Level IA Nodal Involvement in Parotid Cutaneous Squamous Cell Carcinoma

Abstract

ABSTRACT Background The frequency of Level IA metastasis in advanced cutaneous squamous cell carcinoma (cSCC) remains undefined yet determines the oncological safety of submental island flap (SIF) reconstruction. Methods A retrospective cohort study was performed on 131 adults who underwent parotidectomy and neck dissection, identified from the Sydney Head and Neck Cancer Institute database (2000–2025): 110 with parotid metastases and 21 with preauricular cSCC. The primary outcome was pathological Level IA involvement. Results Level IA involvement was identified in 4 patients (3.6%; 95% CI, 1%–9%), with an occult rate of 0% (95% CI, 0%–3.3%). This was significantly associated with extent of neck dissection, pathological nodal status and median nodal burden (all p ≤ 0.02). Conclusions Level IA metastasis is uncommon in advanced cSCC and occurs exclusively in high‐burden nodal disease. These findings support selective omission of Level IA dissection in the clinically node‐negative neck and the oncological safety of SIF in well‐selected patients.