Non-invasive papillary urothelial carcinoma of the vagina: molecular analysis of a rare case identifies clonal relationship to non-invasive urothelial carcinoma of the bladder.

We present a rare case of non-invasive papillary urothelial carcinoma of the vagina as the initial presentation of a multicentric urothelial carcinoma also involving bladder and renal pelvis and report for the first time in the literature the molecular alterations observed in the vaginal urothelial lesion and the synchronous lesions of the urinary tract. In this case, the non-invasive papillary urothelial carcinoma in the vagina displayed the same genetic alterations in the FGFR3 and PIK3CA genes as those seen in the non-invasive papillary urothelial carcinoma of the bladder contrasting with the wild phenotype observed in the invasive urothelial carcinoma of the renal pelvis. This observation could reinforce the theory of "seeding" of carcinoma cells as a valid and most likely explanation of this multifocality. In addition, we emphasize in this report the importance of recognizing this rare lesion in the female genital tract and its differential diagnosis.