2) The Antoni A region is a hypercellular zone whose cells are fusiform with nuclei arranged in palisade forming parallel rows and producing the Verocay bodies
Histopathologically gastrointestinal schwannoma are spindle shaped cells with a prominent lymphocytic cuff and are characterized by the absence of typical Verocay bodies
, Antoni A and Antoni B areas10.
Scattered prominent Verocay bodies
were also identified (Fig 5).
Palisaded nuclei and acellular reticular fibres in between these nuclei form Verocay bodies
but are ill defined usually.
Caption: Figure 4: Histological images: (a) intense nuclear atypia (hematoxylin and eosin stain, x100), (b) Verocay bodies
(hematoxylin and eosin stain, x100), (c) immunohistochemical reaction for S-100, and (d) immunohistochemical reaction for vimentin.
Antoni A areas were composed of spindle-shaped cells forming Verocay bodies
Unlike conventional schwannomas, they are uncircumscribed, infiltrate around and between individual crypts, and lack cellular atypia, a lymphoid cuff, and prominent Verocay bodies
(11, 12) (Figure 1, C).
The first Antoni A pattern showed closely arranged bundles of schwann cells with spindle-shaped nuclei which were aligned in parallel rows, which formed a typical palisading pattern around acellular, amorphous, eosinophilic masses, which represented the verocay bodies
The histopathological report showed an arrangement of spindle cells in a storiform pattern with Verocay bodies
interspersed with myxomatous areas.
Schwannomas are peripheral nerve sheath tumors that, in contrast to neuromas, have thick collagenous capsules, true Verocay bodies
, and hypocellular or myxoid (Antoni B) stroma (3).
Microscopic findings showed fascicles of spindle shaped cells with Verocay bodies
consistent with a diagnosis of a schwannoma.
Those elements are Antoni A tissue, composed of closely packed spindle shaped cells arranged in a palisading network; Antoni B tissue that is far less organized, consisting of myxoid tissue with cystic spaces and sparsely populated with cells; and Verocay bodies
that are linear arrays of spindle cell nuclei.