Floor of mouth lesions in the paediatric population are uncommon. The spectrum of pathology that afflicts the floor of mouth spans inflammatory conditions, developmental anomalies, vascular malformations and benign tumours or malignancies. We report a rare case of Gardner-associated fibroma (GAF) presenting as a slow-growing floor of mouth mass in a 10-year-old boy. GAF is associated with Gardner’s syndrome (GS) and familial adenomatous polyposis (FAP), both of which are associated with multiple colonic polyps and increased risk of colorectal malignancy. To our knowledge, this case report represents the first case in the literature of a GAF presenting in the floor of mouth of a paediatric patient, and discusses the clinical implications of this rare diagnosis.

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