SCANNING ELECTRON MICROSCOPIC EXFOLIATIVE CYTOLOGY IN PATIENTS HAVING MALIGNANT OR NON-MALIGNANT UROTHELIAL DISEASES

Abstract

Scanning electron microscopic exfoliative cytology (SEM cytology) was performed on 147 urine specimens from 78 patients with malignant or non-malignant urothelial diseases (17 well-differentiated bladder tumors, 3 poorly-differentiated bladder tumors, 24 followed-up patients previously undergone TUR-Bt, 13 prostatic carcinomas and benign urothelial diseases). Urinary exfoliated cells could be classified into 8 types by their shapes and surface features-namely, superficial transitional cell, immature superficial transitional cell, atypical transitional cell (ATC) with pleomorphic microvilli, superficial squamous cell, immature superficial squamous cell, atypical squamous cell, smooth surfaced cell and bleb-forming cell. About 100 exfoliative cells were observed on each urine specimen, and percentages of each cell type were calculated.
Supposing that more than 3% of ATC is positive in SEM cytology, this method's specificity and sensitivity for bladder tumor were 89% and 58%, respectively. However, if its sensitivity was confined to the well-differentiated bladder tumor, its sensitivity was 71%. After the comparison of results between SEM cytology and Papanicolaou cytology (LM cytology) on urine specimens from the same patients, the sensitivity of LM cytology was high (78%) for poorly-differentiated tumor, and the sensitivity of SEM cytology was also high (77%) for well-differentiated tumor. In the followed-up cases who had formerly undergone TUR-Bt, 46.7% of patients who showed positive SEM cytology had recurrence, and on the contrary only 7.1% of those who showed negative results had recurrence. In conclusion, this study suggests that SEM cytology is superior to LM cytology in the cases of well-differentiated bladder tumor. Moreover, this may be a useful screening method for early detection of recurrent bladder tumor of well-differentiated type in followed-up cases.