Satellite tumors surrounding primary pleomorphic adenomas of the parotid gland.

The occasional local recurrence of benign pleomorphic adenoma (PA) has generally been attributed to the vulnerability of the tumor capsule. Although some reports have also noted the presence of satellite tumors associated with PA recurrence, only few reports have focused on this issue. We paid special attention to the satellite lesions apart from the main tumors and discussed their frequency, origin, nature and the ways of treating them. A total of 108 specimens of primary parotid gland PA resected at the Okayama Saiseikai General Hospital from 1988 to 2008 were microscopically reviewed. Four (3.7%) patients displayed a main mass with satellite tumors in a single parotid gland. The immunohistochemical analysis of p53 and Ki-67 index showed no distinct difference between PAs with satellite tumors and those without. Satellite tumors surrounding the main mass of parotid PA is relatively rare. In most cases, such satellite tumors will arise from capsular perforation of the primary tumor cells. Preoperative evaluation to recognize the existence of satellite tumors would be important and capsular dissection should be discouraged. We could not find any evidence suggesting that primary PA with satellite tumors could be more biologically aggressive than those without.