Atypical presentation of hypertrophic pulmonary osteoarthropathy on Tc-99m MDP bone scintigraphy.

Hypertrophic pulmonary osteoarthropathy (HPOA) is a rare disease that causes periostitis and synovitis of the long bones and joints. Although the pathogenesis of HPOA is unclear, the characteristic appearance on bone scintigraphy is well known. We report a patient who underwent Tc-99m MDP bone scintigraphy for severe bilateral pain in her forearms and legs. On preliminary review of the bone scan, it appeared that the patient had multiple diffuse osseous metastases. However, more careful examination of the scan revealed an atypical presentation of HPOA.