Superior vena cava syndrome induced by lung hyperinflation in chronic obstructive pulmonary disease: a case report

BACKGROUND: Superior vena cava syndrome is rarely attributed to chronic obstructive pulmonary disease. CASE PRESENTATION: We present the case of an 82-year-old Japanese man who experienced gradually progressive dyspnea on exertion. His physical examination revealed small vascular dilatations on his chest and upper abdominal skin characterized by blood flow from head to leg, indicating superior vena cava syndrome. Radiographic findings included lung hyperinflation with a drop-like heart on chest X-ray, and emphysematous changes on computed tomography. The superior vena cava appeared extremely narrow and slit-like, with no adjacent mass or giant bulla. Pulmonary function testing indicated a forced expiratory volume in 1 second of 0.82L (44.4% of predicted value) and a forced expiratory volume in 1 second/forced vital capacity of 31.29%. A diagnosis of chronic obstructive pulmonary disease was made. We discuss how longitudinal forces can narrow the superior vena cava, particularly when it protrudes toward the lung field due to its anatomical location in the upper mediastinum. The absence of mediastinal adipose tissue may render the superior vena cava susceptible to compression, resulting in a loss of its typical columnar structure. The protrusion of the superior vena cava toward the lung field may be a contributing factor to superior vena cava narrowing in chronic obstructive pulmonary disease. CONCLUSION: This case represents the first reported instance of superior vena cava syndrome associated with chronic obstructive pulmonary disease, characterized by lung hyperinflation, in the absence of a giant bulla.