Recurrent Pleomorphic Adenoma of the Parotid Gland in Pediatric and Adult Patients:Value of Multiple Lesions as a Diagnostic Indicator

OBJECTIVE: Recurrent pleomorphic adenoma of the parotid gland is a significant problem. Rates have been as high as 40% in some series of patients who have undergone surgery for the primary lesion. In the imaging literature, anecdotal case reports show multiple lesions in recurrent pleomorphic adenoma. Our aim was to analyze the imaging of a series of patients to determine the reliability of multiple lesions as a tool in diagnosing recurrent disease. MATERIALS AND METHODS: Medical records of the patients with recurrent pleomorphic adenoma of the parotid gland referred to our institution were retrospectively reviewed. Before the second surgery, MR imaging had been performed in 15 patients. We retrospectively reevaluated and scored the MR imaging studies with particular attention paid to the location and number of the lesions and the remaining parotid gland tissue. RESULTS: On the basis of imaging findings, eight patients underwent enucleation, superficial parotidectomy had been performed in four patients, and three patients underwent total parotidectomy. For our group, the lesions were multiple in 73.3% of patients. CONCLUSION: To our knowledge, we present the first large series of imaging studies in recurrent pleomorphic adenoma of the parotid gland. Our findings show that recurrent pleomorphic adenomas are most likely to be multiple. Such multiplicity of lesions is a reliable diagnostic indicator of recurrent disease.