MULTIPLE DIFFUSE FIBROSARCOMA OF BONE ASSOCIATED WITH EXTRAMEDULLARY HEMATOPOIESIS

We report a case of multiple diffuse fibrosarcoma of bone. The patient , a 38-year-old man, was referred to our hospital with knee pain, anem ia and thrombocytopenia. No solid mass was seen on radiographic examin ation of the knee joint, but magnetic resonance imaging showed hypoint ensity of the distal femur, Femoral biopsy revealed proliferation of l ong spindle-shaped fibrosarcoma cells, while a bone marrow biopsy of i liac bone (which appeared normal on radiographic examinations) showed replacement of hematopoietic cells by fibroblast-like spindle cells, A diagnosis of multiple diffuse fibrosarcoma of bone was therefore made . Autopsy revealed tumor invasion into multiple bones and several visc eral organs and extramedullary hematopoiesis in the liver, spleen and lymph nodes, As this patient had leukoerythroblastic anemia with poiki locytosis, splenomegaly exhibiting extramedullary hematopoiesis, and a pparent fibrotic change in his bone marrow, we suggest that this extre mely rare disease should be considered in the differential diagnosis o f myelofibrosis.