Comparative study of cytology and immunocytochemistry with trucut biopsy and immunohistochemistry in diagnosis of localized lung lesions: A prospective study

BACKGROUND: Percutaneous lung biopsy is now a common procedure in pulmonary medicine, and several different techniques are in use. The most common has been the use of a fine needle under computed tomography (CT) guidance combined with the trucut needle for histology. AIM: To evaluate the efficacy of fine needle aspiration cytology (FNAC) and immunocytochemistry in comparison with trucut biopsy and immunohistochemistry in patients with localized intrathoracic lesions suspicious for malignancy. MATERIALS AND METHODS: Eighty patients with localized mass lesions in the lung on imaging (chest radiograph/CT) were selected for this study over a period of 1 year. FNAC was carried out by a 22 G spinal needle after localization of the mass in the CT scan followed by guided trucut biopsy. Immunocytochemistry and immunohistochemistry were performed as and when required. RESULTS: The mean age of our study population was 57.6 years and the M:F ratio was 4.2:1. Majority of the lesions were peripheral and in the right lung. Adenocarcinoma was most prevalent (49%), followed by squamous cell carcinoma and small cell carcinoma. Cyto-histopathological concordance was seen in 60 cases (75%). The highest rate of concordance was seen in small cell carcinoma (83.3%). The overall sensitivity of FNAC in distinguishing malignant lung lesions from benign lesions was 84.2% and the specificity was 100%. The sensitivity of cytology in diagnosing small cell carcinoma was 83.3% and of non-small cell carcinoma was 65.38%. Immunocytochemistry was carried out in 34 cases, all of which were followed by immunohistochemistry. Cyto-histopathological concordance was noted in 31 of these cases (91.2%). We used the standard panel of four markers (cytokeratin-7, thyroid transcription factor-1, p63 and CD56) for all selected cases. CONCLUSION: Cytology along with immunocytochemistry is highly effective in diagnosing and categorizing lung neoplasms, producing comparable results to trucut biopsy and immunohistochemistry.