Limited Sensitivity of Ultrasound-Guided Fine-Needle Aspiration Cytology for Occult Nodal Metastases in Early-Stage Oral Squamous Cell Carcinoma

BACKGROUND: Ultrasound-guided fine-needle aspiration cytology (US-FNAC) is commonly used in the diagnostic work-up of head and neck cancer, but its ability to detect occult lymph node metastases in early-stage oral squamous cell carcinoma (OSCC) with a clinically negative neck remains unclear.

METHODS: A retrospective analysis was performed in 578 patients with early-stage OSCC (cT1-3N0) who underwent US-FNAC prior to surgery. Histopathology, sentinel lymph node biopsy, and follow-up were used as reference standards.

RESULTS: Occult nodal metastases were found in 179 patients (31.0%). US-FNAC showed low sensitivity (15.9%) and a negative predictive value of 72.9%, resulting in 149 false-negative cases (25.8%). Specificity (99.5%) and positive predictive value (90.3%) were high, with only 2 false-positive results.

CONCLUSIONS: In patients with early-stage oral cavity squamous cell carcinoma and a clinically negative neck, US-FNAC demonstrates high specificity but limited sensitivity and negative predictive value. These findings indicate that US-FNAC alone is insufficient to exclude occult nodal metastases and should be regarded as an adjunctive diagnostic tool rather than a stand-alone nodal staging strategy.