We report a case of asynchronous triple malignant neoplasms limited to the jaw. A 57-year-old woman had an operation for right maxillary squamous cell carcinoma, then underwent a second operation for right submandibular mucosal squamous cell carcinoma at 59 years of age. These two tumors were treated well by the operations and chemotherapy. No radiation therapy was performed. Four years after the second operation, a small granulation was found at the edge of the operated maxillary bone. It gradually enlarged to 3cm in size in a couple of months. Surgical therapy was performed and a histological examination revealed an osteosarcoma of the maxillary bone. Including this osteosarcoma, she had three different cancers limited to the jaw. Triple malignant neoplasms are not rare. However, this case was extremely rare because three asynchronous malignant neoplasms were limited to the jaw.
