Abstract
Two cases of bizarre parosteal Osteochondromatous proliferation (BPOP) were treated with EHDP (ethane-1, hydroxy-1, 1-diphosphonic acid), after local resection of the lesion based on the hypothesis that BPOP is a form of heterotopic ossification. In one case in which the lesion affected the humerus, the tumor recurred one month after the operation, possibly due to a delay of treatment and the short duration of drug administration. In the other case, which was a rerecurrent lesion affecting the middle phalanx, no evidence of recurrence was noted two years after the last surgery. This patient was treated with EHDP for three months. The difference in outcome between these two cases may have been due to the difference in the duration of EHDP treatment. However, the size of this small clinical trial precludes the formation of the firm conclusion that EHDP is effective in preventing local recurrence of BPOP.
