Sublingual solitary fibrous tumour: a rare clinical encounter.

A woman in her 30s presented at the otolaryngology outpatient department with a chief complaint of a gradually enlarging soft swelling in the left side of the floor of her mouth persisting for 9 months. Clinical examination revealed a 3×3 cm smooth, firm, non-tender, pinkish mass on the left floor of the mouth, extending towards the frenulum, causing upward and rightward displacement of the tongue. Radiological studies suggested an aggressive vascular neoplastic lesion, prompting a decision for surgical excision postembolisation. Histopathological analysis indicated a haemangioendothelioma, whereas immunohistochemistry confirmed the diagnosis of a solitary fibrous tumour. Therefore, a comprehensive analysis of the biopsy specimen is crucial for the precise diagnosis of such rare tumours.