A rare intersection: Oral carcinoma cuniculatum in the context of Down syndrome

Oral carcinoma cuniculatum (OCC) is a rare, well-differentiated variant of oral squamous cell carcinoma, characterized by keratin-filled crypts and a burrowing growth pattern. Its occurrence in individuals with Down syndrome (DS) is exceptionally uncommon due to their reportedly lower risk of solid tumours. We present a rare case of OCC in a 38-year-old woman with DS, who reported a painful lesion on the lateral tongue. Histopathological analysis confirmed OCC, aided by E-cadherin immunohistochemistry to differentiate it from verrucous carcinoma. Surgical excision with neck dissection was performed. The case highlights diagnostic challenges in DS individuals, including misattribution of symptoms and oral hygiene difficulties. This report underscores the importance of awareness camps and early detection of oral malignancies in patients with DS and advocates for targeted education and preventive programmes for caregivers and dental professionals.