Objectives: Postoperative prognosis of sinonasal adenocarcinoma (SNAC) is closely related to local recurrence. Our objective was to identify subclinical anterior skull base (ASB) invasion, and to evaluate the impact of endoscopic transnasal craniectomy on SNAC staging and prognosis. Methods: Retrospective study conducted from 2010 to 2023, including 33 patients, comparing 2 groups: conservative endoscopic sinus surgery (ESS) and complementary endoscopic resection with transnasal anterior skull base craniectomy (ERTC). Histopathology, overall survival (OS), recurrence-free survival (RFS), complication rates, surgery time and hospital stay were analysed. Results: Histopathology revealed malignant invasion in 36.8% of ASB surgical specimens, despite the absence of pre- or intraoperative evidence of skull base invasion. All were low-grade tumours, with 57.1% previously classified as cT2. ERTC was associated with an improvement in RFS, although not statistically significant, with a greater incidence of complications, but no impact on OS. Conclusions: This study provides the first significant evidence of frequent subclinical invasion of the ASB in cT2 cases. These findings raise important questions regarding the management of cT2 lesions. Should systematic biopsies of the anterior skull base be taken? Should a skull base resection be discussed in selected patients? Further studies with larger samples are necessary to better define the risk-benefit ratio of ERTC in low-stage SNAC prognosis.
Mahdjoub et al. (2026) studied this question.