Primary Osteosarcoma of the Heart: Experience of an Unusual Case
A 23-year-old man was referred to our clinic because of chest pain, cough and hemoptysis. His physical examination and chest X-ray revealed left pleural effusion. Thoracentesis was performed and exudative aspiration fluid cytology did not show atypical or malignant cells. Routine laboratory tests were normal except a mild increase in lactate dehydrogenase. Echocardiography (echo) revealed a left atrial mass measuring 3.8 × 3.8 cm in diameter, filling the left atrial cavity and extending into the mitral valve during diastole, causing severe mitral stenosis symptomatology (fig. ). The presumptive diagnosis was a cardiac myxoma; because of the symptoms it had caused, tumor excision with mitral valve replacement was performed. Pathological examination revealed a high-grade conventional osteosarcoma arising from the cardiac wall. The tumor cells were mostly osteoblastic in nature. The lace-like pattern of the osteoid matrix was seen between these atypical osteoblasts. S-100 immunostain was negative and vimentin was positive. S-100 negativity excluded the possibility of a malignant nerve sheath tumor with extensive tumoral bone production (fig. , fig. ).\nDue to the possibility of a further primary tumor or distant metastasis, a bone scan and computed tomography (CT) were performed; the bone scan was normal, and the thoracic-abdominal CT scan did not show any signs of distant metastasis or another primary tumor. Adjuvant combination chemotherapy with cisplatin and ifosfamide (plus mesna) was done for six cycles every 3 weeks, owing to the histology and grade of the tumor. At the end of the therapy, physical examination, thoracic-abdominal CT and echo were completely normal, without a clue for recurrent disease.\n9 months after the last cycle of chemotherapy, the patient presented to our clinic with left hemiparesis and abnormal speech. A CT scan of the cranium showed a central pontine mass (3.3 × 3 × 2.5 cm) extending to the right (fig. ). The radiologists diagnosed the mass as a metastatic lesion. Neurosurgery consultation did not recommend surgery because of the close proximity to vital nervous structures. The patient was given radiotherapy with a dose of 37.8 Gy. However, during the course of hospitalization, his clinical status worsened, loss of consciousness occurred and he eventually died because the tumor compressed the vital structures at the brain stem.