Pulmonary Angiosarcoma

Primary pulmonary artery sarcoma is a rare tumor.

The diagnosis is often delayed due to the nonspecific symptoms, mimicking pulmonary embolism, as well as its relatively slow growth.

The presentation depends on the degree of pulmonary artery obstruction.

The sarcoma may involve the main pulmonary trunk, and may extend into both of the main pulmonary arteries. These patients may have evidence of severe right heart failure.

Signs and symptoms include hemoptysis, dyspnea, chest pain, cough, night sweats, edema, cyanosis and syncope.clinic clinic clinic make all the diag

These symptoms may be present for over a period of one year.

Because of the duration of symptoms, difficulty in diagnosis, and psychiatric depression may result.

Clinical diagnosis is difficult in this disease, and most diagnoses are made post-mortem.

The differential diagnoses include pulmonary thromboembolism, congenital narrowing of the pulmonary vessels, fibrosing mediastinitis, pulmonary arteritis, myogenic sarcoma, malignant fibrous histiocytoma, and carcinosarcoma.

Pulmonary angiosarcoma often presents with a clinical and radiographic picture compatible with pulmonary embolism.

Clinical examination may reveal systolic murmur in the pulmonary area and acute right ventricular hypertrophy or failure.

Chest radiographs may demonstrate one or all of the following signs of pulmonary sarcoma: hilar enlargement, peripheral parenchymal infiltrates, decreased pulmonary vascular markings, enlargement of the central pulmonary artery, and solitary or multiple lung nodules.

CT scans may detect a soft tissue density located in or around the pulmonary arteries.

Differentiating thrombus from sarcoma is difficult, unless there is evidence of tumor elsewhere.

Head, chest and abdominal CT should be obtained to rule-out distant metastases.

Bronchoscopy and biopsies are usually nondiagnostic, but may be helpful. Ventilation/perfusion scans demonstrate perfusion defects of varying degree in one or both lungs.

The perfusion defects are indistinguishable from pulmonary embolism. Serial scans show no resolution despite anticoagulation, signaling another cause.

Pulmonary angiograms are useful to confirm occlusion of the pulmonary arteries and to delineate the size and location of the lesion.

Angiography can also be used to obtain a histological diagnosis by an endocardial biopsy.

Two-dimensional echocardiography is used to locate the mass and to detect abnormal tricuspid function and/or dilation of the right atrium and ventricle.

Initially patients are often treated with anticoagulants because of the misdiagnosis of pulmonary embolism. An alternative diagnosis from pulmonary embolism should be suggested by the following:

(1) occurring in patients with no predisposing factors for embolism,

(2) inadequate relief of symptoms with anticoagulant therapy, and

(3) distinctly abnormal perfusion studies.

These observations should suggest another cause of the pulmonary arterial obstruction.

Electron microscopy assists in the identification of angiosarcomas by the hyperchromatic spindle cells, histiocytes, and pleomorphic cells with giant multinucleated cells present

The spindle cells typically have abundant cytoplasm and centrally located nuclei.

The giant multinucleated cells demonstrate abundant eosinophilic cytoplasm, characteristic of myogenic differentiation. Mitoses and central necrosis are commonly found.

The tumors are thought to be derived from mesenchymal cells of the bulbus cordis.

There are various degrees of differentiation that range from undifferentiated to well-differentiated. Well-differentiated tumors may contain fibrous tissue, cartilage, muscle, and bone.

With surgical examination, the pulmonary artery may be nonpulsative, firm and noncompressible.

The intrapericardium must be explored to evaluate the proximal extent of the tumor.

If lung resection is an option, the main bronchus and superior and inferior pulmonary veins are transected.

The pulmonary artery is transected at a point proximal to the origin of the tumor.

Cardiopulmonary bypass may be necessary to gain control of the proximal pulmonary artery.

Treatments are surgical excision, chemotherapy and/or radiotherapy, however the prognosis is extremely poor.

The mean survival after the onset of symptoms is one year (1).

Patients receiving chemotherapy and radiotherapy alone have a poorer prognosis.

Long term survivors have typically been treated with surgical excision, with or without additional therapy