A comparison of the effectiveness of malignancy detection in body fluid examination by the cytopathology and hematology laboratories

Background. - Body fluid specimens in many institutions are submitted for cytologic examination as well as for examination in a clinical microscopy or hematology laboratory. The cytology laboratory is generally seen as the standard for detection of malignancy, whereas the clinical microscopy laboratory is often depended on predominantly for cell counting and categorization. Methods. - To analyze the effectiveness of the hematology laboratory at detecting malignant fluids, this study retrospectively analyzed reports on 397 body fluid specimens (cerebrospinal, pericardial, peritoneal, and pleural) that were concurrently submitted over a 12-month period to both the cytopathology laboratory and the hematology laboratory. Results. - Thirty-seven (9.3%) of the cases were diagnosed as malignant by at least one of the two examinations. The cytopathology examination reported 27 (73%) of the 37 malignant cases as malignant and 30 (81.1%) as at least atypical (27 malignant and 3 inconclusive), and the hematology examination reported 34 (91.9%) as malignant and 36 (97.3%) as at least atypical. A concordant malignant diagnosis was given by both laboratories in 24 (64.9%) of the 37 cases. Conclusions. - These results show that examination of specimens by the hematology laboratory can provide a highly sensitive diagnostic evaluation in addition to its more customary role of providing timely cell counts.