Figure 3
Surgical, pathological, and immunohistochemistry findings. After incision of the lateral capsule of the elbow, the encapsulated mass (yellow arrow) was exposed and excised (a). Pathological examination revealed typical histological features of nodular fasciitis, comprising cytologically bland, uniform plump spindle cells arranged in short intersecting bundles within a collagenous stroma (b). Immunohistochemistry shows diffuse positivity for smooth muscle actin (c).