Radiology contributes to better cytological diagnosis of lung tumors

Cytology is well established and widely accepted method to diagnose lung tumors. However, cytological changes of malignant cells can be so subtle that cytopathologists cannot always diagnose with certainty. In such cases, some cytopathologists believe that radiological assessment is important for correct cytological diagnosis. However others deny the importance of radiological information, because they believe it could not change the cytological assessment. This study mainly aimed to clarify how radiologist's comments affect cytological diagnosis of lung tumors.

Of 201 patients who underwent cytological examinations, 131 and 57 patients were diagnosed with malignant and benign lung lesions, respectively. Study coordinators randomly selected 60 cytological slides each of the benign and malignant lesions. A radiologist graded their CT images by using a 5-point confidence scale. Three cytotechnologists assessed the 120 cytological slides twice on the basis of a 5-grade classification: first before and then after obtaining radiologist's grading. Receiver operating characteristic analysis was performed. The Az values, sensitivities, and specificities of the cytological diagnoses were calculated for comparing the results before and after obtaining radiologist's grading.

The mean Az value for cytological assessment after obtaining radiologist's grading (0.88) was significantly higher than that before obtaining radiologist's grading (0.78). The mean sensitivity of cytological assessment after obtaining radiologist's grading (77%) was significantly higher than that before obtaining radiologist's grading (67%).

Radiological assessment, together with a radiologist's confidence, improves cytological diagnoses of lung diseases. Thus, the importance to positively provide radiological assessment to cytopathologists should be considered by all clinicians.