Left lung cancer in a patient with congenital unilateral absence of the left pulmonary artery: a case report and literature review

BACKGROUND: Unilateral absence of pulmonary artery (UAPA) is a rare congenital disease of pulmonary circulation, which is often accompanied by other cardiovascular anomalies. Infrequently, it may remain undiagnosed until adulthood. More rarely, it is to be found with lung cancer in the ipsilateral or contralateral lung simultaneously. CASE PRESENTATION: A 56-year-old man with complaints of intermittent left chest pain for 2 months was referred to our hospital. Chest computed tomography(CT) revealed a cavitary lesion measuring 5.5 cm × 5.7 cm in the superior segment of the left lower lobe. Absence of left pulmonary artery and right-sided aortic arch were found on chest computed tomography angiography (CTA). The tumor was successfully removed via left pneumonectomy, and postoperative histopathology showed that the tumor was a squamous cell carcinoma (T2bN1). At a postoperative 24-month follow-up, the patient was free of disease and no evidence of recurrence or metastasis. Based on literature review, this is the ninth case of lung cancer in UAPA patients. CONCLUSIONS: Lung cancer and UAPA occurred ipsilaterally in 66.7% of these cases (6/9), including the present case. For those patients who occurred contralaterally, surgical treatment may be more challenging. CT and CTA could provide an accurate diagnosis for this disease entity. Identification and recognition of this rare and special disease entity may facilitate timely diagnosis and appropriate treatment.