FINALIDADE: Eeste estudo propõ-se a esclarecer as características do osteossarcoma e do sarcoma de Ewing, bem como definir o intervalo de tempo decorrido, no Brasil, entre o início dos sinais e dos sintomas e o diagnóstico definitivo, fornecendo subsídios para um diagnóstico precoce desses tumores. MÉTODO: Alguns aspectos dos diagnósticos clínicos do prontuário de 365 pacientes com menos de 30 anos de idade, portadores de osteossarcoma ou sarcoma de Ewing foram analisados de forma retrospectiva e comparativa, seguindo-se uma análise estatística. RESULTADOS: O tempo entre o início de sinais e sintomas e o diagnóstico foi de 5,25 meses no osteossarcoma e 8,1 meses no sarcoma de Ewing; o sintoma mais freqüente (89,5) nas duas neoplasias foi a dor localizada. CONCLUSÃO: O tempo para o diagnóstico de ambas as neoplasias é maior do que o observado em estatísticas norte-americanas e européias.

OBJECTIVE: The purposes of this study were to describe the early signs and symptoms of osteosarcoma and Ewing's sarcoma, identify symptoms that could be used to help differentiate the two types of tumors, and determine the time elapsed between the onset of signs and symptoms and the definitive diagnosis in our service, providing information and imputus for earlier diagnosis of these tumors. METHODS: A retrospective analysis of the medical dossiers of 365 patients under 30 years of age diagnosed with osteosarcoma or Ewing's sarcoma was performed, and the aspects of the clinical diagnosis were statistically analyzed and compared. RESULTS: The time between the onset of signs and the symptoms was 5.25 months for osteosarcoma and 8.1 months for Ewing's sarcoma, and the most frequent (89.5%) early symptom of osteosarcoma and Ewing's sarcoma was local pain. Symptoms that might aid diagnosis included early local volume increase and the presence of fever. CONCLUSION: The time until diagnosis of both neoplasias was higher than that reported for North America and Europe. Education of the lay public and medical professionals regarding suspicious early signs and symptoms might shorten the delay of diagnosis.