Probable Acquired Autosplenectomy in Systemic Lupus Erythematosus and Sjögren's Overlap Syndrome: A Case Report With Serial Imaging Evidence.

Autosplenectomy, defined as the spontaneous loss of splenic tissue in the absence of trauma or surgery, is most commonly associated with sickle cell disease and is rarely described in patients with autoimmune conditions. We present a case of a 54-year-old woman with systemic lupus erythematosus (SLE) and Sjögren's overlap syndrome who was incidentally found to have a complete absence of the spleen on computed tomography (CT), despite prior imaging demonstrating a normal splenic anatomy. The patient presented with polyarthralgia, fatigue, and systemic inflammation. Laboratory investigations revealed elevated anti-dsDNA titers, hypocomplementemia, and a positive extractable nuclear antigen (ENA) profile. Imaging confirmed splenic absence, and extensive evaluation excluded infectious, malignant, infiltrative, and hematological causes of splenic agenesis. Serial imaging findings, combined with the presence of an active autoimmune disease, supported the diagnosis of a probable autoimmune-mediated autosplenectomy. This case highlights a rare but clinically significant manifestation of systemic autoimmune diseases. Recognition of asplenia is critical because of the associated risk of overwhelming infection, necessitating vaccination and the implementation of prophylactic strategies. Clinicians should consider splenic dysfunction in patients with autoimmune diseases, particularly when unexplained infections or atypical imaging findings are present.