Epithelioid hemangioendothelioma is an uncommon vascular tumor of intermediate malignancy that was first described by Steven Billings, Andrew Folpe, and Sharon Weiss in 2003. These tumors are so named because their histologic appearance resembles a proliferation of epithelioid cells, with polygonal shape and eosinophilic cytoplasm.
Composite hemangioendothelioma is a low-grade angiosarcoma typically occurring in adults, although it has been described in infancy.
Spindle-cell hemangioendothelioma) is a vascular tumor that was first described in 1986 by Sharon Weiss, M.D., and commonly presents in a child or young adult who develops blue nodules of firm consistency on a distal extremity. These tumors were reclassified by Dr. Weiss in 1996 as "spindle cell hemangioma", rather than hemangioendothelioma, due to the excellent prognosis observed in a group of 78 patients.
Retiform hemangioendothelioma is a low-grade angiosarcoma, first described in 1994, presenting as a slow-growing exophytic mass, dermalplaque, or subcutaneous nodule.
Kaposiform hemangioendothelioma is an uncommon vascular tumor, first described by Niedt, Greco, et al., "Dabska-type hemangioendothelioma", "hobnail hemangioendothelioma", and "malignant endovascular papillary angioendothelioma", is a rare low-grade angiosarcoma of lymphatic channels. Approximately 30 such tumors have been described in the medical literature. Although included in the World Health Organization tumor classification, there is uncertainty as to whether EPA is a distinct entity or a heterogenous group of tumours. The lesion usually presents as a slow-growing tumor of the skin and subcutaneous tissues of the head, neck, or extremity, of infants or young children. However, EPA has involved the testicle, deep muscle tissue as a neoplastic transformation of a larger existing benigncavernous hemangioma, bone and spleen, and has been found in adults. Some reports indicate a good prognosis but metastasis is occasionally seen.
Infantile hemangioendothelioma is a rare benign vascular tumour arising from mesenchymal tissue and is usually located in the liver. It often presents in infancy with cardiac failure because of extensive arteriovenous shunting within the lesion. It is the third most common liver tumor in children, the most common benign vascular tumor of the liver in infancy, and the most common symptomatic liver tumor during the first 6 months of life. These hemangioendotheliomas have 2 growth phases: an initial rapid growth phase, which is followed by a period of spontaneous involution. Detection of the hemangioendothelioma within the first 6 months of life is attributed to the initial rapid growth during this time; however, the tumor has been detected with fetal ultrasonography. Histopathologically, there are 2 types of hepatic hemangioendotheliomas:
* Type I: Hemagioendotheliomas of this type have multiple vascular channels that are formed by an immature endothelial lining with stromal separation from bile ductules.
* Type II: These hemangioendotheliomas have an appearance that is more disorganized and hypercellular, and there are no bile ductules.
Treatment
Treatment is varied and depends on the site and extent of tumor involvement, site of metastasis, and specific individual factors. Surgical resection, radiotherapy, and chemotherapy have all been used to treat these masses, although studies on survival have yet to be conducted to delineate various treatment regimens.Kaposiform hemangioendothelioma might respond to chemotherapy or antiangiogenic therapies. Recently propanolol and steroids have been shown to be very effective in kaposiform hemangioendothelioma.
