Schwannoma : Antoni A Areas
Schwannomas are composed of cellular Antoni A areas alternating with hypocellular Antoni B areas. Antoni A areas are composed of interlacing bundles of spindle cells (Schwann cells) with wavy or oval nuclei, eosinophilic cytoplasm, and indistinct cytoplasmic borders (as shown here). Intranuclear vacuoles may be present. Frequently, the Schwann cells in Antoni A areas show nuclear palisading, whorling patterns, and Verocay bodies that formed by a highly ordered arrangement of Schwann cell nuclei in parallel rows separated by fibrillary processes. Occasional mitotic figures may be present.