Abstract
We report a rare case of adenoid cystic carcinoma with malignant transformation from pleomorphic adenoma 24 years after primary surgery. The patient was a 60-year-old man who was admitted for treatment of a tumor of the right upper gingiva. He had previously undergone two operations for a right lacrimal gland tumor. In the f irstsurgery, the tumor was removed by Krönlein's operation and histology of this tumor showed a pleomorphic adenoma. Twenty-four years later, he complained of exopthalmos of the right eye. Computed tomography and magnetic resonance imaging revealed that a tumor occupied the superior temporal portion of the right orbit and extended into the cranial cavity. Histopathological diagnosis of this tumor at the second operation was adenoid cystic carcinoma. After 10 months, however, the tumor grew into the maxillary sinus and oral cavity. The patient received radiotherapy and three courses of superselective intra-arterial chemotherapy. Although the tumor was reduced temporarily, it gradually became larger and eventually led to death.
In rare instances, pleomorphic adenoma can undergo malignant transformation, particularly following incomplete and frequent surgical removal.
We reported here such a rare case.
