Fig. 3

a Intraoperative photograph. The mass was dissected easily as there was no strong adhesion to the skin, tendon sheath, or neurovascular bundles. b-d Gross and microscopic findings for the resected surgical specimen. b The mass is circumferential and yellowish-white (the mass is divided into two pieces). c Hematoxylin and eosin (H&E) staining of the mass sections (magnification 40×). The mass is well-circumscribed and contains abundant fibrous tissues. d H&E staining of mass section (magnification 200×). The spindle cells contain elongated and cytologically bland nuclei with a fine chromatin pattern (black arrowheads). Nuclear pleomorphism and multinucleated giant cells were not observed