Diaphyseal Aclasis-Hereditary multiple exostoses

Radiograph of left knee AP and lateral views showing multiple bony out growth seen in the metadiaphyseal region growing away from the epiphysis in femur, tibia and fibula.

Radiograph of another patient of bilateral knee AP views showing multiple bony out growth in the metadiaphyseal region growing away from the epiphysis in femur, tibia and fibula.

Discussion: Diaphyseal Aclasis is also known as:

1. External Chondromatosis Syndrome
2. Multiple Cartilaginous Exostoses
3. Multiple Exostoses
4. Multiple Exostoses Syndrome
5. Multiple Osteochondromatosis

Diaphyseal Aclasis isa relatively rare abnormal condition that affects the skeletal system. Characterized by multiple exostoses or bony protrusions, it is inherited as a dominant trait. Approximately half of the children of an individual with diaphyseal aclasis display varying degrees of its symptoms.Evident involvement is diffuse, with the long bones usually affected more severely and more frequently than the short bones. The malignant change is more frequent compared to the solitary exostosis.

Signs of malignant development refer my other post on Chondrosarcoma in osteochondroma -

http://manju-imagingxpert.blogspot.com/2011/06/secondary-chondrosarcoma-from.html