Sarcoidosis with Intraabdominal Involvement Mimicking Lymphoma: A Diagnostic Pitfall

Background Sarcoidosis is a multisystem granulomatous disease with various manifestations. While pulmonary involvement is most common, intra-abdominal sarcoidosis is rare and often mimics malignancy, leading to misdiagnosis and delayed therapy. Case Presentation: We describe an elderly woman who was initially misdiagnosed with lymphoma at another center based on imaging demonstrating intra-abdominal lymphadenopathy and ascites and histopathological findings. She was started on corticosteroids in preparation for chemotherapy. Patient develooped recurrent ascites requring repeated paracentesis. However, reevaluation at our institution revealed non-caseating granulomas without malignant cells on omental biopsies. Additional investigations confirmed bilateral hilar and mediastinal lymphadenopathy, and comprehensive microbiological workup excluded infectious causes, including tuberculosis. Following a course of corticosteroid therapy, the patient experienced complete resolution of symptoms and near-complete radiologic improvement on follow-up PET imaging. Conclusion This case underscores the diagnostic challenges posed by sarcoidosis with atypical intra-abdominal involvement. Careful histological evaluation is critical to avoid misdiagnosis and inappropriate treatment. Familiarity with such uncommon clinical manifestations is critical for the accurate differentiation of sarcoidosis from other differential diagnosis, notably lymphoma, thereby ensuring timely initiation of effective therapy.