Histopathological Validation of Clinical Palpation vs. Ultrasonography for Cervical Lymphadenopathy in Oral Squamous Cell Carcinoma: An Ambi-directional Cohort of 1,690 Nodes from Rural Karnataka, India

Background: Cervical lymph node metastasis reduces OSCC 5-year survival by 50%; accurate preoperative detection via clinical palpation vs. grayscale ultrasonography (USG) remains critical for treatment planning.​ It is established that better diagnostic resources are available that provide a more accurate assessment of cervical lymphadenopathy; however, they may not be feasible in low resource regions where the incidence of OSCC is high. Aim and objective: The study aims to assess the diagnostic accuracy of clinical palpation with Gray-scale 2-D USG using the Histopathology assessment as the benchmark. The objective is to ascertain if USG is required in addition to clinical palpation in low-resource centers. Methods: Retro-prospective analysis of 300 patients with biopsy-proven OSCC undergoing tumor resection and neck dissection at a Karnataka tertiary center; clinical palpation and USG (7-12MHz linear probe) assessed 1,690 cervical lymph nodes, correlated with post-operative histopathology (gold standard) to assess sensitivity, specificity, NPV and PPV.​ Results: Of all subsites, buccal mucosa (61%) was most common subsite; the mean age 45-55 years, male:female ratio of predilection was 2.4:1. USG demonstrated superior sensitivity (73.8%) compared to palpation (58.3%), NPV 92.7% vs. 87.0% respectively, with specificities 63.4% vs. 67.8% and PPV 27.9% vs. 30.8% respectively. The lymph node Level Ib/II demonstrated largest accuracy in assessment. Conclusion: Grayscale USG can act as an added supplement to clinical palpation for reliable N0 neck identification in OSCC, supporting AJCC 8th staging protocols in resource-limited settings.​​