Pulmonary stenosis-related proteinuria misdiagnosed as nephrotic syndrome

Sir, This brief report highlights the diagnostic challenges posed by proteinuria in two children. Both cases had pulmonary stenosis (PS), which was initially misdiagnosed and managed as nephrotic syndrome due to the presence of proteinuria and generalized swelling. The first case was a 2½-year-old girl who had worsening edema over 4 months. Evaluation elsewhere revealed proteinuria, and the child was started on oral steroids and diuretics for presumed nephrotic syndrome. Despite this treatment, her edema persisted. On referral to us, she exhibited cushingoid features, hepatomegaly, ascites, and elevated jugular venous pressure. Cardiac examination revealed a prominent ejection systolic murmur. Heart sounds were audible with reduced intensity. Chest radiography showed massive cardiomegaly (cardiothoracic ratio 80%) with normal lung fields, and echocardiogram confirmed severe valvar PS with significant right ventricular (RV) dysfunction and mild pericardial effusion. Percutaneous pulmonary valve balloon dilatation (PVBD) was performed [Table 1], which resulted in immediate improvement of symptoms, including resolution of proteinuria and edema over the next few days.Table 1: Hemodynamic data obtained during pulmonary valve balloon dilatationThe second case was a 2½-year-old boy who presented with generalized body swelling over 3 months. Like the first case, based on proteinuria, he was also being treated for presumed nephrotic syndrome. Although his symptoms initially improved, the swelling worsened, and his urine protein increased to 3+. At the presentation to our institution, the boy had hepatomegaly, ascites, cushingoid features, and a systolic thrill in the pulmonary area. An echocardiogram revealed severe valvar PS with significant RV dysfunction. Following urgent PVBD [Table 1], his heart failure and proteinuria resolved promptly, and the steroid treatment was tapered off over 2 weeks. Severe PS leads to RV hypertrophy and eventual RV systolic dysfunction. Heart failure can manifest with proteinuria due to altered glomerular hemodynamics,[1] thus mimicking nephrotic syndrome, where significant proteinuria is the hallmark. Both cases illustrate that proteinuria and generalized edema can be misleading, often attributed to nephrotic syndrome when they might actually be due to heart failure secondary to PS or other cardiac ailments.[2,3] This diagnostic challenge underscores the need for careful clinical evaluation, including cardiac auscultation and echocardiography, to differentiate between these conditions. Features such as a prominent ejection systolic murmur, an audible or inaudible pulmonary component of the second heart sound, and cardiomegaly provide clues toward cardiac involvement. Echocardiography easily confirms the diagnosis and guides appropriate treatment. The report highlights several key points: Importance of accurate diagnosis: Proteinuria in the setting of generalized edema is not exclusively indicative of nephrotic syndrome. It can result from heart failure, particularly in the context of severe PS. Accurate diagnosis is crucial to avoid inappropriate treatments Role of clinical examination: With technological advancements, the emphasis on physical examination may diminish, yet it remains vital. Proper clinical examination, including detailed cardiac auscultation, can reveal important clues that should guide further diagnostic testing Diagnostic challenges: Both cases demonstrate the pitfalls of a “treat and evaluate” approach, where initial treatment based on an assumed diagnosis can lead to delays in correct diagnosis and management. This approach can be particularly problematic in cases where symptoms overlap between different conditions Management and treatment: For children with PS, timely intervention with PVBD can lead to rapid resolution of heart failure symptoms and proteinuria. This treatment addresses the root cause of the problem and can prevent unnecessary and potentially harmful treatments. In summary, the report underscores the necessity of comprehensive evaluation in pediatric cases presenting with proteinuria and generalized edema. Differentiating between nephrotic syndrome and heart failure-related proteinuria requires a combination of clinical skills and diagnostic tools.[4,5] The resolution of symptoms following appropriate treatment in these cases highlights the importance of careful assessment and accurate diagnosis to ensure effective management. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.