case_images: PMC6381854_01
case_images: Sagittal view of the right knee magnetic resonance imaging; T2 view showing high-signal intensity in the anterior cruciate ligaments, Baker's cyst and absence of pigmented villonodular synovitis features (a and b)
case_images: SJMMS-7-44-g001.jpg
case_images: PMC6381854_01_SJMMS-7-44-g001.jpg
case_images: F1
case_images: Furthermore, a small Baker's cyst was noted [Figure 1].
case_images: (a and b) Cellular proliferation of mononucleated synoviocyte, macrophages and multinucleated giant cells (H and E); (c and d) Multinucleated giant cells and brown hemosiderin pigments (H and E)
case_images: SJMMS-7-44-g002.jpg
case_images: PMC6381854_01_SJMMS-7-44-g002.jpg
case_images: F2
case_images: Microscopically, a circumscribed lesion consisting of sheets of mononuclear synoviocytes mixed with multinucleated giant cells and foamy histiocytes along with focal hemosiderin pigmentation was noted [Figure 2].