[A case od rare location of Ewing's sarcoma in a 6-year-old boy].

A 6 boy is described treated for two months for pneumonia. In view of absent improvement the diagnosis was verified and malignant tumour was recognized. Radiological examination and clinical observation showed presence of a tumour in the 4th rib with pulmonary metastases. Histological examination of a biopsy specimen from the rib demonstrated primary microcellular Ewing's sarcoma. Of importance are: the age of the patient, rarely described location and diagnostic difficulties in the initial stage of the disease.