Congenital abnormalities may occasionally escape detection during childhood and present in adulthood. In addition, given the advances in pediatric cardiovascular surgical techniques, catheter-based interventions, and advances in medical management, pediatric patients with congenital cardiovascular abnormalities are increasing living well into adulthood and therefore may be increasingly encountered in medical practice. Among congenital cardiovascular abnormalities that may present in adulthood, partial anomalous pulmonary venous return (PAPVR) is not uncommon. Typically incidental in nature, PAPVR may occasionally result in significant pulmonary-to-systemic and left-to-right shunting, and may also be associated with other congenital cardiovascular abnormalities, rarely in the context of particular syndromes, such as the hypogenetic lung syndrome. Hypogenetic lung syndrome, also known as pulmonary venolobar syndrome and “scimitar” syndrome, is an uncommon congenital anomaly characterized by PAPVR draining into the supradiaphragmatic or infradiaphragmatic inferior vena cava, associated with a hypoplastic right lung, ipsilateral pulmonary arterial hypoplasia, dextroposition of the heart, and systemic arterial blood supply to the affected lung, typically the right lower lobe. Hypogenetic lung syndrome may present in “infantile” and “adult” forms, and may occasionally be associated with other congenital cardiovascular abnormalities and abnormalities of the lung, the former including atrial septal defects, aortic coarctation, and others; the latter include horseshoe lung, pulmonary sequestration, and abnormalities of pulmonary lobation. The PAPVR associated with the hypogenetic lung syndrome produces a left-to-right shunt that may result in pulmonary hypertension, as in the patient presented.