Lung cancer with partial anomalous pulmonary venous connection in a different lobe: a case report

Anomalous pulmonary venous connection (APVC) is a congenital malformation in which the pulmonary veins connect to the systemic venous system but not to the left atrium. APVC can be classified as total or partial (PAPVC). PAPVC is rare among surgical patients with lung cancer, and most cases are detected incidentally during surgery. We herein report a patient with lung cancer in whom PAPVC was diagnosed before surgery, which made it difficult to determine the surgical procedure.

A 71-year-old man was followed-up as an outpatient after surgery for renal cell carcinoma. Chest computed tomography showed a 22-mm nodule in the right lower lobe and PAPVC in the right upper lobe. He was diagnosed with lung adenocarcinoma (cT1cN0M0 stage IA3) and scheduled for surgery. Preoperative catheterization showed a pulmonary to systemic flow ratio (Qp/Qs) of 1.64 and mean pulmonary artery pressure (MPAP) of 16 mmHg. Surgical repair of PAPVC is indicated when a patient is symptomatic and has a Qp/Qs ≥1.5-2.0. The patient was scheduled for right lower lobectomy, but postoperative worsening of right heart strain was considered. Concomitant PAPVC repair was therefore considered, but he had no atrial septal defect and was asymptomatic; therefore, PAPVC treatment was considered unnecessary. However, we planned to perform concomitant PAPVC repair if his circulatory dynamics worsened during surgery or if his MPAP exceeded 25 mmHg. His MPAP was 20 mmHg and his circulatory dynamics remained stable, and right lower lobectomy was therefore completed. His postoperative course was favorable. Follow-up catheterization at 6 months showed a Qp/Qs of 1.19 and MPAP of 18 mmHg, with no evidence of increased right heart strain. There was no evidence of right heart failure or recurrence of lung cancer at last follow-up at 18 months after surgery.

We present a case of right lower lung cancer complicated by PAPVC in the right upper lobe. This case suggests that concomitant repair of PAPVC in the right upper lobe may not be necessary when performing right lower lobectomy, although the patient's Qp/Qs and MPAP should be considered.