Agenesis of the Left Upper Lobe of the Lung in a Young Adult Male: A Case Report.

Left upper lobe agenesis is an exceedingly rare condition, and the patients usually remain asymptomatic in their childhood. We report a case of a 19-year-old male who presented with nonspecific chest pain and shortness of breath after running. On investigation, we found that he had haziness on the left upper and mid zones and blunting of the left costophrenic angle on chest X-ray posteroanterior (PA) view. The patient had no history of pleuro-pulmonary tuberculosis or any thoracic surgery. Further workup with CT thorax and CT pulmonary angiogram (CTPA) revealed a complete absence of the left upper lobe with herniation of the right lung to the left hemithorax and absence of the left superior lobar pulmonary artery. He was managed conservatively without any complications.