Acute Appendicitis Or Appendiceal Lymphoma: Diffuse Large B Cell Lymphoma Presenting as Appendicitis: A Case Report and Review of the Literature

Introduction: Primary appendiceal lymphoma is an extremely rare neoplasm, representing approximately 0.015% of gastrointestinal lymphomas. We present a case of a young woman with acute appendicitis whose surgical specimen revealed an atypical lymphoid proliferation. Case Presentation: A 21-year-old female presented with colicky epigastric pain evolving over two weeks. Physical examination revealed right iliac fossa tenderness with a positive McBurney’s sign. Laboratory studies showed leukocytosis (12,200/μL) with neutrophilia. Abdominal ultrasound demonstrated a hypoechoic lesion in the right iliac fossa (56 × 30 mm) with peripheral hypervascularity on Doppler. Laparoscopic appendectomy was performed, revealing a markedly edematous appendix with concentric wall thickening of neoplastic appearance. Histopathological examination confirmed diffuse large B-cell lymphoma, activated B-cell subtype, with a Ki 67 proliferation index of 75%, consistent with primary appendiceal lymphoma. Discussion: Appendiceal lymphomas constitute fewer than 0.015% of gastrointestinal lymphomas and present a diagnostic challenge given their nonspecific clinical picture. B cell non Hodgkin lymphoma is the predominant subtype. Simple appendectomy may be curative in localized disease; however, multidisciplinary oncologic evaluation is essential. Conclusion: Primary appendiceal lymphoma should be considered in the differential diagnosis of appendiceal tumors. Pathological examination of all appendectomy specimens is mandatory to ensure accurate diagnosis and appropriate oncologic management.