Hypertrophic pulmonary osteoarthropathy diagnosed by FDG PET-CT in a patient with lung adenocarcinoma.

A 52-year-old man had a positron emission tomography computed tomography (PET-CT) scan for staging of a biopsy proven lung adenocarcinoma. An additional acquisition of the lower extremities was performed as the patient complained of bilateral leg pain. The PET-CT scan showed a 6.5 x 5.0 cm left upper lobe lung mass invading the mediastinum with maximal standardized uptake value of 10.7, compatible with primary lung cancer. The CT portion of the PET-CT of the legs showed extensive irregular bilateral periosteal new bone formation in the long bones. The PET images showed diffuse moderately increased FDG uptake in the periostea of the long bones of the legs, with some focal sites of more intense FDG uptake in the thicker portions of the periosteum. A bone scan showed mild hyperemia surrounding the long bones of the legs and intense Tc-99m MDP uptake in the periostea. The patient was diagnosed with hypertrophic pulmonary osteoarthropathy.