[Unusual rheumatology cases]

A series of clinical cases very rarely observed in rheumatology is presented. These cases consist of osteoid-osteoma, osteogenesis imperfecta, pachydermo-periostosis, multiple chondromatosis, osteopecilia, Camurati-Engelmann disease. The caracteristics of the patients examined are appropriate and well adapted to the typical clinical studies of these diseases, and are considered current with the contributions concerning rheumatology appeared in the most recent literature.