Solitary infantile myofibromatosis in the lateral orbit floor showing spontaneous regression.

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.