Histopathological findings from the peripheral nerve sheath malignant tumor in the heart of a cow. (A) Dense fusiform cell proliferation arranged in short bundles in several directions and forming irregular nests bordered by fibrovascular stroma (type A Antoni pattern). Bar = 90 μm, H&E. (B) Proliferation of loose, round-to-oval-shaped neoplastic cells with indistinct edges and surrounded by a mildly basophilic myxoid matrix (type B Antoni pattern). Bar = 100 μm, H&E. (C) Neoplastic cells with an epithelioid appearance. Bar = 70 μm, H&E. (D) Proliferation focus of granular cells. Bar = 50 μm, H&E.