Pulmonary artery sarcomas (PAS) are rare malignant tumor,
poorly differentiated,
which originate in most cases by the totipotent intimal stem cells of the pulmonary trunk,
and for this reason is referred to as "intimal sarcoma"; in the literature about 250 cases have been described [1,2].
Histopatology
The intimal PASs usually are malignant mesenchymal tumors,
poorly differentiated,
with fibroblastic or miofibroblastic differentiation.
In some cases may present specific histological patterns and be classified in osteosarcomas,
rhabdomyosarcomas and angiosarcomas (most frequently).
The pulmonary artery leiomyosarcomas are instead sarcomas arising from the “tunica media” of the vessel and are called "wall sarcomas" [3].
The distinction of different tumors is based exclusively on histological findings.
Clinical findings
PASs occur in middle age,
with no specific clinical features,
which may mimic other diseases such as lung cancer,
mediastinal masses,
and especially acute or chronic pulmonary embolism.
They have a poor prognosis,
so early and proper diagnosis is necessary to set the appropriate therapy.
Symptoms include chest pain,
cough,
dyspnea,
hemoptysis,
pulmonary hypertension and right heart failure [4,5].
Often there are also systemic manifestations such as fever,
anemia,
night sweats and weight loss that are indicators of malignancy.
The absence of predisposing factors for pulmonary embolism (no venous thrombosis of lower limb with echo-color-doppler,
no finding suggestive of hypercoagulable state) and the progressive worsening of dyspnea in patients with intraluminal filling defect despite anticoagulation therapy are factors suggesting for PAS.
Therapy and prognosis
PAS have a poor prognosis.
Surgical resection remains the therapy of choice,
preferably carried out with radical intent.
However despite the surgical therapy,
the average survival time is approximately 12 months [3].
In case of tumors that determine occlusion of the arterial branches with main significant hemodynamic changes,
palliative surgery to relieve symptoms can be helpful.
The average survival to 5 years in patients with PAS is less than 6%.
Death is usually due to right heart failure by obstruction of the pulmonary arteries [6].
For these reasons,
a correct early diagnosis is of fundamental importance and the radiologist is usually the first that can put the suspicion of PAS in patients with severe dyspnea and filling defect in the pulmonary artery.