Experts discuss the challenge of detecting CIS in bladder cancer

In this discussion, urologic oncologists Prithvi Murthy, MD, and Arpeet Shah, MD, and uropathologist Kenneth Beck, MD, discuss the challenge of identifying carcinoma in situ (CIS), highlighting why CIS is frequently overlooked and the importance of integrating clinical, cystoscopic, and pathologic findings to improve detection.

According to the experts, CIS presents unique diagnostic challenges because, unlike papillary bladder tumors, it is a flat, high-grade lesion that often lacks the obvious architectural changes seen during cystoscopy. Shah explained that CIS typically appears as subtle areas of redness, velvety texture, or other nonspecific abnormalities, and in some cases may even appear normal under white-light cystoscopy. As a result, clinicians must maintain a high index of suspicion.

The panelists also discussed why CIS is frequently underrecognized in community practice. Murthy noted that chronic bladder inflammation, bladder outlet obstruction, and lower urinary tract symptoms can all produce findings that closely resemble CIS, making it difficult to distinguish benign inflammatory changes from malignancy. From the pathology perspective, Beck explained that inflammation can also complicate microscopic interpretation because reactive atypia may closely mimic neoplastic changes. In equivocal cases, pathologists may report atypia of uncertain significance, signaling the need for close clinical follow-up, treatment of any underlying inflammation, and consideration of repeat biopsy if concern persists.

The discussion concluded with practical scenarios that should heighten suspicion for occult CIS, even when cystoscopic findings appear unremarkable. Shah emphasized that patients with positive urine cytology despite the absence of a visible bladder lesion warrant thorough evaluation, including biopsy when appropriate. Persistent irritative urinary symptoms—such as urgency, frequency, and dysuria—that fail to improve despite negative urine cultures or standard therapies should also prompt further investigation. He stressed that diagnosing CIS requires synthesizing multiple clinical data points, including patient symptoms, risk factors, imaging findings, urine cytology, and treatment response, because missing this aggressive disease can have significant consequences for patient outcomes.