The Significance of Entosis (“Bird's Eyes”) in Contemporary Urine Cytology Specimens.
Ajit S Paintal, Pamela Papas, Alejandro Contreras, Richard M Demay, Ward Reeves. University of Chicago Hospital and Medical Centers, IL; Baylor College of Medicine, Houston, TX
Background: Urine cytology is useful in screening individuals for the presence of urothelial cell abnormalities and in follow up of patients with urothelial neoplasms. The presence of entosis (“bird's eyes”) (BE) has been reported as a useful ancillary morpohologic finding which is correlated with urothelial neoplasia..
Previous reports have stated that, in the context of voided urine specimens, BE are relatively common in patients with urothelial carcinoma and relatively uncommon in patients no history of urothelial neoplasia.
Given the high frequency with which we see “bird's eyes” in urines in our practice, we were interested in exploring the relationship between BE and urothelial neoplasia.
Design: Randomly chosen cases of urinary cytology (voided urines, bladder washings, and catheterized urines) obtained between 2008 and 2010 were reviewed. All cases had histologic follow up within 6 months. Thin preps and cytospins in cases which were diagnosed as “atypical” or “suspicious” were reviewed by two pathologists under signout conditions for the presence of BE and this was correlated with histology on biopsy. In total, 69 specimens from 43 patients were evaluated. Histology on biopsy was divided into three categories: CIS/HG papillary carcinoma, LG papillary carcinoma, and benign with no history of urothelial neoplasia. In contrast to prior studies, the vast majority of our cases were bladder washes.
Results: We observed that BE were present in 20 of 29 “atypical” or “suspicious” urines (14/17 patients) with a concurrent histologic diagnosis of CIS/HG papillary carcinoma. BE were seen in 9 of 20 “atypical” or “suspicious” urines (6/14 patients) in cases of LG papillary carcinoma. Interestingly, BE were seen in 12 of 19 “atypical” or “suspicious” urines (9/12 patients) in cases with benign histology and no history of urothelial neoplasia. Of note, the majority of cases in this final group were diagnosed as “atypical” solely due to the presence of BE which ranged from focal to extensive. In contrast, in almost all “atypical” cases with BE and subsequent urothelial neoplasia, additional cytologic features of malignancy were identified. Bladder washes constituted the majority of specimens we examined.
Conclusions: BE are a common finding in the setting of urothelial neoplasia, but are not specific for malignancy in bladder wash specimens. The positive predictive value of BE as an isolated cytologic abnormality in bladder wash specimens is low.
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 68, Wednesday Afternoon