Primary Intimal Sarcoma with Chondrosarcoma Differentiation of the Pulmonary Artery

We report a rare case and our experience of successfully treating intimal sarcoma (IS) with chondrosarcoma differentiation arising in the pulmonary artery. A 36-year-old man presented with a thrombosis-like mass in the pulmonary trunk. Anticoagulant therapy was initiated, but his clinical condition worsened despite adequate anticoagulation. Positron-emission tomography/computed tomography (CT) revealed a neoplastic lesion. The patient underwent endarterectomy and tumor resection. Microscopically, marked cartilaginous differentiation of the cancer cells admixed with pleomorphic, spindle, and round cells was noted. They were immunoreactive for S-100 protein and isocitrate dehydrogenase 1, focal and weak for desmin and murine double minute-2, but negative for ERG, CD34, and myogenin. A diagnosis of IS with chondrosarcoma differentiation was made. The patient received six cycles of adjuvant chemotherapy, and a follow-up chest CT did not show evidence of recurrence.