A young man of 29 years presented to the Emergency Room reporting worsening dyspnea for about 2 weeks. He had never had previous cardiovascular disease nor had risk factors for them.
Hemodynamics were stable, but arterial blood gases showed hypocapnic hypoxia.
The ECG revealed a S1Q3T3 pattern, incomplete right bundle branch block and signs of right ventricular overload.
D-dimer was 4493 ng/ml. CT pulmonary angiogram (CTPA) showed massive bilateral embolism with thrombotic material in the right ventricle (RV) and almost complete obliteration of pulmonary trunk and main pulmonary arteries; moreover, there were subpleural nodularities in upper pulmonary lobes.
Echocardiogram showed a dilated and hypokinetic RV, moderate tricuspid regurgitation with a sPAP of 80 mmHg, thrombotic pulmonary trunk obliteration and floating thrombi adhered to the tricuspid valve.
UFH therapy was started.
After ten days, there was no improvement in clinical status, echocardiography and CTPA. So, we decided to perform mechanical thrombectomy.
In addition to thrombotic material, fibrous tissue was extracted and histologically analyzed.
At the end of the procedure, the patient became hemodynamically unstable (BP 80/40 mmHg and HR 130 bpm) with dyspnea and tachypnea. ABG showed mixed acidosis. Right ventricular function worsened due to high afterload for the persistence of thrombotic material in the pulmonary trunk, defining a picture of obstructive shock. We started fibrinolysis (with rtPA), enoximone and norepinephrine, but asystole occurred and the patient eventually died.
The histological examination revealed that the mass was a pleomorphic rhabdomyosarcoma of the pulmonary artery.
Primary pulmonary artery sarcoma is an extremely rare and histologically heterogeneous disease.
It develops mainly from great pulmonary arteries and then it grows up in the lumen of vessels. It may involve pulmonary valve and RV and invade pulmonary parenchyma and loco-regional lymph nodes.
Diagnosis is challenging, because it simulates pulmonary embolism in clinical, echocardiographic and radiological presentation.
Suspicion may arise from lack of benefit from anticoagulant therapy. Nodular pulmonary infiltrates are typical.
There are two surgical approaches: pneumectomy or endarterectomy (as palliation).
Prognosis is poor: mean survival of 1,5 month without therapy and 10 months with pneumectomy.
In addition to the progression of the disease, death can occur for obstructive shock, as in our patient.