BackgroundThe intricate anatomical variations in lung structure often perplex thoracic surgeons, and the accurate identification of these variations is closely associated with favorable surgical outcomes.Case presentationA 53-year-old female patient who underwent computed tomography (CT) examination due to chest discomfort, revealing the presence of a partial solid nodule highly suspected of early-stage lung cancer, measuring approximately 2.8 x 2.6 cm in the left lower lobe. Consequently, the patient underwent a single direction thoracoscopic left lower lobectomy and lymph node dissection. Intraoperatively, while attempting to dissect and free the left lower lobe vein from surrounding tissues, technical difficulties were encountered. Upon meticulous review of preoperative CT scans during surgery, an anomalous connection between the lingular vein of the left upper lobe and the left lower lobe vein was identified. Once this anatomical variation was confirmed, surgical intervention proceeded uneventfully without any significant complications.ConclusionPrecise recognition of pulmonary anatomical structures before and during surgery is paramount in recognizing rare variations such as this one as it aids in preventing potential intraoperative injuries and minimizing postoperative complications.