Reliable EGFR mutation testing in ultrasound-guided supraclavicular lymph node fine-needle aspirates: a cohort study with diagnostic performance analysis

INTRODUCTION 15-30% of patients with lung cancer will have supraclavicular and cervical lymphadenopathy (SCLN). Ultrasound (US)-guided fine-needle aspiration (FNA) cytology is regarded as an effective diagnostic tool in small size lymph nodes (LNs) and impalpable positron emission tomography detected nodes. We evaluated our diagnostic service performance in relation to the adequacy of samples for epidermal growth factor receptor (EGFR) mutation. METHODS Retrospective data analysis from electronic records, searching for all suspected lung cancer referrals that underwent US of the neck±FNA, over a continuous period of 4 years. RESULTS Of 306 cases with suspected lung cancer referred to our department for US FNA of SCLN, 228 patients underwent the procedure. Of the remaining 78 patients, LNs were not detected in 52 cases and appeared benign in 26. Cytological diagnosis was established in 171 patients (75%) for treatment decisions without further investigations. The remaining 57 patients had further investigations; 45 reconfirmed the US-guided FNA diagnosis. The average LN size was 12.9 mm, and positive cytology was obtained in LNs ranging from 3 to 45 mm. Of 57 adenocarcinoma cases, 34 were tested for EGFR confirming 4 positive, 25 negative and 5 insufficient samples. No complications were recorded. CONCLUSIONS US-guided FNA of SCLN remains an important diagnostic tool in lung cancer. Adequate tissue can be obtained for reliable diagnosis from LNs and for EGFR mutational analysis, without the need for more invasive and expensive investigations in more than 80% of cases.