Changing pattern of bronchogenic carcinoma: A statistical variation or a reality?

Objectives: To document the various CT appearances of bronchogenic carcinoma with histopathologic correlation, to identify changing trend in the radiographic pattern of bronchogenic carcinoma, if any and to evaluate the role of CT in staging of bronchogenic carcinoma was also evaluated. Materials and methods: A prospective study of 81 patients over a period of 2 yrs with clinical and or radiological suspicion of bronchogenic carcinoma and confirmed histopathogical diagnosis was undertaken with CT of the thorax using 10 mm collimation sections from the level of lung apices to the diaphragm and routinely included the adrenals. Results: Squamous cell carcinoma is the most common histologic subtype followed by adenocarcinoma and small cell carcinoma. There was a definite male preponderance with smoking being the most common risk factor. Adenocarcinoma is presenting predominantly as central tumor(70.5%) Squamous cell carcinoma is presenting predominantly as peripheral tumor (52.7%). Conclusion: Computed tomography is the modality of choice for evaluating bronchogenic carcinoma because of its better spatial resolution. CT provides precise characterization of the size, contour, extent and tissue composition of the suspicious lesion. If the lesion represents a bronchogenic carcinoma, CT serves as a part of the staging process to assess the extent of the disease. The radiologic presentation of adenocarcinoma and squamous cell carcinoma is showing a changing pattern. In our study, adenocarcinoma is presenting predominantly as a central tumor and Squamous cell carcinoma is presenting predominantly as a peripheral tumor. This relative increase in the percentage of centrally located adenocarcinoma is a statistical variation or a reality needs to be evaluated further.