FDG-PET/CT and CT findings of a benign solitary fibrous tumor of the kidney: correlation with pathology

Document Type : Case report


1 Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women’s Medical University, Tokyo, Japan

2 Department of Urology, Tokyo Women’s Medical University, Tokyo, Japan

3 Department of Surgical Pathology, Tokyo Women’s Medical University, Tokyo, Japan


Herein, we report the F-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) findings of a benign solitary fibrous tumor (SFT) of the kidney. The patient was a 63-year-old woman with a mass in the right kidney (10×9.7 cm), incidentally found on CT images. The CT scan showed a lobulated tumor arising from the hilum of the right kidney. The tumor consisted of two components with different patterns of enhancement. Most of the tumor demonstrated moderate enhancement from the corticomedullary to nephrographic phase. A small nodular component at the caudal portion of the tumor showed avid enhancement in the corticomedullary phase and rapid washout in the nephrographic phase in contrast-enhanced CT. FDG-PET/CT was performed and showed weak FDG accumulation (SUVmax=2.30 and 1.91 in the main and small caudal components). Although renal cell carcinoma was preoperatively diagnosed, histopathological examination revealed renal SFT, with no malignant potential. Therefore, when a renal tumor with contrast-medium enhancement and low FDG accumulation is demonstrated, SFT should be considered as a differential diagnosis in addition to renal cell carcinoma.


Main Subjects


    1. Gold JS, Antonescu CR, Hajdu C, Ferrone CR, Hussain M, Lewis JJ, et al. Clinicopathologic correlates of solitary fibrous tumors. Cancer. 2002;94(4):1057- 68.
    2. Znati K, Chbani L, El Fatemi H, Harmouch T, Kamaoui I, Tazi F, et al. Solitary fibrous tumor of the kidney: a case report and review of the literature. Rev Urol. 2007;9(1):36-40.
    3. Mearini E, Cochetti G, Barillaro F, Fatigoni S, Roila F. Renal malignant solitary fibrous tumor with single lymph node involvement: report of unusual metastasis and review of the literature. Onco Targets Ther. 2014;7:679-85.
    4. Khater N, Khauli R, Shahait M, Degheili J, Khalifeh I, Aoun J. Solitary fibrous tumors of the kidneys: presentation, evaluation, and treatment. Urol Int. 2013;91(4):373-83.
    5. Katabathina VS, Vikram R, Nagar AM, Tamboli P, Menias CO, Prasad SR. Mesenchymal neoplasms of the kidney in adults: imaging spectrum with radiologic-pathologic correlation. Radiographics. 2010;30(6):1525-40.
    6. Kuroda N, Ohe C, Sakaida N, Uemura Y, Inoue K, Nagashima Y, et al. Solitary fibrous tumor of the kidney with focus on clinical and pathobiological aspects. Int J Clin Exp Pathol. 2014;7(6):2737-42.
    7. Gengler C, Guillou L. Solitary fibrous tumour and haemangiopericytoma: evolution of a concept. Histopathology. 2006;48(1):63-74.
    8. Cheah AL, Billings SD, Goldblum JR, Carver P, Tanas MZ, Rubin BP. STAT6 rabbit monoclonal antibody is a robust diagnostic tool for the distinction of solitary fibrous tumour from its mimics. Pathology. 2014;46(5):389-95.
    9. Bertagna F, Motta F, Bertoli M, Bosio G, Fisogni S, Tardanico R, et al. Role of F18-FDG-PET/CT in restaging patients affected by renal carcinoma. Nucl Med Rev Cent East Eur. 2013;16(1):3-8.
    10. Yan J, Mann F, Lewis D, Eary JF. Solitary fibrous tumor: WHO classification, histopathological correlation contribution to the Radiology-Pathology Conference, FDG PET-CT imaging, and biological behaviors. Clin Imaging. 2013;37(5):977-8.
    11. Song L, Zhang W, Zhang Y. 18F-FDG PET/CT Imaging of Malignant Hepatic Solitary Fibrous Tumor. Clin Nucl Med. 2014;39(7):662-4.
    12. Lococo F, Cafarotti S, Treglia G. Is 18F-FDG-PET/CT really able to differentiate between malignant and benign solitary fibrous tumor of the pleura? Clin Imaging. 2013;37(5):976-7.
    13. Treglia G, Oragano L, Fadda G, Raffaelli M, Lombardi CP, Castaldi P, et al. A rare case of solitary fibrous tumor of the adrenal gland detected by (18)F-FDG PET/CT. Clin Nucl Med. 2014;39(5):475-7.
    14. Dong A, Zuo C, Wang Y, Cui Y. Enhanced CT and FDG PET/CT in malignant solitary fibrous tumor of the lung. Clin Nucl Med. 2014;39(5):488-91.