Cytologic diagnosis of low‐grade papillary urothelial neoplasms (low malignant potential and low‐grade carcinoma) in the context of the 1998 WHO/ISUP classification

Abstract

The 1998 World Health Organization/International Society of Urological Pathology (WHO/ISUP) classification of urothelial neoplasms introduced a category called papillary neoplasm of low malignant potential (LMP) and separated it from low-grade papillary urothelial carcinoma (LGPUC), which was thought to yield abnormal cells in cytology specimens. The objective of our study was to evaluate the effectiveness of urine cytology in diagnosing these lesions. Eighty-six paired transurethral surgical biopsy and corresponding urine cytology specimens representing the spectrum of urothelial papillary lesions were examined. Consensus diagnosis on each biopsy was made, and the distribution was as follows: 16 benign urothelium, 27 LMP, 28 LGPUC, and 15 high-grade papillary urothelial carcinoma (HGPUC). This was followed by a blinded independent review of the urine cytology specimens by three observers. Each cytology case was marked as negative, atypical, suspicious, or positive for malignant cells by using previously published cytologic criteria. When the negative and atypical diagnoses were grouped together as "benign" and the suspicious and malignant diagnoses as "malignant," the detection rate of "malignancy" of the lesions was as follows: LMP, 37%; LGPUC, 25%; and HGPUC, 53%. The false positive rate was 6%, and the positive predictive value (PPV) was 94%. Detection rates of cells that were at least "atypical" were as follows: LMP, 74%; LGPUC, 79%; and HGPUC, 100%. While most of the LMP and LGPUC cases yielded cells that were at least "atypical," there was no significant difference in the distribution of cytologic diagnoses for LMP and LGPUC cases (P > 0.05). Urine cytology in the context of the 1998 WHO/ISUP classification appears to be useful as a screening tool but does not appear to discriminate LMP effectively from LGPUC.

Is Conventional Urinary Cytology Still Reliable for Diagnosis of Primary Bladder Carcinoma? Accuracy Based on Data Linkage of a Consecutive Clinical Series and Cancer Registry

“…The finding of a (overall) low sensitivity might be compensated by the fact that a higher sensitivity is observed for high-grade tumors, which confirms other similar observations where sensitivity ranges between 25 and 57% or 53 and 92% for low- and high-grade tumors, respectively [1,2,7,9,10]. This might be regarded as a favorable aspect, since G3 tumors are more likely to be aggressive and life threatening, whereas G1 and G2 tumors are more likely to be slow growing and potentially over-diagnosed, particularly in older subjects.…”

“…Deshpande and McKee [11] had similar results, with sensitivity increasing from 31.0 to 56.6% and specificity decreasing from 96.6 to 90.1% when C3 reports were assumed as positive instead of negative. Similarly, Whisnant et al [9] reported a sensitivity improvement from 25 to 79% or from 53 to 100% for low- and high-grade tumors, respectively, when an atypia (C3) report was assumed as positive.…”

“…The performance of cytology has been criticized due to its low sensitivity with substantial variability (in the range of 23.0–75.0%) [1,2,3,4,5,6,7,8]. Sensitivity is known to be lower for low-grade tumors than for high-grade ones [1,2,6,7,9,10]. Urine cytology has thus been proposed for combination use with, and not as an alternative to, cystoscopy [5].…”

Clinical Value of Dividing False Positive Urine Cytology Findings into Three Categories: Atypical, Indeterminate, and Suspicious of Malignancy

“…Several reports have shown that assuming class III reports to be positive instead of negative improves sensitivity while maintaining acceptable specificity. (Whisnant et al, 2003;Deshpande et al, 2005;Turco et al, 2011) Although the design of the current study did not allow us to draw a similar conclusion from our data, our findings support this notion, at least for the category of suspicious of malignancy.…”

Quantitative evaluation of telomerase subunits in urine as biomarkers for noninvasive detection of bladder cancer

“…Although the diagnostic yield of cytology is expected to increase in the context of the new WHO classification, 40 data on this issue have been controversial. 41,42 Moreover, it remains to be seen whether the revised histopathologic classification of urothelial tumors, though designed for better discrimination between the biologic potentials of bladder neoplasms, will lead to changes in the management of bladder cancer patients. 38,38,43 This issue is discussed controversially, 39,40,44,45 and the clinical significance of identifying lesions of low malignant potential remains to be established.…”