Hypertrophic pulmonary osteoarthropathy with positive antinuclear antibodies: case report

A male Afro-descendant patient, 57 years old, complaining of polyarticular involvement and weight loss for 18 months, with a load of 13.5 pack years of smoking. On physical examination there was pain on palpation of the right knee and right leg, with signs of inflammation on the knee. We also observed digital clubbing in all fingers. Antinuclear antibodies (ANA) and anti-Sm antibodies were positive. X-rays of the legs and arm showed cortical thickening of long bones. The computed tomography demonstrated a large mass located in the middle lobe of the right lung. The anatomopathological study revealed a bronchial adenocarcinoma. The history of polyarticular involvement associated with positive anti-Sm and ANA antibodies could lead to an erroneous diagnosis of systemic lupus erythematosus. Considering the bad consequences of delayed diagnosis in this patient, the medical team should be alerted for suspecting and look for a lung cancer under these circumstances.