Primary extraskeletal chondroblastic osteosarcoma of the pericardium: a case report and literature review

BACKGROUND: Primary extraskeletal chondroblastic osteosarcoma has very poor prognosis, especially in the elderly. The pericardium is an extremely rare site for this tumour. CASE SUMMARY: A 67-year-old man presented with a large pericardial effusion and an intrapericardial mass. His past medical history of pulmonary tuberculosis led us to initially suspect tuberculous pericarditis. Primary extraskeletal chondroblastic osteosarcoma arising from the pericardium was diagnosed by the pathologist after surgery. The patient suffered severe intraoperative blood loss and surgical trauma. He went into shock and died a few hours after surgery. DISCUSSION: Extraskeletal chondroblastic osteosarcoma is a very rare tumour with a grim prognosis. Clinical manifestations frequently are not specific and can be explained by associated pathology. In this report, we describe an unusual case of primary extraskeletal chondroblastic osteosarcoma located in the pericardium and present a review of the literature.