Parotid lymph nodes in primary malignant salivary neoplasms.

PURPOSE OF REVIEW: To review the literature on parotid lymph nodes and their involvement in primary malignant epithelial salivary gland neoplasms (PMESGN). The parotid gland has two identifiable lymphatic systems - extraglandular and intraglandular both topographically separate but functioning as a single unit. RECENT FINDINGS: The publications available have concentrated on intraparotid lymph nodal metastatic (IPLN) disease only. SUMMARY: The data reported was retrospective and observational. The limitations encountered was the variability of extent of the parotid surgery, unclear evaluation of IPLN limited or inconsistent follow-up periods, small subgroups limiting the explanatory power and the multivariate analysis. One multicentric publication reported on 289 patients with parotid PMESGN treated by surgery between 1995 and 2018 at four centres: three Italian and one in the United Kingdom. IPLN+ was proven in 22.1%, preoperative imaging failed to identify occult IPLN+ in 20.1%, IPLN+ and cervical nodal metastasis (cpN+) was 47.4% and cpN+ was 100% in patients bearing greater than 4 IPLN+ nodes. A multicentric prospective study is required detailing preoperative imaging, using a standardized surgical management, pathological specimen search, histopathological grading and patient outcome analysis specifically designed to resolve the role of IPLN in patients diagnosed with PMESGN.