Histopathologic Analysis of Parotid Pleomorphic Adenoma: Resection Margin and Capsular Characterisitcs

Lee, Min Young; Lee, Sang Joon; Kwon, Mi Seun; Chung, Phil Sang

Abstract

BACKGROUND AND OBJECTIVES
Pleomorphic adenoma is the most common benign neoplasm of the parotid gland. It is well known that margin involvement, pseudopod and satellite nodule are factors contributing to recurrence. In this study, we investigated the pathologic characteristics in the parotidectomy specimen of the pleomorphic adenoma.
SUBJECTS AND METHOD
From January 2002 to July 2007, 45 patients who were diagnosed as pleomorphic adenoma of the parotid gland were selected, and their pathologic slides were reviewed by a pathologist. The narrowest resection margin and capsular characteristics such as incomplete capsule, pseudopod and satellite nodule were checked. Also, the relationship between pathologic subtype and the capsular characteristics was analyzed.
RESULTS
The narrowest resection margin was related to size and location of the tumor. Smaller tumor had larger resection margin with stastistical significance and tumor located in the superficial lobe had larger resection margin. In pathologic subtypes, capsular characteristics such as incomplete capsule and satellite nodule were more frequent in myxochondroid type. Even in small tumor (<2 cm), capsular characteristics such as satellite nodule and pseudopod were not infrequent.
CONCLUSION
Average resection margin was 4 mm but variable. Because the incidence of satellite nodule, pseudopod and incomplete capsule is about 30% in parotid pleomorphic adenoma, the resection of the tumor containing normal parotid tissue is important to reduce the risk of recurrence.