Infantile fibromatosis of the submandibular region

Abstract

Infantile fibromatosis is a fibromatous lesion that arises in both soft and hard tissues, and occurs rarely in the head and neck region. A three-year-old boy was referred to our clinic because of painful swelling of the left submandibular region. CT scans and MRI revealed a localized perimandibular soft tissue mass, which suggested a malignant tumor, but we could not make a definitive pathological diagnosis from the needle biopsy specimens. The tumor was removed surgically while taking into consideration to avoid disturbing the maxillofacial cosmesis and functions. The pathological findings of the surgical specimen showed a tumor composed of spindle cells with no cellular atypia and mitosis, but showed invasion into the surrounding muscular tissue, and the final pathological diagnosis was infantile fibromatosis. There is no evidence of recurrence for five years postoperatively, but we have to close follow-up carefully because recurrence of the tumor after surgical resection was reported.