Zinner 症候群:罕見無症狀精囊腫大個案報告
李宗融1、虞凱傑、林柏宏、邵翊紘、甘弘成、莊正鏗、馮思中、吳俊德、曲元正
林口長庚醫院 外科部 泌尿科；1長庚大學 醫學院 中醫學系
Zinner syndrome: A Case with An Asymptomatic Seminal Vesicle Mass
Tsung-Jung Li1, Kai-Jie Yu, Po-Hung Lin, I-Hung Shao, Hung-Cheng Kan, Cheng-Keng Chuang, See-Tong Pang, Chun-Te Wu, Yuan-Cheng Chu
Division of Urology, Department of Surgery, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan;
1School of Traditional Chinese Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
Introduction
Zinner syndrome, is a rare congenital defect with characteristics of renal dysgenesis, seminal vesicle cyst and ipsilateral ejaculatory duct obstruction, would lead to lower urinary tract symptoms, local pain, or abnormal reproductive function. In this case report, we present a patient, who went to clinic due to bilateral inguinal pain with frequent urination initially, and diagnosed with Zinner syndrome on MRI findings.
Case presentation
The 33-year-old man had experienced a small amount of inguinal pain on and off for a couple of years and hadn’t gone to the doctor until this incident. This time, he presented to clinic with a chief complaint of bilateral inguinal pain, with frequent urination, for three days. According to his statement, the pain was sudden onset, dull quality and intermittent for three days, and it was tolerable but aggravated by standing for longer periods. There were no specific precipitation factors, and the pain typically relieved by lying flat for almost ten minutes. Genital examination revealed normal, but the results of ultrasonography showed a huge lesion under bladder base. The local medical doctor referred this patient to our hospital for further managements of bladder lesion.
In our outpatient department, the patient was stable and had no symptoms including inguinal pain, micturition pain, hematuria, frequent urination, dysuria, or constipation. Besides, the urinalysis, renal-function tests and complete blood count revealed normal. The abdomen CT scan showed a solid mass at the retro-vesical region with absent right kidney. The cystoscopy showed a protruding structure at right peri-orifice area, but the urine cytology revealed normal. The MRI presented a T1 hypointense lesion in right seminal vesicle, and the cyst showed association with right ejaculatory duct obstruction. A diagnosis of Zinner syndrome was confirmed. Because his clinical conditions were stable, the doctor arranged for long-term clinic follow-up to the patient.
Discussion
Zinner syndrome is an embryologic abnormality between the 4th and 13th gestational week, and it is associated with mutation of ureteric bud and mesonephric duct. It would lead to renal dysgenesis, seminal vesicle cyst and ipsilateral ejaculatory duct obstruction. The most common symptoms are dysuria, frequent urination and perineal pain. One case report stated that seminal vesicle cyst with size smaller than 5 cm in diameter remained asymptomatic; however, our patient was still asymptomatic with a seminal vesicle cyst larger than 5.5 cm. Other than clinical symptoms, the imaging is important to diagnosis. Pelvic MRI is the gold standard to confirm the diagnosis of Zinner syndrome. Ultrasonography, Computed Tomography and cystoscopy assist doctor in planning treatment, as in our case. Management methods including aspiration of the cyst, exploration with vesiculectomy, or even robotic assisted excision of the cyst were published. Although Zinner syndrome is associated with good prognosis in most patients, some rare cases found arising malignancy in the urogenital system. In a systematic review, adenocarcinoma, squamous cell carcinoma and renal cell carcinoma were found in Zinner syndrome patients. Because the prevalence rate of malignant tumor in patients of Zinner syndrome is not clear, we consider that more cases are needed to confirm.