Carcinoma ex pleomorphic adenoma
Carcinoma ex pleomorphic adenoma (ca ex PA) is a type of cancer typically found in the parotid gland. It arises from the benign tumour pleomorphic adenoma. Its prognosis depends on the stage. Early tumours have essentially a benign behaviour. Signs and symptoms. The signs and symptoms are similar to other malignant salivary gland tumours; however, it may have been preceded by an appreciable mass that was long-standing and did not appear to be growing. Findings that suggest a malignant salivary gland tumour include rapid growth, facial weakness (due to facial nerve compression), pain, skin ulceration , fixation of the mastoid tip and parasthesias. Diagnosis. Carcinoma ex pleomorphic adenoma is diagnosed by examining it under the microscope with consideration of the individual history. In approximately 75% of cases ca ex PAs arise in a pleomorphic adenoma that is apparent when the tumour is excised. In the other approximately 25% of cases the individual had a pleomorphic adenoma excised previously and the diagnosis is made based on (1) the presence of a carcinoma, and (2) the history of a pleomorphic adenoma at that location.