Aberrant VEGF Expression Associated With Neoplasm-Induced Extramedullary Hematopoiesis in an Epithelioid Hemangioendothelioma

Abstract

The authors present the first report of extramedullary hematopoiesis occurring in association with an epithelioid hemangioendothelioma. A 64-year-old man sought medical attention for upper chest pain. CT evaluation identified a 2.8-cm mass involving the right hemithorax in the area of the right upper lobe and superior vena cava. A biopsy revealed the presence of an epithelioid malignant vascular neoplasm, which on subsequent resection was found to be an epithelioid hemangioendothelioma. The neoplasm was closely associated with an area of extramedullary hematopoiesis. VEGF immunohistochemical staining of the neoplasm revealed a ring of intensely positive staining cells around the periphery of the area of extramedullary hematopoiesis. This finding provides evidence for the role of aberrant VEGF expression in neoplasm-induced extramedullary hematopoiesis. This report discusses possible mechanisms by which extramedullary hematopoiesis may occur in vascular neoplasms.