Subtyping of Papillary Renal Cell Carcinoma (PRC) by Fine Needle Aspiration (FNA): A Reliable Approach To Providing Valuable Prognostic Information.
Graham E Parks, Sahussapont J Sirintrapun, Kim R Geisinger. Wake Forest University School of Medicine, Winston-Salem, NC
Background: Studies have shown prognostic value in the subclassification of PRC. Type 1 has papillae with single layers of small cells with minimal cytoplasm, and type 2 has papillae lined by cells with ample, eosinophilic cytoplasm. Poor prognosis has been associated with high stage, high nuclear grade, subtype 2, absence of foam cells, and abundant fibrous stroma. Histologic subtyping and recognition of high grade features on FNAs thus provides valuable and immediate prognostic information. While the features of PRC in FNAs have been described, little has been done to determine whether subtyping or grading may be possible on FNA alone. In many cases, corresponding core needle biopsy (CB) or cell block material may not be obtained.
Design: Case files were searched from 2000 – 2010 for renal FNAs with the diagnosis PRC; 65 cases were identified, 43 had corresponding CBs, with 24 available for review. The FNA (DiffQuick and Papanicolau-stained) was reviewed by a cytopathologist, and CBs by a genitourinary pathologist in an independent, blinded review. Each case was evaluated for subtype (1-2), nuclear grade (1-4), and high vs. low grade.
Results: CB and FNA were identified with type 1 (upper panels), and type 2 features (lower panels).
Nine CB (36 %) were found to be type 2. The sensitivity and specificity for type 2 on FNA were 66.7% and 93.3% respectively. When nuclear grades were grouped as high (3 & 4) and low (1 & 2), the sensitivity and specificity for high grade features on FNA were 100% and 83.3% respectively. Good correlation was observed with quantitative (1-4) grading as well: in 70.8% of cases the nuclear grade was an exact match, and in 20.8% of cases the grade on FNA was higher (four cases higher by one, one case higher by 2). There were only two cases (8.3%) in which grade on FNA was lower than that determined with the CB.
Conclusions: Based on a limited sample set, recognition of histologic subtype 2 and high grade features in FNAs of PRC is possible, reliable, and provides valuable, rapid prognostic information. These initial findings suggest that a larger study may be informative, and that FNAs of PRC have value complementary to CB.
Category: Genitourinary (including renal tumors)
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 86, Wednesday Morning