Recurrent Pleomorphic Adenoma of the Parotid Gland: Proposal for an LMCG Classification System and an Optimized Therapeutic Algorithm

ABSTRACT Objectives To introduce a novel clinical classification system and corresponding therapeutic strategies for parotid recurrent pleomorphic adenoma (RPA). Methods A retrospective analysis was conducted on parotid RPA cases treated by a single surgical team at Shanghai Ninth People's Hospital between January 2020 and December 2024. Based on tumor features—such as single or multiple nodules, infringement of adjacent structures, or skip metastases—as well as intraoperative facial nerve status, a classification system and corresponding treatment strategy were proposed. Results A total of 66 patients were included in the study. The majority (95.5%) presented with multinodular tumors, and 66.7% developed facial paralysis due to intraoperative facial nerve injury. The classification system termed “Localized–Moderate–Complicated–General” (LMCG) was first developed. The Localized type represents the least severe condition, while the subsequent categories reflect progressively more complex presentations. Each classification corresponds to a tailored therapeutic strategy, ranging from partial parotidectomy with or without facial nerve preservation to extensive parotidectomy combined with immediate nerve reconstruction and adjuvant radiotherapy. Conclusion The LMCG classification offers a concise framework for preoperative assessment and personalized treatment planning in patients with parotid RPA, with the potential to standardize and improve its clinical outcomes.