Clinicopathologic and Surgical Study of Pleomorphic Adenoma of the Parotid Gland: Analysis of Risk Factors for Recurrence and Facial Nerve Dysfunction.

PURPOSE

To determine whether clinicopathologic or surgical features are risk factors for recurrence and facial nerve dysfunction in pleomorphic adenoma (PA) of the parotid gland.

PATIENTS AND METHODS

The records of 198 patients surgically treated for a PA of the parotid gland from 1999 through 2013 were retrospectively reviewed to identify patients who developed a tumor recurrence. The Fisher exact test and Mann-Whitney U test were used to analyze patient characteristics between recurrent and non-recurrent PAs. Logistic regression was used to determine the risks of recurrence and facial nerve dysfunction.

RESULTS

Twenty-three patients (11.6%) developed a recurrence. Patients with tumor recurrence were notably younger than patients without recurrence. Of the 14 patients who underwent enucleation, 11 (78.6%) developed residual disease, as did 10 of 165 patients (6%) managed by a superficial parotidectomy (P < .0005). Furthermore, the risk of residual disease was 9.3 to 21.6 times higher in patients who underwent enucleation than in those who underwent a total or superficial parotidectomy. For tumor histology, recurrence was observed in 3 (15.8%) of the 19 cellular types, 18 (11.5%) of 157 classic cases, and 1 (4.8%) of 21 myxoid cases (P = .5). The risk of recurrence with positive resection margins was 49 times higher than with negative margins (P = .001).

CONCLUSION

Young age, enucleation, and positive margins are risk factors for residual pleomorphic adenoma, and surgical technique and histomorphologic features are associated with increased facial nerve dysfunction.