Natural history of recurrent pleomorphic adenoma: implications on management.

BACKGROUND

Treating recurrent pleomorphic adenoma (RPA) aims to reduce risk of malignant transformation (MT) while avoiding facial nerve injury. Our objective was to systematically investigate this natural history of RPA and address the current rational for its treatment.

METHODS

The follow-up data of two nationwide series of PA was pooled with a focus on risk of MT and analyzed against the literature.

RESULTS

The combined nationwide data (n = 9003 PA patients) showed 3.1% with first recurrence of which 6.2% were malignant. In the literature first RPA rate was >7% at 20 years follow-up. MT occurred in 0% to 7%, and facial nerve damage increased from with each surgery 3% to 16% at first RPA to 18% to 30% at second RPA.

CONCLUSIONS

RPA showed a characteristic course with surgery being unreliable and damage to the facial nerve. The risk of MT was low. This might give flexibility towards a more conservative approach of management.