PMC6205313_01
(a) Well circumscribed, 2 cm mass on left anterior tip of the tongue. (b) Tongue after excision of the mass.
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Oral cavity examination revealed a well circumscribed mass on the left anterior tip of the tongue (Figure 1(a)). The mass was removed with 2.0 mm margins around the lesion (Figure 1(b)).
Histology of plexiform schwannoma. (a) Tumor cells forming interlacing fascicles and nodules (plexiform growth) (H&E, X20). (b) Cellular area with Verocay bodies (arrow), formed by palisading of nuclei and separated by cell processes of Schwann cells (H&E, X100). (c) Tumor cells are strongly and diffusely positive for S-100 (X100). (d) EMA-positive perineural fibroblasts surrounding nodules (X40).
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Histopathological examination revealed a spindle cell tumor with multinodular growth pattern, resulting from interlacing fascicles of Schwann cells (plexiform growth) (Figure 2(a)). Most of the tumor consists of cellular areas (Antoni type A) with Verocay bodies, formed by palisading of nuclei and separated by cell processes of Schwann cells (Figure 2(b)). Immunohistochemical analysis revealed the tumor cells to be strongly positive for S-100 protein (Figure 2(c)) and negative for smooth muscle actin (SMA). EMA highlighted perineural fibroblasts surrounding tumor nodules (Figure 2(d)).