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Int J Clin Exp Pathol 2013;6(10):2230-2236

Case Report
Desmoplastic fibroma of the scapula with fluorodeoxyglucose uptake on positron
emission tomography: a case report and literature review

Taketo Okubo, Tsuyoshi Saito, Tatsuya Takagi, Tomoaki Torigoe, Yoshiyuki Suehara, Keisuke Akaike, Takashi Yao, Kazuo Kaneko
Department of Orthopaedic Surgery, Juntendo University School of Medicine, Japan; Department of Human Pathology, Juntendo University
School of Medicine, Japan

Received August 6, 2013; Accepted August 22, 2013; Epub September 15, 2013; Published October 1, 2013

Abstract: We present a case of desmoplastic fibroma (DF) arising from the right scapula that was incidentally identified by fluorodeoxyglucose-
positron emission tomography (FDG-PET) imaging performed to evaluate the presence of metastasis due to a history of surgical treatment for
endometrioid adenocarcinoma. A 65-year-old woman was admitted to our hospital for consultation about a bone lesion in the right scapula
although she was asymptomatic. FDG-PET revealed moderate focal 18F-FDG uptake in the right scapula with a maximal standardized uptake
value of 3.2. The lower angle of the scapula was unclear on plain radiology. Needle biopsy was performed to make a differential diagnosis
between primary bone and metastatic tumor. Pathologically, the tumor was composed of a relatively sparse proliferation of spindle-shaped
fibroblastic/myofibroblastic cells in a dense collagenous background. Therefore, the diagnosis was a primary fibrous bone tumor. Wide
excision was performed, because of the possibility of malignant tumors such as low-grade fibrosarcoma in light of the FDG-PET uptake.
Pathologically, the resected tumor was composed of a proliferation of less atypical spindle cells in the collagenous stroma with focally myxoid
change; no mitotic figures were observed. Immunohistochemically, β-catenin nuclear/cytoplasmic staining was not observed, and no β-catenin
genetic mutations were detected. Therefore, the tumor was diagnosed as DF. DF is a tumor that exhibits FDG-PET uptake. There were no
signs of recurrence 6 months after surgery. (IJCEP1308014).

Keywords: Desmoplastic fibroma, scapula, β-catenin, positron emission tomography (PET)

Address correspondence to: Dr. Tsuyoshi Saito, Department of Human Pathology, Juntendo University School of Medicine, Hongo 2-1-1,
Bunkyo-Ku, Tokyo, Japan 113-8421. Tel: +81-3-3813-3111; Fax: +81-3-3813-3428; E-mail: tysaitou@juntendo.ac.jp