Clinicopathological features of pulmonary artery and vein intimal sarcomas: case series of rare pulmonary vessel intimal sarcoma

Background: Pulmonary vessel intimal sarcoma (IS) is rare. Methods: We studied gross pathology, microscopic images and immunohistochemistry of 2 pulmonary artery ISs (PAISs) and 2 pulmonary vein ISs (PVISs), followed up the prognosis, and discussed the possible causes. The clinical manifestations of IS, imaging examination, electrocardiographic examination and serological examination were also studied. Results: Grossly, the tumors were grayish yellow accompanied by local bleeding, and were manifested as sticky and slippery nodules. PAISs were located in the lumen of the pulmonary trunk or right ventricular outflow tract, and 1 of them had pedicle. PVIS was mainly located in the left atrium. Microscopically, the heteromorphic spindle cells were arranged in lobules and bundles, partially epithelioid, with visible mitotic figures. There were interstitial mucoid degeneration and local hemorrhage and necrosis/infarction. Immunohistochemistry showed that vimentin, h-caldesmon and MDM2 were all positive, SATB2 (+, 3/4); Ki67 proliferation rate was 30-60%; smooth muscle actin, desmin and CD56 were partially positive; cytokeratin and CD34 were locally positive; CD31, FLI-1, and ERG vascular markers were negative; and S-100 was negative. Case 4 showed MDM2 (12q15) amplification. Tumor markers were negative in venous blood; and lactate dehydrogenase increased in 2 cases. 3 patients died after surgery, 1 still survives after 14 months with lung and chest metastases for immunotherapy and 9 courses of chemotherapy. Conclusions: IS is rare. Microscopically, it is mainly composed of spindle cells (or local epithelioid), along with interstitial mucoid degeneration. IS can differentiate into tumor of fibroblasts, bone, cartilage and smooth muscle. The prognosis is poor.