[Synchronic multicentric osteosarcoma. A case in a 10 year old boy and review of the literature].

The osteosarcoma is a malignant neoplasm originating in bone-producing cells whose usual presentation is predominantly monostotic in long bones. The polyostotic expression is rare, variable and controversial, predominantly high-grade cellular lesions in children; low-grade lesions that affect long bones in adults and others that show a dominant lesion in long bones from which metastases arise. We present the case of a ten-year-old patient with painful tumors in metaphasis and diaphysis of the femur, tibia, fibula, clavicle, humerus, as well as in pelvis, vertebrae and base of the skull of synchronous appearance with blindness. Diagnosis was made through X-ray images, CT scan, magnetic resonance imaging (MRI), and incisional biopsy of the femur. Evidenced of absence of neoplastic manifestation in lung imaging, at the time of pathological diagnosis. Histological findings revealed a high-grade osteosarcoma.