Abstract: Objective To investigate the diagnostic value of histopathology and imprinted cytology for percutaneous lung biopsy under CT guidance in qualitative diagnosis of lung tumor. Methods A total of 363 cases of lung biopsy specimens under CT guidance were reviewed. The difference between histopathology，imprinted cytology and the combinational diagnosis method were analyzed. Results Among the 363 cases，the histopathology revealed 119（32. 78%）malignant tumors，13（3. 61%） suspicious malignancy，4（0. 83%）atypical cells and 227（62. 78%）negative findings，whereas the corresponding numbers for imprinted cytology diagnosis were 98（27. 50%），14（4. 72%），12（1. 94%） and 239（65. 84%）. For qualitative diagnosis of lung malignant tumors，the sensitivity and specificity of histopathology were 97. 14%（136/140）and 100%（223/223），while the corresponding numbers for imprinted cytology were 85. 71%（120/140），98. 21%（219/223），and those of the combinational method were 99. 29%（139/140），100%（223/223），respectively. The difference was statistically significant within the sensitivity between the two methods（P = 0. 001）. The difference was not statistically significant between the histopathology and the combinational method within the sensitivity （P = 0. 367），however，three cases missed by histopathology were effectively supplemented by cytological diagnosis. The difference was statistically significant between the imprinted cytology and the combinational method within the sensitivity（P = 0. 000），while the difference was not statistically significant within the specificity between the two methods（P = 0. 013）. Conclusion The examination of histopathology and imprinted cytology for CT-guided percutaneous lung biopsy can complement each other，and may provide important value for the qualitative diagnosis of pulmonary tumor.

Key words: lung tumor, CT-guided, histopathology, imprinted cytology