Infantile myofibromatosis is a rare benign tumour usually occurring early in infancy. We describe the case of a 10-year-old boy with solitary infantile myofibromatosis in the left lateral orbit floor which regressed spontaneously. Although our patient was older than previously reported cases and showed bony destruction confirmed by computed tomography (CT), this tumour was diagnosed as infantile myofibromatosis based on immunohistochemical findings. The tumour disappeared spontaneously six months after incisional biopsy, that also indicated this tumour was an infantile myofibromatosis.

Myofibromatosis is an uncommon, usually cutaneous, condition in which there is a benign proliferation of myofibroblasts. Solitary and multicentric nodular forms with, and without, visceral involvement have been described. Infantile and adult sub-types have been reported, each having distinct clinicopathological features. Presentation in the head and neck is common. It is frequently misdiagnosed because of its peculiar histological features. The first documented cases of infantile and adult myofibromatosis involving the nasal cavity are reported.