Recurrent pleomorphic adenoma: Epidemiology and surgical challenges; a single tertiary center experience.

Introduction: Despite being less common in recent years, recurrent pleomorphic adenoma still poses a surgical challenge, especially after improper surgery.

Methods: We retrospectively recruited all patients with recurrent pleomorphic adenoma and Carcinoma ex pleomorphic adenoma from February 2007 to April 2024 who were operated upon in a tertiary cancer center. Epidemiological, radiological, and pathological data, risk factors, details of surgical treatment, and surgical/oncological outcomes were analyzed.

Results: 35 patients with recurrent pleomorphic adenoma were recruited, 19 were women (54.3 %) with the parotid gland being the most affected site in 74.3 % followed by the submandibular gland in 20 %. Only 11 patients (31.4 %) underwent surgery for the primary tumor in our center, and of interest that 48.6 % of the total cohort underwent simple enucleation for their primary tumors. The interval between resection and recurrence was shortened with frequent recurrences. Again, 71.4 % of facial nerve injuries had a history of simple enucleation for their primaries. 3 cases of Carcinoma ex pleomorphic adenoma were reported, representing 1.4 % of the patients with parotid pleomorphic adenoma in the study period, and was associated with young age and long-standing recurrence.

Conclusions: Surgery is the cornerstone treatment for both primary and recurrent pleomorphic adenoma. Inadequate primary surgery, long-standing lesions, multiplicity, and fragmentation may be associated with facial nerve injury. Reconstructive flaps may be needed to cover the large resultant defects. Surgery for pleomorphic adenoma should be done by adequately trained surgeons. Radiation as an adjuvant treatment needs to be used frequently, especially through a multidisciplinary approach. Carcinoma ex pleomorphic adenoma, being rare, is demanding in its management with a poor prognosis.