Rare Adult Masseteric Rhabdomyosarcoma and a Review of the Literature

BACKGROUND: Rhabdomyosarcomas (RMSs) are a group of soft-tissue malignant tumors which derive from primitive skeletal muscle tissue that mainly affect children and adolescents. RMSs are very rare in adults, where they are usually located in the extremities. CASE PRESENTATION: A previously healthy 32-year-old male presented at our ENT (ear, nose and throat) outpatient clinic after experiencing a parotid region swelling for 2 months. The patient was treated surgically by excising the mass and by modified radical ipsilateral neck dissection. Histological and immunohistochemical examination indicated masseteric alveolar RMS with lymphatic metastasis. The patient received radiochemotherapy, and he is still alive with no evidence of disease spread 1 year after diagnosis. CONCLUSION: This is the first case of a masseter alveolar RMS to be reported in the literature in a patient older than 25 years; it highlights the broad spectrum of neoplasms that cause parotid region swellings and the importance of considering rare tumors during differential diagnosis.