Pulmonary artery constriction by mediastinal lymphoma simulating pulmonary embolus

Area of Science:

• Cardiology
• Oncology
• Radiology

Background:

• Mediastinal lymphoma is a rare cause of pulmonary artery (PA) constriction.
• Pulmonary embolism (PE) is a common differential diagnosis for patients presenting with symptoms of acute cardiopulmonary compromise.

Observation:

• Two patients with mediastinal lymphoma presented with clinical symptoms suggestive of PE.
• Radionuclide lung scans revealed abnormal perfusion in the right lung for both patients.

Findings:

• Pulmonary angiography demonstrated diffuse concentric narrowing of the right main PA in both cases.
• One patient had severe encasement of the right PA by a lymphomatous mass, confirmed at autopsy.
• The findings highlight the role of PA constriction secondary to lymphoma.

Implications:

• Pulmonary angiography is essential for accurate diagnosis in cases of suspected PE with abnormal perfusion scans.
• Early recognition of lymphoma-induced PA constriction can guide appropriate treatment strategies.
• This case series emphasizes the importance of considering extrathoracic compression in the differential diagnosis of PA abnormalities.