Epithelioid hemangioendothelioma a vascular tumor often mistaken for a carcinoma

Abstract

Epithelioid hemangioendothelioma is a unique tumor of adult life which is characterized by an “epithelioid” or “histiocytoid” endothelial cell. Forty‐one cases of this rare tumor have been recognized at the Armed Forces Institute of Pathology. They may occur in either superficial or deep soft tissue, and in 26 cases appeared to arise from a vessel, usually a medium‐sized or large vein. They are composed of rounded or slightly spindled eosinophilic endothelial cells with rounded nuclei and prominent cytoplasmic vacuolization. The latter feature probably represents primitive lumen formation by a single cell. The cells grow in small nests or cords and only focally line well‐formed vascular channels. The pattern of solid growth and the epithelioid appearance of the endothelium frequently leads to the mistaken diagnosis of metastatic carcinoma. The tumor can be distinguished from a carcinoma by the lack of pleomorphism and mitotic activity in most instances and by the presence of focal vascular channels. Ultrastructural study in four cases confirmed the endothelial nature of the tumor in demonstrating cells surrounded by basal lamina, dotted with surface pinocytotic vesicles, and occassionally containing Weibel‐Palade bodies. Follow‐up information in 31 cases indicated that 20 patients were alive and well following therapy; three developed local recurrences and six metastases. It is suggested the term epithelioid hemangioendothelioma be used to designate these biologically “borderline” neoplasms. The significance of the epithelioid endothelial cell is not entirely clear. Since it may be observed in both benign and malignant vascular lesions, its presence alone does not define a clinicopathologic entity.

Superficial CD34-positive fibroblastic tumor: report of 18 cases of a distinctive low-grade mesenchymal neoplasm of intermediate (borderline) malignancy

“…33,34 Furthermore, the lesions that we have described show retained expression of SMARCB1, unlike the great majority of epithelioid sarcomas. 35 Similarly, the morphological features of superficial CD34-positive fibroblastic sarcoma are quite dissimilar from those of epithelioid angiosarcoma, 36 epithelioid hemangioendothelioma, 37 and epithelioid sarcoma-like hemangioendothelioma, 38,39 and these tumors lack expression of the endothelial markers FLI-1 and ERG. 40-42 Figure 6 All tumors strongly expressed CD34 (a), and most of them were also positive for cytokeratins (b).…”

Podoplanin is a useful diagnostic marker for epithelioid hemangioendothelioma of the liver

“…The term epithelioid hemangioendothelioma was established by Drs Weiss and Enzinger to describe a soft-tissue tumor of endothelial origin with a clinical course in between that of benign hemangioma and that of angiosarcoma. 11 Primary hepatic epithelioid hemangioendothelioma, first reported by Ishak et al, 12 shows low-grade malignant potential and has a better clinical outcome than angiosarcoma. 13 It is important to distinguish epithelioid hemangioendothelioma from carcinoma or angiosarcoma, because patients with epithelioid hemangioendothelioma can survive for a long term.…”

Malignant vascular tumors—an update

“…However, 20-30% of tumors metastasize, and about 15% of patients die of their disease. 4,15 This contrasts with the behavior of most angiosarcomas. Overtly malignant lesions typically pursue an aggressive course.…”

“…3 EHE of soft tissue was first described by Weiss and Enzinger. 4 As its clinical behavior is intermediate between a benign hemangioma and a high-grade angiosarcoma, the term 'hemangioendothelioma' was suggested. Subsequently, EHE of soft tissue was stratified into two risk groups of malignancy, classic and malignant EHE, based on mitotic activity and size, in an effort to reflect different biological subsets.…”