ALT A 42-year-old male with neurofibromatosis type 1 presents with a rapidly enlarging, painful mass in his deep gluteal region. High power view demonstrating the spindle shaped and wavy nuclei characteristic of this tumor @IARCWHO

ALT A tissue fragment composed of uniform spindle cells with nuclear palisading and areas without nuclei, creating Verocay bodies (in particular centrally) (H&E). @IARCWHO

ALT Tissue fragments showing intertwining spindle cells in a net-like pattern with fibrillary stroma (Giemsa).

ALT A tissue fragment with spindle cells with elongate, sometimes wavy nuclei in a fibrillary stroma. Nuclear inclusions are a common finding (H&E). @IARCWHO

ALT A hypocellular tissue fragment with delicate fibrillary stroma and focal elongated nuclei (Giemsa). @IARCWHO

ALT Cells show vacuolated cytoplasm and central uniform nuclei