PMC8455224_01
(a) T2 fat-suppressed (FS) (TR/TE: 5070/76) midsagittal view of the left knee. TGCT nodules can be seen in the patellofemoral location and superior to the posterior cruciate ligament. (b) T2 FS (TR/TE: 5070/76) parasagittal view showing TGCT  nodules anterior to the intercondylar notch and posterior-superior to the lateral femoral condyle. (c). T2 FS (TR/TE: 4740/76) coronal view showing the same nodules seen in the patellofemoral region of image (a) and the anterior joint region in image (b). The diffuse low signal of the tumors due to hemosiderin deposition is noted.
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fig1
At that time, magnetic resonance imaging (MRI) was performed of his left knee and revealed several multilobulated masses, which can be seen in Figure 1.
Arthroscopic images showing (a) synovitis that was not believed to have TGCT tissue, (b) infarcted TGCT tissue, and (c) viable TGCT tissue.
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fig2
Arthroscopic images are shown in Figure 2, and microscopic images of the tumor biopsies are shown in Figure 3.
Microscopic images of hematoxylin-eosin-stained sections of tumor tissue. Viable TGCT: (a) 100x image illustrating viable TGCT with scattered giant cells (arrows) and (b) 200x image showing a multinucleated giant cell. Infarcted tissue with scattered giant cells (arrows): (c) 100x image of completely infarcted tissue with multinucleated giant cells and (d) 200x image of partially infarcted tissue with a multinucleated giant cell.
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fig3
Arthroscopic images are shown in Figure 2, and microscopic images of the tumor biopsies are shown in Figure 3.