Intimal Sarcoma in the Pulmonary Artery in a Young Individual: A Case Report and Review of Prior Cases

Intimal sarcoma is a rare neoplasm that is highly malignant with less than one-year survival and without distinctive etiology arising in large blood vessels. Most of the time, cases involve the aorta and rarely the pulmonary artery. The mean age of the affected patients is 48 years for pulmonary artery and 62 years of aortic intimal sarcoma. The first reported case of intimal sarcoma was described in 1923, and until now, about 300 cases have been reported worldwide. Patient with this disorder most often present dyspnea on exertion and chest pain. The tumor pathological findings are spindle cells with fascicular and storiform pattern with necrosis and myxoid changes. Cytogenetically, most cases have amplification of the 12q12-15 containing CDK4, TSPAN31, MDM2 genes. We report a case of pulmonary artery intimal sarcoma in a 29-year-old man who presented with sudden onset of chest pain, shortness of breath and history of weight loss. Radiologic finding shows pulmonary embolism, multiple pulmonary nodules with cavitation. Pulmonary endarterectomy was performed. Grossly the pulmonary artery shows a mass attached to the vessel wall, partially occluding the lumen. Histologically it shows atypical pleomorphic cells, which are ovoid to spindly with high nuclear to cytoplasmic ratio, abundant mitoses and focal tumor necrosis. The immunohistochemistry study reveals the tumor cells are positive for vimentin and FLI-1. Interphase FISH results are consistent with 9% of cells showing two to four copies of chromosome 12 with three to six copies of MDM2, and 88% of cells with MDM2 amplification. The findings of our patients are consistent with intimal sarcoma of pulmonary artery. This case represents one of the youngest individuals with ntimal sarcoma in pulmonary artery