case_images: PMC10871025_01
case_images: Lateral radiograph of right ankle demonstrating soft tissue mass with calcifications (arrow).
case_images: cureus-0016-00000052438-i01.jpg
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case_images: FIG1
case_images: Coronal MRI (proton density-weighted, fat-suppressed, turbo spin echo) demonstrating the structure of the lesion along the lateral aspect of the right knee.. MRI, magnetic resonance imaging
case_images: cureus-0016-00000052438-i02.jpg
case_images: PMC10871025_01_cureus-0016-00000052438-i02.jpg
case_images: FIG2
case_images: The lesion exhibited a predominantly bright T2 signal, as depicted in the right knee coronal MRI (Figure 2).
case_images: Axial MRI of the right knee (T1-weighted, post-contrast) demonstrating peripheral contrast enhancement along the laterally located lesion (arrow).. MRI, magnetic resonance imaging
case_images: cureus-0016-00000052438-i03.jpg
case_images: PMC10871025_01_cureus-0016-00000052438-i03.jpg
case_images: FIG3
case_images: Peripheral enhancement was noted with gadolinium-based contrast, as depicted in the contrast-enhanced axial right knee MRI (Figure 3).
case_images: Hematoxylin and eosin-stained specimen at low magnification (4x), illustrating nodular collections of spindle-like myofibroblasts.
case_images: cureus-0016-00000052438-i04.jpg
case_images: PMC10871025_01_cureus-0016-00000052438-i04.jpg
case_images: FIG4
case_images: The microscopic appearance revealed nodular proliferations of eosinophilic, fusiform myofibroblasts surrounded by less differentiated pericytes, as shown in the histopathologic microphotograph (Figure 4).