下泌尿道症狀患者中意外發現的Zinner氏症候群:病例報告

蘇劭臻、許兆畬、林益聖、歐宴泉、童敏哲

童綜合醫療社團法人童綜合醫院 外科部 泌尿科

An incidental discovery of Zinner syndrome in a patient with lower urinary tract symptoms: A case report

Shao-Chen Su, Chao-Yu Hsu, Yi-Sheng Lin, Yen-Chuan Ou, Min-Che Tung

Divisions of Urology, Department of Surgery, Tungs' Taichung Metro Harbor Hospital, Taichung, Taiwan;

Introduction:

Zinner syndrome is a rare congenital anomaly of the male urogenital tract characterized by unilateral renal agenesis, ipsilateral seminal vesicle cyst, and ejaculatory duct obstruction. We report a middle-aged man incidentally diagnosed with this condition following evaluation for lower urinary tract symptoms.

Materials and Methods:

A 42-year-old man, with a history of fathering two children and previously suspected left renal atrophy, presented with a one-week history of left flank pain and dysuria. Associated lower urinary tract symptoms included urinary frequency and a sensation of incomplete emptying. He therefore came to our hospital, where genital examination was grossly unremarkable, while urinalysis revealed only mild hematuria. Renal ultrasonography demonstrated absence of the left kidney and incidentally identified a bladder lesion resembling a ureterocele (Figure 1). Subsequent CT imaging confirmed left renal agenesis with an associated seminal vesicle cyst. A tubular structure arising from the cystic lesion extended cranially, mimicking a ureter but ending blindly (Figure 2). Cystoscopy revealed a large cystic lesion occupying the left side of the bladder (Figure 3), and the left ureteral orifice was not visualized. MRI further confirmed the diagnosis of Zinner syndrome, demonstrating a seminal vesicle cyst with T1 and T2 hyperintensity, suggestive of protein-rich content (Figure 4). Uroflowmetry showed a mildly obstructive pattern (Q max 16.3 mL/s, Q avg 9.1 mL/s). The patient was managed conservatively with an alpha-blocker, with subsequent symptomatic improvement.

Discussion:

Zinner syndrome is a rare congenital malformation of the male urogenital tract, classically defined by unilateral renal agenesis, ipsilateral seminal vesicle cyst, and ejaculatory duct obstruction. It arises from abnormal Wolffian duct development and represents an important differential diagnosis of pelvic cysts in males. Most patients remain asymptomatic until the second to fourth decade of life, when symptoms such as pelvic pain, dysuria, painful ejaculation, infertility and lower urinary tract complaints may develop.

Our patient, a 42-year-old man, presented with left flank pain, dysuria, urinary frequency, and a sensation of incomplete emptying. Imaging demonstrated left renal agenesis and a seminal vesicle cyst with a blind-ending tubular structure mimicking a ureter. MRI further confirmed the cyst with protein-rich contents, thereby establishing the full diagnostic triad. Uroflowmetry showed a mildly obstructive pattern, consistent with his symptoms. However, infertility was not observed for our patient, even though a previous study reported a 24% of infertility rate.

Management of Zinner syndrome is guided by symptom severity. While surgical excision is indicated in patients with significant obstruction, pain, or infertility, conservative approaches may be appropriate when symptoms are mild.

Conclusions