Congenital diaphragmatic eventration (CDE) is a rare developmental anomaly in which the diaphragmatic muscle is replaced by thin fibroelastic tissue, causing abnormal elevation of an otherwise intact hemidiaphragm. Its clinical and radiographic features overlap substantially with more common, urgent neonatal conditions such as pneumonia, sepsis, and congenital diaphragmatic hernia (CDH), making it a diagnosis that is easily missed or delayed. While left-sided disease has traditionally been considered more common, larger contemporary cohorts increasingly report right-sided predominance. We present a five-day-old term male neonate with a three-day history of respiratory distress and poor feeding, with reduced air entry and dullness to percussion over the right hemithorax. Baseline bloodwork and blood gases were unremarkable. Chest radiography revealed marked elevation of the right hemidiaphragm, broadening the differential to include CDH, congenital pulmonary airway malformation, and pulmonary sequestration. Echocardiography excluded structural cardiac disease, and abdominal ultrasound was inconclusive for diaphragmatic integrity. High-resolution computed tomography of the chest confirmed an intact, smoothly elevated right hemidiaphragm with cephalad liver displacement and right lower lobe compressive atelectasis, with no herniation of abdominal viscera, establishing a definitive diagnosis of right-sided CDE. Initial conservative management with supplemental oxygen, intravenous fluids, and antibiotics failed to improve symptoms, prompting surgical plication of the right hemidiaphragm on the ninth day of life. The postoperative course was uneventful, and the infant was discharged in stable condition. This case highlights that right-sided CDE, though historically taught as less common, is increasingly recognized in the literature and should remain an active differential in neonates with unexplained respiratory distress. A stepwise escalation to cross-sectional imaging, particularly HRCT, was essential in distinguishing CDE from its close mimics and guiding timely, effective surgical management.

Ayesha Zubair is a pediatrician affiliated with Pediatric Medicine, District Headquarters Hospital, Chiniot, and Pediatrics, Faisalabad Medical University, Pakistan. Her clinical and academic interests lie in neonatal and pediatric medicine, with a particular focus on the diagnostic evaluation of rare congenital anomalies. She has contributed to peer-reviewed case report highlighting the role of advanced imaging in accurately diagnosing uncommon neonatal conditions. She is committed to improving early recognition and management of pediatric diagnostic challenges through evidence-based clinical practice and continued academic engagement with the pediatric medical community.