Fig. 4

Case 4. (a and b) MRI before first surgery shows a circular-like isointense lesion with a size of 1.4 cm × 1.5 cm located in the superior temporal area of the muscle cone behind the eyeball, compressing the optic nerve in the axial scan of the orbit on T1- and T2-weighted images. (c) MRI before first surgery shows nonhomogeneous enhancement of the lesion in the axial and coronal scan of the T2-weighted image. (d) MRI before first surgery shows a circular-like lesion located in the superior temporal area of the muscle cone behind the eyeball in the sagittal scan of the T1-weighted image. (e and f) CDU before first and second surgeries show the irregular isoechoic to hyperechoic mass with well-defined border behind the eyeball, and the optic nerve is compressed to displace to the nasal temporal area at the time of the relapse. (g and h) Histopathology show a large percentage of undifferentiated mesenchymal cells, which were elliptical or short shuttle in first specimen, and stratified distribution in the recurrent specimen (×20), yellow\(\:\to\:\), undifferentiated mesenchymal round cells; yellow\(\:\to\:\), areas of immature cartilage; (i) CT image of 8 months after the second surgery, axial scan of the orbit on soft tissue window, and slight thickening of soft tissue in the temporal aspect of the left orbit