title: Mantle cell lymphoma presenting as acute appendicitis.
abstract: BACKGROUND
  Most cases of appendicitis associated with lymphoma reported in literature are in patients with Burkitt's or large B-cell lymphoma. Mantle cell lymphoma only makes up 4% of all lymphoma cases in the U.S. We report a case of a patient with mantle cell lymphoma presenting with acute appendicitis.
  
  
  METHODS
  A 75 year old male with a history of left cervical lymphadenopathy biopsied to be mantle cell lymphoma presented with right lower abdomen pain for 3 days. An outpatient CT scan revealed acute appendicitis. Laparoscopic appendectomy was performed without any complication. The histologic examination showed mantle cell lymphoma occluding the lumen of appendix.
  
  
  CONCLUSIONS
  Typically, appendicitis is caused by obstruction of the lumen of appendix by fecalith or lymphoma. A previously reported case of a patient with mantle cell lymphoma who developed appendicitis received chemotherapy before appendectomy. The author could not determine how mantle cell lymphoma contributed to appendicitis because the lumen of appendix was not occluded by the lymphoma, likely from cytoreduction from chemotherapy. We have a patient with mantle cell lymphoma before the patient received chemotherapy who presented with appendicitis. The appendiceal specimen shows the lumen filled with mantle cell lymphoma.
  
  
  CONCLUSIONS
  This is a rare case of mantle cell lymphoma causing obstruction of appendiceal lumen and subsequently appendicitis, unaffected by chemotherapy.
authors.affiliation: Surgery Department, Lutheran Medical Center, 150 55th Street, Brooklyn 11220, NY, USA. Electronic address: mchae@lmcmc.com.
authors.forename: Max
authors.initials: M
authors.lastname: Chae
authors.affiliation: Surgery Department, Lutheran Medical Center, 150 55th Street, Brooklyn 11220, NY, USA. Electronic address: skumar@lmcmc.com.
authors.forename: Sampath
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Pathology Department, Lutheran Medical Center, 150 55th Street, Brooklyn 11220, NY, USA. Electronic address: mcheema@lmcmc.com.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Cheema
keywords: Appendicitis; Chemotherapy; Mantle cell lymphoma; Obstruction of appendiceal lumen