Usefulness of NMP22 as an adjunct to a typical urine cytology and low-grade urothelial carcinoma

The usefulness of urine cytology combined with NMP22 was evaluated for the primary diagnosis of urothelial carcinoma. Of 53 clinically suspected patients, histopathological diagnoses were low-grade urothelial carcinoma (25), high-grade urothelial carcinoma (13), and inflammatory lesions (15). Cytology was positive in 25 and negative in 14 patients. Fourteen of 25 low-grade urothelial carcinoma and 11/13 high-grade urothelial carcinoma were diagnosed correctly on urine cytology. Atypical cells seen in 14 patients were categorized as inconclusive for malignancy. The overall sensitivity of urine cytology was 65.8%, whereas specificity was 100%. NMP22 was positive in 33 patients. Of these 30, 18 low-grade and 12 high-grade lesions were true positive. Of the 20 NMP22, eight negative cases were false-negative. Ten of 15 with negative histopathology were also negative for NMP22, three were false-positive, and two showed erratic results. Nine of 14 cases with atypical urine cytology were positive for NMP22. Eight of these showed low-grade carcinoma on histopathology. The sensitivity of BladderChek NMP22 test was 79%, whereas specificity was 80%. NMP22 BladderChek test is a useful adjunct to urine cytology in atypical and low-grade carcinoma. Diagn. Cytopathol. 2010;38:788-790.