An Unusual Mimicker of Systemic Lupus Erythematosus: A Case Report.

We present a case of a 47 year-old African American female with 15 pack-years of tobacco use and heavy alcohol use who presented with arthritis and was found to have a positive antinuclear antibodies (ANA), anti double stranded DNA antibodies (anti-dsDNA), and anti-Sjogren's syndrome-related antigen A and antigen B (anti-SSA and anti-SSB). She was subsequently found to have a lung adenocarcinoma associated with hypertrophic pulmonary osteoarthropathy (HPO). This demonstrates a case of positive antinuclear antibodies and arthritis in a patient with lung adenocarcinoma, which can be falsely diagnosed as systemic lupus erythematosus.