Recurrent benign parotid tumours: The lesson not learnt yet?

Background: To study the behaviour of recurrent benign parotid tumours, recurrence characteristics and problems faced with the removal of these lesions. Methods: We reviewed the charts of the work of a single surgeon between 1971 and 1996. Results: There were 24 patients (13 women, 11 men with a mean age of 44 years at re-operation. Mean follow-up period was 10 years (range 1-22 years). There were 21 recurrent pleomorphic adenomas, two monomorphic adenomas and one patient with recurrent oncocytoma. Nine patients had solitary recurrence with a mean size of 14 mm, 15 patients had multiple recurrences with a mean size of 8 mm. There was malignant transformation of a previously benign lump in one patient. Three patients presented with a second or third recurrence. Overall facial nerve paralysis was 53% (38% temporary and 15% permanent). Frey's syndrome occurred in four patients (17%). Conclusions: Recurrent benign parotid tumours are uncommon if superficial parotidectomy (SP) is the performed initially: recurrence rates are between 0-4%. The recurrences are usually slow growing and require lengthy follow-up. Pre-operative diagnosis of a lump in the region of previous excision is useful in treatment planning. Malignant transformation in previous benign lump should be considered and fine needle aspiration biopsy may help in diagnosis. Facial nerve injury is more likely if the tumour is deep, in multiple sites or involves extensive scar tissue. Radiotherapy is controversial, it should be considered if there has been tumour spillage following re-operation.