ABSTRACT
Purpose To investigate the clinicopathological features of the adult rhabdomyoma (A-RM) in the oral and maxillofacial region.Methods Three cases of A-RM in the oral and maxillofacial region were analyzed for the clinical symptoms,imaging data,pathological features,differential diagnosis,treatment,and prognosis with the literatures review.Results The age arranged from 4 yea~ to 83 years in three A-RM cases.Two cases were male and one case was female.Two cases occurred in the mouth floor and one case in the tongue.Three A-RM cases presented as slowly growing,painless masses clinically.The masses were lobular,red-brown nodules with clear boundary.Histologically,they consisted of densely packed,large,round and polygonal cells with abundant granular eosinophilic cytoplasm.Cross striations and vacuoles were seen in the cytoplasm.Tumor cells expressed desmin and myoglobin,partially expressed SMA,MyoD1 and S-100 protein.PAS was also positive among tumor cells and could be digested by the diastasum diastace.Conclusion Histological examination is the main diagnostic basis for A-RM.For accurate diagnosis,cross striations and immunohistochemistry for myogenic proteins in cytoplasm are of pivotal importance.Radical resection is the main treatment with generally promising prognosis.