A Contemporary Clinicopathologic Analysis of Primary Urothelial Carcinoma of the Urethra Without Concurrent Renal Pelvic, Ureteral, or Bladder Carcinoma

Abstract

Primary urothelial carcinoma (UCa) of the urethra is relatively uncommon, and the underlying pathogenesis has not been well characterized, especially in the absence of concurrent UCa at other sites. A search for cases of primary UCa of the urethra was conducted. Patients with concurrent UCa of the renal pelvis, ureter, or bladder at the time of diagnosis of the primary tumor were excluded. Clinicopathologic and follow-up data were obtained. A total of 35 cases from 30 patients (27 male and 3 female) were included in the study. The mean patient age at the initial diagnosis was 71 years (range: 41-90 years). Cases were composed of high-grade UCa (26 of 35 = 74%), low-grade UCa (4 of 35 = 11%), and UCa in situ (5 of 35 = 14%). Invasion was present in 14 of 26 (54%) cases of high-grade UCa. Interestingly, 23 of 30 (77%) patients had a previous history of UCa including 7 (30%) cases with divergent differentiation or variant histology. Follow-up data were available in 23 patients with a mean duration of 26.7 months (range: 0.6-87 months). Eleven patients (31%) died of metastatic UCa. This is one of the largest studies to date of primary UCa of the urethra without concurrent UCa of the renal pelvis, ureter, or bladder. Previous history of UCa of the bladder, especially with divergent differentiation or variant histology is conceivably a key risk factor for developing subsequent primary UCa of the urethra. These findings are important for the development of surveillance protocols and therapeutic strategies.