RELIABILITY OF FINE-NEEDLE ASPIRATION CYTOLOGY FOR DISTINGUISHING BETWEEN CARCINOMA, LYMPHOMA AND SARCOMA - THE INFLUENCE OF CLINICAL INFORMATION

To investigate interobserver variation of fine needle aspiration (FNA) cytological diagnosis with respect to distinguishing between carcinom a, sarcoma and lymphoma, a set of 80 randomly sampled slides was rando mized twice and read 'blindly' by five cytopathologists. In the first round the slides were read without any information, and in the second round clinical information was provided. Histology was used as a refer ence standard. In the first round, the positive predictive values for the cytological diagnosis of carcinoma, sarcoma and lymphoma were 93%, 94% and 86% respectively. In the second round the positive predictive values for the cytological diagnoses of carcinoma, sarcoma and lympho ma were 95%, 99% and 99%, respectively. Interobserver variability, tes ted with weighted kappa scores (range 0.73-0.92) between histological and cytological diagnosis, was low. The most accurate FNA cytologic cl assification was obtained when the clinical context was known.