CLINICAL-SIGNIFICANCE OF AN INCONCLUSIVE CYTOPATHOLOGIC DIAGNOSIS .1.POSITIVE PREDICTIVE VALUE

We retrospectively analyzed the pathology database of 1,057 patients a t Duke University Medical Center who received an inconclusive cytopath ologic diagnosis during the Jive-year period 1984-1989 in an attempt t o answer the question, what is the significance of a cytopathologic di agnosis of ''atypical cells are present that are suspicious for, but n ot diagnostic of, malignancy?'' We identified 1,110 cytologic specimen s from all body sites receiving this diagnosis, and of them, 805 (73%) had a follow-up specimen from the same anatomic site that was definit ive as to the presence or absence of malignancy; 305 (27%) had no foll ow-up specimen. Of the follow-up specimens, 596 (74%) were histopathol ogic specimens, and 209 (26%) were cytopathologic. Specimens from the respiratory tract accounted for 51% (563) of the cases, and the positi ve predictive value (PPV) of an inconclusive diagnosis at this site wa s 85%. Of the remaining specimens, those from the urinary (10%) and ge nital (8%) tracts were the most common, and the PPVs of an inconclusiv e diagnosis at these sites were 83% and 61%, respectively The overall PPV of an inconclusive cytologic diagnosis from all body sites teas 80 % and ranged between 57% and 93%, depending on the anatomic site.