Late-Presenting Congenital Diaphragmatic Hernia Initially Diagnosed as a Splenule on CT Imaging

Congenital diaphragmatic hernia (CDH) is a rare defect that most commonly presents in neonates with severe respiratory distress. Late presentation in older children is exceedingly rare and often accompanied by nonspecific symptoms, leading to diagnostic challenges. We report the case of a 9-year-old child who initially presented with nonspecific abdominal pain, nausea, and vomiting. Initial evaluations, including computed tomography (CT) imaging, led to the initial diagnosis of a splenule. Owing to persistent symptoms, repeated imaging 2 weeks later revealed herniation of abdominal contents into the thoracic cavity, confirming a large left-sided CDH. The patient underwent thoracoscopic surgical repair of a Bochdalek defect, leading to resolution of symptoms. This case highlights diagnostic challenges surrounding late-presenting CDH, including its variable clinical presentation ranging from nonspecific gastrointestinal or respiratory symptoms, as well as challenges of radiographic interpretation. This case emphasizes the importance of considering CDH in diagnostic workups in all age groups, even when imaging findings are inconclusive, to ensure timely and accurate diagnosis and treatment.