A Rare Case of Systemic Lupus Erythematosus in an Elderly Male With an Incidental Lung Mass: A Case Report.

Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown etiology that affects multiple organ systems. This disease primarily affects women of childbearing age but can have severe outcomes and a rare incidence in males. The incidence of SLE in males peak at 45-60 years of age. In this case, we present a rare instance of SLE in a 70-year-old male who presented with progressive shortness of breath, generalized weakness, and weight loss. Laboratory tests revealed anemia, thrombocytopenia, increased creatinine levels, and urine proteinuria. Diagnostic imaging showed an incidental lung mass and bilateral pleural effusion, and serological investigations revealed positive results for Antinuclear Antibody (ANA), Anti-ds-DNA, Anti-MPO, Anti-PR3, Anti-CCP, Anti-cardiolipin IgM, and Anti-RNP, along with low C3 and C4 levels. A renal biopsy confirmed the presence of lupus nephritis, and the patient was initiated on hydroxychloroquine 200 mg and a methylprednisolone pulse dose of 1 gm, which was subsequently transitioned to oral prednisolone along with mycophenolate mofetil. The patient responded well to treatment, showing improvements in anemia, thrombocytopenia, and pleural effusion.