KRAS mutation results were moderately high for the detection of KRAS mutations with cytomorphological features of adenocarcinomas (12,13), but are in accordance with the recently reported prevalence of NSCLC patients with KRAS mutations (27%) detected using COLD-PCR (14) and 36.9% KRAS mutations detected in malignant pleural effusion of lung adenocarcinoma in a Dutch population (15). Here, KRAS is linked to adenocarcinoma.