A 47-year-old female with idiopathic myelofibrosis developed isolated granulocytic sarcoma with der (1; 7)(q10; p10) after splenectomy, followed by acute myelogenous leukemia. The patient had myelofibrosis since 22 years of age, received splenectomy at 47 years, and developed isolated submandibular granulocytic sarcoma, 8 months later. Although the initial tumor disappeared after irradiation, recurrent tumors selectively appeared in the areas of operative scars. She subsequently developed blastic transformation with der (1; 7)(q10; p10), and the blasts were refractory to different chemotherapy. This case is very rare in the following aspects: the onset of myelofibrosis occurred at a relatively young age; isolated granulocytic sarcoma after splenectomy preceded the transformation to acute leukemia; and the subcutaneous tumors developed in areas of operative scars.