Extramedullary hematopoiesis within endothelial papillary hyperplasia (Masson？s pseudoangiosarcoma) of the tongue

we report the unique association of masson？s pseudoangiosarcoma (endothelial papillary hyperplasia) and extramedullary hematopoiesis. the lesion was present as a violaceous nodule on the side of the tongue of a 78-year-old man with history of multiple myeloma and long-standing mild anemia. this association between a peculiar form of thrombus organization and extramedullary hematopoiesis has been reported previously only once, in an infant with a cranial hematoma, and raises interesting pathogenetic questions.