title: Intraosseous leiomyoma of the distal femur: a case report and review of literatures.
abstract: BACKGROUND
  Leiomyoma is a benign tumor of smooth-muscle origin. They most commonly derived from the uterus. Besides, they were also usually diagnosed in the gastrointestinal tract, skin, and mucous membranes. However, it rarely occurs in the bone.
  
  
  METHODS
  The authors reported one case of 56-year-old male with intraosseous leiomyoma of the distal femur. Initially, the patient felt left knee pain for 1 year. Radiographs film disclosed an ill-defined osteolytic lesion with thinning cortex over left distal femoral medial condylar region. Computed tomography (CT) revealed homogenous radiolucent lesion with thinning cortex over the metaphysis of distal femur. Magnetic resonance imaging showed focal marrow replacement by tumor. CT-guide biopsy was performed, and the pathology showed a picture of leiomyoma. Since the definite diagnosis, the lesion was treated with en-bloc resection and endoprosthetic knee joint reconstruction. Satisfied result and disease free were achieved during follow-up.
  
  
  CONCLUSIONS
  Intraosseous leiomyoma of the extremities is difficult to be diagnosed due to extraordinarily rare. This rare benign tumor should be included in the differential diagnosis of any relatively intraosseous lesion with benign imaging findings. This is the first published case of primary intraosseous leiomyoma of distal femur after literature reviews.
authors.affiliation: Department of Orthopedics, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, Kaohsiung City, Taiwan. yhsung@vghks.gov.tw.
authors.forename: Yu-Hsiang
authors.initials: YH
authors.lastname: Sung
authors.affiliation: Department of Orthopedics, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, Kaohsiung City, Taiwan. yangshanwei@yahoo.com.tw.|Department of Biomedical Engineering, I-Shou University, Kaohsiung County, Taiwan. yangshanwei@yahoo.com.tw.|Department of Electrical Engineering, I-Shou University, Kaohsiung County, Taiwan. yangshanwei@yahoo.com.tw.
authors.forename: Shan-Wei
authors.initials: SW
authors.lastname: Yang
authors.affiliation: Department of Orthopedics, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, Kaohsiung City, Taiwan. ywtarng@vghks.gov.tw.
authors.forename: Yih-Wen
authors.initials: YW
authors.lastname: Tarng
authors.affiliation: Department of Biomedical Engineering, I-Shou University, Kaohsiung County, Taiwan. sjchang@isu.edu.tw.
authors.forename: Shwu-Jen
authors.initials: SJ
authors.lastname: Chang
authors.affiliation: Department of Orthopedics, Kaohsiung Veterans General Hospital, 386 Ta-Chung 1st Road, Kaohsiung City, Taiwan. cjhsu@vghks.gov.tw.
authors.forename: Chien-Jen
authors.initials: CJ
authors.lastname: Hsu
authors.affiliation: Department of Electrical Engineering, I-Shou University, Kaohsiung County, Taiwan. lchwang@isu.edu.tw.
authors.forename: Lain-Chyr
authors.initials: LC
authors.lastname: Hwang
keywords: Distal femur; Intraosseous leiomyoma; Wide excision