Gingival myofibroma in children: report of 4 cases with immunohistochemical findings.

Oral myofibroma is a rare tumour which usually occurs in children and has been reported in the mandible, tongue, buccal mucosa with only a few cases reported from the gingiva. It appears alarming clinically due to its fast growth which may mimic a malignancy. However, it is completely benign and is usually treated by complete surgical excision with excellent prognosis. Clinically, myofibroma presents as a single swelling when it occurs on the gingiva, and more common lesions such as fibrous epulis, pyogenic granuloma and peripheral odontogenic fibroma, myofibroma are usually considered in the differential diagnosis. We present 4 additional cases of gingival myofibroma in children. Their ages ranged from 7 to 14 years. Three were girls and 1 patient was a boy. All presented with solitary gingival growths, ranging from 3 weeks to 2 months in duration, and raised the clinical diagnoses of peripheral giant cell granuloma, pyogenic granuloma and fibrous epulis. Histopathology of incisional biopsies revealed proliferation of streaming and whorled fascicles of spindle cells around slit-like vascular spaces. The spindle cells were cytologically bland and were immunopositive for vimentin and smooth muscle actin, but were negative for desmin and S-100 protein. All were treated by surgical excision.