Cell blocks histopathology versus FNA cytology in diagnosis of primary malignant lung mass: A comparative study

Abstract

Background and objective: Fine needle aspiration cytology with cell block preparation is widely used for preoperative confirmation of solitary lung mass and classification of the histologic types. This study aimed to highlight the importance of cell-block preparation in the diagnosis of primary malignant lung lesion by comparing cytomorphological preservation on paired cell block and conventional fine needle aspiration samples. Methods: During January 2012 to October 2015, a total of 100 cases with solitary lung mass were included, either visited Rizgary Teaching Hospital or Walfare private hospital. All the patients had undergone fine needle aspiration and cell block preparation under a CT-guide. Results: The samples were evaluated by the fine needle aspirations and cell blocks preparations from primary lung lesion under a CT-guide. 74% were male, and the majority of them were in the sixth and seventh decade. Squamous cell carcinoma was the most common histologic type consisting 42% of the studied cases, followed by adenocarconima (31%), small cell carcinoma (19%) and the remaining 8% were large cell carcinomas. In the assessment of agreement of cellularity between the two methods of sample preparation, cell block served better than fine needle aspiration (P = 0.715). However, this difference was statistically non-significant. A significant relation was found for morphology which was preserved in fine needle aspiration samples better than that in cell block samples (P <0.05). In contrast, all cell block samples displayed a statistically highly significant architectural preservation compared to fine needle aspiration samples (P <0.001). The sensitivity and specificity of the present study were 98.46%, 99.2% respectively. Conclusion: Direct fine needle aspiration smears and cell blocks complement each other, and our results indicate that both are needed in the diagnostic work-up of patients with a primary malignant lung mass.