[Pediatric adamantinoma. Case report].

Adamantinoma is a primary tumor of long bones, which affects mainly the shaft of the tibia, and is extremely rare in pediatrics. It frequently presents during the second decade of life, with a slight predominance in males. It is a low grade tumor, with local aggressiveness and low rate of metastasis and recurrence once it is completely removed. Its diagnosis is difficult, not only because it is a rare disease in children, but also because of the difficulty in the differential diagnosis with other benign lesions. We report the case of a 15-year-old patient with a painless swelling of the distal tibia, whose diagnosis was confirmed with the piece of amputation, as imaging features and both initial biopsies were not enough to achieve diagnosis. Though most of the literature consists of case reports, and very few in pediatric patients, they all agree on the difficulty in achieving the diagnosis of adamantinoma.