Definition
• A sarcoma that arises in or around the main pulmonary arteries or veins
Clinical features
Epidemiology
• Very rare tumor
• Age range, 15 to 81 years
Presentation
• May be seen as a single embolus or multiple large emboli with right-sided heart failure, mimicking thromboembolic disease
• Other patients may have nonspecific symptoms including dyspnea, chest pain, and coughing
• Radiographically, a single large tumor or multiple small tumors may be seen
Prognosis and treatment
• Surgical resection with addition of postoperative chemotherapy and radiation therapy
• Poor prognosis
Pathology
Gross
• Most patients have multiple tumor emboli seen throughout both lungs; each nodule may measure less than 3 cm
• When single, a fleshy, pale-tan intravascular mass is seen that, on cut sectioning, has a multinodular firm surface
Histology
• Histological architecture varies depending on the type of sarcoma
• Undifferentiated sarcoma is most common
• Leiomyosarcoma: solid, sheetlike growth pattern of spindle cells with atypia, mitoses, and focal necrosis; positive for smooth muscle actin (SMA), negative for myogenin and MyoD1
• Rhabdomyosarcoma: may be embryonal or alveolar; positive for myogenin and MyoD1
• Fibrosarcoma: diffuse proliferation of spindle cells with areas of necrosis; only positive for vimentin
• Rarely, chondrosarcoma and osteosarcoma
Fig 1 Pulmonary artery and vein sarcoma. Pulmonary artery rhabdomyosarcoma: low power shows intravascular tumor composed of primitive cells with a sheetlike growth pattern, associated with necrosis.
Fig 2 Pulmonary artery and vein sarcoma. A, Tumor cells demonstrate round to oval nuclei with slightly irregular nuclear outline, fine chromatin, and clear to eosinophilic cytoplasm. B, Occasional tumor cells show rhabdomyoblastic differentiation with dense eosinophilic cytoplasmic inclusions and prominent nucleoli.
Fig 3 Pulmonary artery and vein sarcoma. Tumor cells are immunoreactive to myogenin (A) and desmin (B) and are negative for SMA (C). Note that the pulmonary artery wall at the top is negative for myogenin and desmin and is positive for SMA.