Fig. 4

Histological findings of the tumor. a On sectioning, a well-demarcated nodular tumor, measuring 3.2 × 2.3 × 2.0 cm, was observed. The tumor was a solid, firm, gray-white mass, without necrotic foci or hemorrhage. b Magnification × 10. c Magnification × 100. d Magnification × 400. Histologically, the tumor was composed of spindle cells arranged in fascicles or storiform growth pattern in fibrous stroma. Neoplastic cells have ill-defined cytoplasm and nuclei with atypia. A few mitoses were observed, and there was not hypercellular area or necrosis