Submandibular juvenile fibromatosis.

This brief clinical study presents a case of a 2-year-old girl with a submandibular mass that caused erosion of the inferior border of the mandible. An incisional biopsy finding revealed juvenile fibromatosis, that is, a group of fibrous proliferations that have biologic behavior and histopathologic pattern intermediate between those of benign fibrous lesions and fibrosarcoma. These lesions should be treated through wide surgical excision, and patients should be kept under regular follow-up because of their high recurrence rate.