A case of an adamantinoma of the tibia and fibula is described in a 10-year-old girl who died after 17 years with pulmonary metastasis. For a long time, an exact diagnosis couldn't be made. Histologically the lesion was called chronic osteomyelitis (Brodie's abscess), synovial sarcoma and spindle cell sarcoma. The revision of the histological sections revealed a fibrous dysplasia-like pattern in the first lesion of the tibia with tiny foci of an epitheloid-like pattern. This had could be the key to the right diagnosis, because sometimes adamantinoma of long bones is associated with a fibrous dysplasia-like pattern. The reason for misinterpretation of the histological features is seen in the typical variable histological pattern of this tumor (basaloids, squamoid, spindled and tubular pattern). In this connection is refered to the necessity to correlate the histological feature with the X-ray in making diagnosis in bone pathology.