Intestinal obstruction caused by extramedullary hematopoiesis and ascites in primary myelofibrosis

Figure 4 Extramedullary hematopoietic mass of the small intestine with ulcer and excessive vascular proliferation was confirmed by histopathology. A: A significant quantity of Megakaryocytes along with the accumulation of immature myeloid cells and erythroid cells were observed; B: Megakaryocytes were CD61 positive and CD68 negative (not shown); C: Significant hyperplasia of blood vessels and a large number of infiltrated inflammatory cells were seen; D: Blood vessels were confirmed by positive CD31 staining.