A Panel of CK7, CK20 and p63 Using the Cell-Transfer Technique Is Useful in the Fine-Needle Aspiration Diagnosis of Metastatic Urothelial Carcinoma.
Howard H Wu, Kelly J Jones, Harvey M Cramer. Indiana University School of Medicine, Indianapolis
Background: Immunocytochemistry (ICC) performed on the cell-transferred fine-needle aspiration (FNA) smears is extremely helpful if conventional cell blocks lack adequate cellularity. Multiple immunostains can be performed on single cellular smear using the cell-transferred technique. Distinguishing high grade metastatic urothelial carcinoma (MUC) from non-keratinizing squamous cell carcinoma of the lung (NKSCCL) by cytomorphology alone can be difficult. The application of ICC on the cell-transferred smears is helpful to differentiate MUC from NKSCCL.
Design: A computerized search of our case file was performed for a 3-year period to identify all cases of MUC and NKSCCL with adequate materials for study. A panel of immunostains including CK7, CK20 and p63 was performed on the cell-transferred FNA smears as well as on sections from the corresponding original primary tumor. The concordant rate between the smears and the formalin-fixed tissue from the original tumors was calculated. Comparison of the immunostaining results of the MUC and NKSCCL cases was analyzed using the t-test.
Results: A total of 13 cases of MUC and 12 cases of NKSCCL were identified. The concordant rate of the immunostaining performed on the cell-transferred FNA smears and the formalin-fixed original tumor tissue was 100% for CK7 (25/25), 100% for p63 (25/25) and 92% for CK20 (23/25). All tumors (100%) including both MUC (13/13) and NKSCCL (12/12) were positive for p63. The majority of MUC cases (92%) stained with CK7 (12/13) with 11 of 12 demonstrating diffuse intense cytoplasmic staining; in comparison only 2/12 (17%) of NKSCCL showed focal or weakly staining with CK7. Five of 13 (38%) MUC and none of the 12 (0%) NKSCCL were positive for CK20. Diffuse strongly cytoplasmic staining with CK7 and/or positive CK20 staining favors the diagnosis of MUC over NKSCCL (p< 0.01).
Conclusions: ICC performed on cell-transferred cytologic specimen is very accurate with a high concordance rate comparable to the results obtained on the formalin-fixed tissue. A panel of CK7, CK20 and p63 performed on the cell-transferred smears is useful for the FNA diagnosis of metastatic urothelial carcinoma especially in cases lacking an adequate cell block. P63 is a sensitive marker that is positive in both urothelial and squamous carcinoma. In the appropriate clinical setting, the findings of intense CK7 staining and/or positive CK20 coexpressed with p63 is diagnostic of a metastatic urothelial carcinoma.
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 80, Wednesday Afternoon