Cytomorphologic and Immunophenotypic Profile of a Cohort of Small Cell Carcinoma of the Urinary Bladder

Abstract

Background: The incidence of primary small cell carcinoma (SCC) of the urinary bladder is extremely rare. We sought to analyze the cytologic and immunophenotypic features of SCC of the urinary bladder in urine and reassert the importance of cytologic examination of urine specimens for diagnosis of this tumor. Methods: We studied the clinical and cytomorphologic features in the presurgical urine specimens (4 voided urine and 2 bladder-washing specimens) of histopathologically and immunohistochemically proven cases of SCC of the urinary bladder. Results: There were 6 cases, all males, with an age range of 61-81 years. On cytologic and histopathologic examination, typical SCC morphology was present in all cases. On immunohistochemistry, synaptophysin and CD56 were positive in all 6 cases, while chromogranin was positive in only 3. The Ki-67 labeling index ranged from 30 to 100%. Conclusions: SCC should be kept in the differential diagnosis, when high-grade urothelial carcinoma is suspected in a urine cytology specimen, as this distinction has important therapeutic and prognostic implications. Therefore, a careful observation and, if required, the use of an appropriate immunocytochemical panel on the presurgical urine specimens can lead to a correct diagnosis.

Small cell carcinoma of the bladder with coexisting prostate adenocarcinoma: two cases report and literature review

“…According to pre-operative serum chemistries, both patients had higher PSA level than normal (4 ng/ml). Macroscopically, SCCB is usually round or oval without pedicles, and infiltrates into the bladder wall [ 13 ]. It is difficult to diagnose SCCB by clinical manifestation or imaging examination.…”

The value of intercluster single cell streaks, triplet signet ring cells, and a two‐cell population in urine small cell neuroendocrine carcinoma

“…Small cell neuroendocrine carcinomas (SCNEC) of the urinary bladder are rare 1‐5 . They can be primary urinary bladder tumours, or secondary due to distant metastases or extension from adjacent organs.…”

“…They can be primary urinary bladder tumours, or secondary due to distant metastases or extension from adjacent organs. Primary bladder tumours can be pure forms or mixed components of high‐grade urothelial carcinomas (UC) 3 . They have similar clinical and radiologic features to UC.…”

“…They have similar clinical and radiologic features to UC. Urine cytology could be the first encounter 1‐6 . Correct cytological recognition and distinction from other lesions are important because management is different 1 .…”

“…Karyorrhexis, necroinflammatory debris, and naked nuclei are common 1,5 . Nuclear moulding, rosettes, smearing, and crush artifacts may be absent or occasionally present in urine samples, but not as prominent as in fine needle aspiration samples 1,3 . Scarcity and degeneration are more likely in urine samples 2 .…”