The role of elective neck dissection in parotid acinic cell carcinoma: a systematic review.

Acinic cell carcinoma (AciCC) is a rare parotid malignancy treated by parotidectomy with or without a neck dissection depending on clinical or radiographic neck node involvement. The role of elective neck dissection (END) in the clinically node-negative neck, intended to address occult lymph node metastases (OLNM), remains contentious. This review was conducted per PRISMA 2020. Searches through PubMed, EMBASE, and CINAHL were conducted up to May 2025. Data extraction focused on survival, recurrence outcomes and OLNM. Risk of bias was assessed using the Newcastle-Ottawa Scale. From 741 screened articles, 13 retrospective cohort studies were included. Across 2,646 parotid AciCC cases, 788 underwent END, 77 demonstrating OLNM. Marked heterogeneity was observed among studies, with reported OLNM rates ranging from 0% to 37.5% and a weighted mean of 9.8%. High-grade transformation was associated with poorer survival; advanced T-stage showed a less consistent association, and grade-stratified nodal differences were generally based on small samples and not statistically significant. Routine END is not supported in low-grade, early-stage AciCC. High-grade transformation is an adverse prognostic factor; the independent value of advanced T-stage is less certain, resting largely on some single cohort studies. END has not been shown to improve survival, and comparisons are confounded by indication. Any role in higher-risk disease remains uncertain and should be individualised rather than routine. Multi-institutional registries with standardised reporting are needed to strengthen the evidence.