Pedicelli G, Jequier S, Bowen A D, Boisvert J
Radiology. 1986 Oct;161(1):23-6. doi: 10.1148/radiology.161.1.3532180.
In nine neonates, spontaneous regression of a multicystic dysplastic kidney (MCDK) was witnessed by means of repeated ultrasound (US) examinations. In three of these patients, the diagnosis was made in utero. Follow-up examinations at the ages of 3, 5, and 32 weeks post-partum showed what would have been called unilateral agenesis of the affected side if no fetal US study had been done. In the remaining neonates, the diagnosis was made postnatally, and marked reduction in size or complete disappearance of the MCDK was observed on serial US examinations. Three neonates underwent surgical exploration. No trace of a kidney, renal artery, or ureter was found in two. A small MCDK was removed in the third patient. US reveals new features of the natural history of MCDKs. Because malignant transformation of an MCDK is rare and because US provides a means of serial assessment, the authors believe a more conservative, nonsurgical approach is appropriate and recommend an observation time of 1 year before deciding on surgical intervention, unless other problems necessitate surgical removal of the MCDK.
通过反复超声（US）检查，观察到9例新生儿多囊性发育不良肾（MCDK）出现自然消退。其中3例患者在子宫内确诊。产后3周、5周和32周的随访检查显示，如果未进行胎儿超声检查，受影响侧会被诊断为单侧肾缺如。其余新生儿在出生后确诊，系列超声检查观察到MCDK体积显著缩小或完全消失。3例新生儿接受了手术探查。其中2例未发现肾脏、肾动脉或输尿管的踪迹。第3例患者切除了一个小的MCDK。超声揭示了MCDK自然病史的新特征。由于MCDK发生恶性转化的情况罕见，且超声提供了系列评估的手段，作者认为更保守的非手术方法是合适的，并建议在决定手术干预前观察1年，除非其他问题需要手术切除MCDK。
