Identification of Key Cytomorphologic Features of Renal Medullary Carcinoma in Fine Needle Aspiration Biopsy

Abstract

(HGUC) (1) and used these features to identify atypical urothelial cells of undetermined significance (AUC-US) specimens more likely to have HGUC on follow-up (2). We now analyze the four morphological criteria individually to see which are most predictive of HGUC. Materials and Methods: The hospital laboratory information system was searched for cytology specimens that were diagnosed as AUC-US from July 1, 2007 to June 30, 2009. Approximately 670 specimens were identified. Of these specimens, 275 were used in this study. The specimens were classified by clinical indication (158 surveillance for neoplasia and 117 for hematuria). Two pathologists (CJV and DLR), blinded to outcome and indication, separately scored each of the AUC-US specimens for previously-identified cytologic criteria (irregular nuclear borders, nuclear hyperchromasia, increased nucleus-to-cytoplasm ratio, and anisonucleosis) most commonly found in AUC-H specimens. The specimens were then matched with the follow-up biopsy or clinical outcomes, which were tracked over the 18 months following the July 2009 cutoff for inclusion in the study. Results: The ability for individual morphological criteria to predict HGUC was strikingly different between the hematuria and surveillance groups (Table 1). Each of the four individual morphological characteristics was statistically significant (P < 0.01) for predicting HGUC in all-comers and surveillance patients but not for hematuria patients (Table 2).