Vomiting in an infant with congenital nephrotic syndrome: Questions and Answers

Most patients with congenital nephrotic syndrome (CNS) exhibit a failure to thrive. A previous study reported that five of 41 (12 %) infants with CNS had hypertrophic pyloric stenosis (HPS) requiring surgery. The reason for this is undetermined, and there are few reports regarding the relationship between these conditions or their clinical course. We present the case of a 4-month-old girl with CNS. She did not show typical manifestations of HPS, but thickened mucosal and submucosal layers and hypertrophy of the pyloric muscle were detected by repeated ultrasound examinations prior to the diagnosis of HPS. Pyloroplasty was performed to improve her poor weight gain and led to ideal growth. Our case indicates that obstruction of the gastric outlet may be strongly associated with poor weight gain in patients with CNS. We should suspect involvement with HPS even if typical symptoms are lacking, and an aggressive intervention may improve poor growth. Thickened edematous mucosal and submucosal layers at the pyloric antrum have the potential to cause the high frequency of HPS in CNS.