: high signal
  • T1 C+ (Gd): avid enhancement 

The radiological report should include a description of the following features:

  • form, location and size
  • tumor margins
  • relation to the muscular fascia
  • relationship to bones, tendons and joints
  • relationship to local nerves and vessels

Due to the rarity of the tumors, there is no clear management strategy as yet. Treatment usually consists of surgical excision. Local recurrence is common and can happen multiple times. Lymph node metastases can occur. Distant metastases are seen in neuroendocrine composite hemangioendotheliomas, which are more aggressive 1.

Composite hemangioendotheliomas were first described by an international group around the South African pathologist Simon J. Nayler in 2000 5.

The differential diagnosis of composite hemangioendotheliomas consists of the following:

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