Right ventricular outflow tract obstruction due to extrinsic compression by non-Hodgkin's lymphoma: importance of echocardiographic diagnosis and follow up.

Acquired right ventricular outflow tract obstruction due to extrinsic compression of the pulmonary artery is a rare manifestation of non-Hodgkin's lymphoma (NHL). We report a case of a 17 year old boy who was referred for evaluation of a large anterior mediastinal mass, causing dyspnea and cough and resulting in a harsh systolic murmur. Echocardiography demonstrated compression of the pulmonary artery by the mass, with a severe pressure gradient. Biopsy revealed intermediate grade, diffuse large cell NHL. Systemic chemotherapy rapidly led to a significant decrease in the size of the mass, and virtual disappearance of the pressure gradient. In this report, the use of echocardiography for diagnosis and follow up of extracardiac tumors is reviewed. It is suggested that this technique may also be useful for the routine staging of mediastinal lymphomas because of the potential consequences of clinically undetectable hemodynamic compromise.