case_images: PMC6920296_01
case_images: Lump at the posterior knee joint with limited range of motion.
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case_images: PMC6920296_01_gr1.jpg
case_images: fig0005
case_images: A physical examination revealed a mass (sized 10 x 9 x 7 cm) with limited range of motion (ROM) extension 30 , flexion 70  (Fig. 1).
case_images: MRI revealed soft tissue mass sized 10 x 9 x 7 cm at posterior compartment of knee (white arrow).
case_images: gr2.jpg
case_images: PMC6920296_01_gr2.jpg
case_images: fig0010
case_images: Magnetic resonance imaging (MRI) revealed a soft tissue mass at the posterior compartment of the knee (Fig. 2).
case_images: Histological examination showed a circumscribed and lobulated hypo cellular mass containing spindle cells.
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case_images: PMC6920296_01_gr3.jpg
case_images: fig0015
case_images: Histologic study was taken from core biopsy examination and the result showed a circumscribed and lobulated hypo cellular mass containing spindle cells (Fig. 3).
case_images: The ellips incision was made around the biopsy site.
case_images: gr4.jpg
case_images: PMC6920296_01_gr4.jpg
case_images: fig0020
case_images: The ellipse incision was made 2 cm margin of skin around the biopsy site (Fig. 4).
case_images: Tumor mass was embbeded in the posterior compartment of the knee.
case_images: gr5.jpg
case_images: PMC6920296_01_gr5.jpg
case_images: fig0025
case_images: Tumor mass had a partial well-defined capsule, popliteal artery and vein was embedded, and pressing the sciatic nerve (Fig. 5).
case_images: The popliteal artery was reconstructed with saphenous vein graft.
case_images: gr6.jpg
case_images: PMC6920296_01_gr6.jpg
case_images: fig0030
case_images: The popliteal artery was reconstructed with saphenous veins graft (Fig. 6).