The Value and Limitations of Cell Blocks in Endobronchial Ultrasound-Guided Fine-Needle Aspiration Cytology: Experience of a Tertiary Care Center in North India

BACKGROUND: Endobronchial ultrasound (EBUS)-guided fine-needle aspiration cytology (FNAC) is recommended for diagnosing bronchial neoplasms and evaluating mediastinal lymph nodes. However, it may not be possible to subtype or definitely categorize many bronchial neoplasms on FNAC smears alone. Obtaining adequate diagnostic material is often a problem. In such cases, cell blocks made from FNAC material may serve as a useful adjunct. Aim: To study the value and limitations of cell blocks in adding diagnostic information to EBUS guided FNAC smears. MATERIAL AND METHODS: One hundred and eighty-five cases of EBUS guided FNAC having concomitant cell blocks were reviewed. The cases were evaluated for the extent of adequacy, of definite benign/malignant categorization and of definite subtyping in malignant tumors in these cases. The proportion of cases in which cell blocks added information to FNAC smears alone for the above parameters were calculated. RESULTS: Cell blocks provided additional information in 31 out of 185 cases. Cell blocks were necessary for subtyping 24/59 malignant tumors, definite categorization into benign and malignant in 10/140 adequate samples, and increasing adequacy in 6/185 total samples. A total of 45 samples were inadequate in spite of adding information from cell blocks to smears. CONCLUSION: Cell blocks added clinically significant information to EBUS guided FNAC and should be used routinely. To make it more useful, alternative methods of cell block preparation (including proprietary methods) may be evaluated.