Question: A 48-year-old female with several months of paresthesias to the left posterior ankle and hindfoot that worsened with ambulation [Figs. 1, 2, 3, and 4].

Fig. 1
figure 1

Lateral radiograph

Fig. 2
figure 2

Left ankle MRI with axial (a-c) and sagittal (d-f) images. (a) T1-weighted, (b) Fat-saturated T2-weighted, (c) Fat-saturated T1-weighted pre-contrast, (d) T1-weighted, (e) Fat-saturated T2- weighted, (f) Fat-saturated T1-weighted post-contrast

Fig. 3
figure 3

Gross surgical specimen

Fig. 4
figure 4

Histology (H&E, 40X)