|Text in Italics is general (instructional) information|
The main complaint was pain over he ulnar side of the wrist. X rays of the wrist show bony outgrowths of both the radius and ulna in the metaphyseal region. The X ray of the tibial metaphysis shows a medial exostosis. The trabeculae of the outgrowth appear as normal bone with trabeculae in continuity with those of the parent bone. The ulna is slightly shortened.
The ulnar lesion was excised. It consisted of a bone with a thin cartilage cap. Histology confirmed an osteochondroma.
There are multiple lesions, putting this child at a high risk of malignant transformation. The risk of malignant transformation to chondrosarcoma in hereditary multiple osteochondromatosis is unknown, but may be 25-30% compared to approximately 1% for a solitary osteochondromas. Pain in an enchondroma is a reason for biopsy.
Causes of pain in an enchondroma
Forearm deformities in children
In the growing child osteochondroatosis of the forearm may cause growth deformities. The ulna tends to shorten while the radius continues and this tethering, results in bowing of the forearm. Shin (JBJS Vol 88-B, No2, Feb 2006 page 225-260) found that simple excision of the lesion was just as effective as ulnar lengthening. The only way to control future length (forearm bone) discrepancies, was to do an epipysiodesis of the radius to prevent bowing. An epiphysiodesis would be indicated if this child started developing ulnar shortening. Long term followup of all multiple osteochondroatosis cases is needed. A yearly technicium scan will show "hot" lesions and these can be considered for excision. All future symptomatic lesions will also need excision biopsy.