title: Persistent Afebrile Abdominal Pain: An Unusual Case of Segmental Colitis in an Immunocompromised Host.
abstract: In this report we describe a case of a 66-year-old woman who presented with right upper quadrant abdominal pain and bloody diarrhea. A workup revealed immunodeficiency, an immunologic profile with low complement levels resembling systemic lupus erythematosus, and a circumferential colonic wall lesion located in the ascending colon. After endoscopy and biopsy, the mass lesion was attributed to "double hit" diffuse large B-cell lymphoma, categorized as high grade large B-cell non-Hodgkin lymphoma according to the most recent revised 2016 World Health Organisation classification and considered to be a rare and highly aggressive tumor. The diagnosis of colonic lymphoma can be challenging due to a diversity of clinical presentation and requires a high index of suspicion. As the literature of such documented reports is limited, this case suggests further investigations.
  
  
  BACKGROUND
  GI: gastrointestinal tract, DLBCL: diffuse large B cell lymphoma, DH: double hit lymphoma, SLE: systemic lupus erythematosus, ANA: antinuclear antibodies, anti-ssDNA: anti-single-stranded DNA, BCL: B-cell lymphoma protein, MUM-1/IRF4: multiple myeloma oncogene 1/interferon regulatory factor 4, HGBL: high grade B-cell lymphoma, anti-dsDNA: anti-double-stranded DNA.
authors.affiliation: 4th Internal Medicine Department, "Evangelismos" General Hospital, Athens, Greece.
authors.forename: Ilias P
authors.initials: IP
authors.lastname: Papakonstantinou
authors.affiliation: 4th Internal Medicine Department, "Evangelismos" General Hospital, Athens, Greece.
authors.forename: Emmanuel A
authors.initials: EA
authors.lastname: Andreadis
keywords: colonic lymphoma; double hit; drug-induced lupus; gastrointestinal vasculitis; immunodeficiency; non-hodgkin lymphoma; segmental colitis