Challenges in diagnosing vaginal mass in a pregnant woman with an underlying duplex collecting system disease: a case report

Congenital renal anomalies are a sequence of defective renal parenchymal or collecting system development and migration that may be discovered during the prenatal period or incidentally among adults. Duplex collecting system diagnosing in adults represents a challenge to physicians. Long-term history of urinary tract infections besides vaginal mass in pregnant women should raise the suspicion of underlying urinary tract malformation. CASE PRESENTATION: In this case, a 23-year-old pregnant woman at 32 weeks came to the clinic for a routine check-up. A vaginal mass had been noticed during the examination and was punctured, revealing unknown fluid. Further investigations revealed left duplex collecting system consisted of an upper moiety opening with a ureterocele in the anterior wall of the vagina and a lower moiety ending with an ectopic orifice near the right ureter orifice. Therefore, the modified Lich–Gregoir procedure was done to reimplant the ureter of the upper renal moiety. Postoperative following-up investigations affirmed improvement without complications. CLINICAL DISCUSSION: The duplex collecting system disease may remain asymptomatic until adulthood or present with unexpected symptoms. The subsequent workup in the duplex kidney disease depends on the moieties’ function and the ureter orifice opening site. Although the Weigert–Meyer rule is usually used to describe the typical pattern of duplex collecting system ureters opening sites, it has many expectations in the literature. CONCLUSION: This case shows how some common symptoms may lead to finding an unexpected urinary tract abnormality.