title: Adenocarcinoma of the ileum: A rare and challenging entity.
abstract: BACKGROUND
  Primary small bowel malignancy is unusual and accounts for 1-3% of all gastrointestinal tract neoplasms. Adenocarcinoma is one of the most common histologic types, but its frequency decreases with more distal locations. Its clinical presentation is nonspecific and is usually associated with advanced disease, which contributes to delayed diagnosis.
  
  
  METHODS
  A 66-year-old woman was admitted to the hospital with a 6-day history of progressively worsening abdominal pain localized in the right lower quadrant, nausea, and vomiting. Investigation revealed an inflammatory appendiceal tumor. The patient underwent surgery and an unexpected tumor involving the distal ileal segment and ileocecal appendix was found. Right radical hemicolectomy with en bloc resection of the distal ileum was performed. Histopathological examination revealed adenocarcinoma of the ileum.
  
  
  CONCLUSIONS
  This rare entity is associated with a nonspecific clinical presentation that contributes to delayed diagnosis and treatment, and consequently to a worse prognosis. Approximately half of the cases are only diagnosed at surgery. Primary treatment consists of wide resection with locoregional lymphadenectomy. The role of adjuvant chemotherapy has yet to be determined.
  
  
  CONCLUSIONS
  This case demonstrates an unusual condition characterized by late and challenging diagnosis. We highlight the importance of an earlier diagnosis and optimal treatment for improved patient outcomes.
authors.affiliation: Department of Surgery, Hospital de São José, Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Celso
authors.initials: C
authors.lastname: Nabais
authors.affiliation: Department of Surgery, Hospital de São José, Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Raquel
authors.initials: R
authors.lastname: Salústio
authors.affiliation: Department of Surgery, Hospital de São José, Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Francisco V
authors.initials: FV
authors.lastname: Sousa
authors.affiliation: Department of Surgery, Hospital de São José, Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Eusébio
authors.initials: E
authors.lastname: Porto
authors.affiliation: Department of Surgery, Hospital de São José, Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Cardoso
authors.affiliation: Department of Surgery, Hospital de São José, Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: Caldeira
authors.initials: C
authors.lastname: Fradique
keywords: Adenocarcinoma of the ileum; CT, computed tomography; MRI, magnetic resonance imaging; Right hemicolectomy; SBA, small bowel adenocarcinoma; Small bowel adenocarcinoma; Small bowel neoplasm