Lung, bone, skeletal muscles and cutaneous metastases from adenoid cystic carcinoma of the parotid gland: a case report and review of the literature

Adenoid cystic carcinoma is the second most common malignancy of the major and minor salivary glands after mucoepidemoid carcinoma. The risk of distant metastases is approximately 20–50%. Although bone, the central nervous system and the other organs may become involved, the lungs are favored sites for metastases. Skeletal muscle and cutaneous metastases from adenoid cystic carcinoma of the parotid gland are extremely rare. In this case, a 40-year-old man with lung and bone metastases followed by skeletal muscle and cutaneous metastases from adenoid cystic carcinoma of the right parotid gland is presented.