Oral Schwannoma — MFDS Part 1 MCQ

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ModerateOral PathologyOral SchwannomaMFDS Part 1

A 32-year-old patient has a painless, slowly enlarging, well-circumscribed nodule on the lateral tongue. Histological examination shows an encapsulated spindle-cell tumour with alternating hypercellular and hypocellular areas, Verocay bodies and diffuse S100 positivity. From which cell type does this lesion arise?

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Correct answer: A — Schwann cells

Explanation lettering: D = shown as B · B = shown as C · E = shown as D · C = shown as E

The lesion is a schwannoma, a benign peripheral nerve-sheath tumour arising from Schwann cells. Its discriminating features are encapsulation, hypercellular Antoni A and hypocellular Antoni B areas, Verocay bodies formed by nuclear palisading, and diffuse S100 expression. Perineurial cells instead give rise to perineurioma. Endoneurial fibroblasts may contribute to the mixed cellular composition of neurofibroma but are not the origin of schwannoma. Melanocytes can also express S100, but a melanoma would not show the characteristic encapsulated Antoni A/B architecture and Verocay bodies. Squamous epithelial cells give rise to epithelial lesions such as squamous cell carcinoma rather than peripheral nerve-sheath tumours.

Reference: Pathological Diversity in Schwannomas of the Orofacial Region, 2021. https://pubmed.ncbi.nlm.nih.gov/34268175/