But HO may precede the discovery of the neoplasm by several months. When there is no know associated disease this condition is referred as pachydermoperiostitis, a rare familial disorder. Histologically there is an inflammatory reaction with round cell infiltrates and latter the periosteal new bone formation develops. The pathogenesis of HO remains elusive. Of special interest is the regression of the new periosteal bone which frequently occurs after removal of a lung carcinoma.
Associated synovitis can lead to increased radionuclide uptake in the periarticular region.
Of note, none of these 48 patients had increased spinal uptake. A patchy uptake in the long bones is not unusual. These scintigraphic findings frequently appear before roentgenographic findings, correspond well with clinical manifestation and decreased after treatment. Resnick, et al. Rosenthal, et al.