Late-Onset Systemic Lupus Erythematosus Presenting as Acute Bowel Obstruction Due to Mesenteric Panniculitis and Severe Pancytopenia: A Case Report

Abstract

Background: Systemic lupus erythematosus (SLE) with onset after the age of 50 years accounts for approximately 10–20% of cases and is often associated with atypical clinical features and delayed diagnosis. Gastrointestinal involvement as an initial manifestation is uncommon, and mesenteric panniculitis complicated by bowel obstruction is exceptionally rare. Case Presentation: We report the case of a 63-year-old woman admitted for acute bowel obstruction manifested by fecaloid vomiting and cessation of flatus and stool for four days. Abdominal computed tomography revealed small bowel obstruction associated with mesenteric fat infiltration suggestive of mesenteric panniculitis, without evidence of a mechanical transition point. Alternative diagnoses, including infectious, neoplastic, and other inflammatory causes, were investigated and excluded based on clinical, biological, and radiological findings. Serum complement levels were reduced, supporting active autoimmune disease. Laboratory investigations showed severe pancytopenia (hemoglobin 9 g/dL, lymphocytes 300/mm³, platelets 22,000/mm³) with normal bone marrow findings, suggesting peripheral immune-mediated cytopenia. Clinical examination revealed oral and nasal ulcerations and inflammatory arthralgia. Immunological testing demonstrated positive antinuclear antibodies (1:640, homogeneous pattern), markedly elevated anti–double-stranded DNA antibodies (>300 IU/mL), and positive anti-Sm and anti-ribosomal P antibodies. The diagnosis of SLE was established according to the 2019 ACR/EULAR classification criteria (Aringer et al., 2019). Systemic corticosteroid therapy (prednisone 1 mg/kg/day) led to rapid resolution of gastrointestinal symptoms and progressive improvement of hematological abnormalities. At two months of follow-up, the patient remained clinically stable under progressive corticosteroid tapering. Conclusion: Late-onset SLE may present with atypical and misleading manifestations, including acute gastrointestinal emergencies mimicking surgical conditions. Early recognition is essential to avoid unnecessary surgical interventions and initiate appropriate immunosuppressive therapy.