atypical pleomorphic adenoma
Monday 3 October 2016
Pleomorphic adenoma is the most common salivary gland neoplasm and infrequently undergoes malignant transformation.
Carcinoma ex pleomorphic adenoma is typically an infiltrative neoplasm with features of cellular pleomorphism, high mitotic activity, peri-neural and vascular invasion.
More recently, sub-groups of pleomorphic adenoma have been described exhibiting vascular invasion and features of malignancy without evidence of extra-capsular extension.
In a study following a review of 100 consecutive pleomorphic adenomas removed from the major salivary glands, 4 cases with atypical histological features were found. Three tumours exhibited features of dysplasia/carcinoma without evidence of extra-capsular invasion and a further case demonstrated benign vascular invasion. There were no clinical features suggestive of the atypical nature of these neoplasms, though fine needle aspiration cytology (FNAC) was suspicious of a malignancy in 2 cases and CT scan in 1 case. (16540285)
Atypical features in pleomorphic adenoma—a clinicopathologic study and implications for management. Ethunandan M, Witton R, Hoffman G, Spedding A, Brennan PA. Int J Oral Maxillofac Surg. 2006 Jul;35(7):608-12.