Large retroperitoneal atypical spindle cell lipomatous tumor, an extremely rare neoplasm: A case report

Figure 2 Microscopic findings. A: The neoplasm shows spindle cells with mild nuclear atypia and hyperchromatia. There are admixed adipocytes (Hematoxylin and eosin stain, × 100); B: The variation of adipocytic size and myxoid stroma are present (Hematoxylin and eosin stain, × 100); C: The spindle cells are negative for MDM2 (Immunohistochemical stain, × 200); D: Fluorescence in situ hybridization shows no MDM2 amplification.