Ollier disease: two case reports and a review of the literature.

Ollier disease is a rare tumor with unclear clinicopathological features and pathogenesis. We herein report two cases of Ollier disease in a 15-year-old boy and a 66-year-old man. We analyzed the clinicopathological, radiographical, and histochemical characteristics of Ollier disease in these two cases. Furthermore, we reviewed the literature to better understand the clinicopathological features of this disease. The boy had multiple enchondromas in the metaphysis and upper region of the left femur, and his left leg is short naturally. The 66-year-old man had multiple enchondromas in his left ribs and lower segment of the left femur. He was sent to the hospital because of pathological fracture of the ribs. In addition, he was diagnosed with gastric cancer 4 years before visiting an orthopedic clinic. Ollier disease is a rare bone disease that often renders a typical asymmetrical distribution and is confined to the appendicular skeleton. It is known as a benign bone tumor and has a high risk of malignant transformation into a chondrosarcoma (5%-50%). Correct diagnosis requires radiographic, histochemical, and morphological analyses. Better understanding of the clinical manifestations and pathological features can improve the diagnosis and prevent malignant transformation and deformity, especially in adolescent patient.