title: Duodenal metastasis from lung adenocarcinoma: A rare cause of melena.
abstract: BACKGROUND
  We report a rare case of duodenal metastasis from primary lung adenocarcinoma presented with history of melena and weight loss.
  
  
  METHODS
  A 52-year-old smoker man presented with six months history of epigastric pain, melena and weight loss. Esophago-gastroduodenoscopy revealed a 10mm ulcerative lesion in the fourth part of duodenum. Histopathology of resected lesion showed poorly differentiated adenocarcinoma. Tumor cells showed immunopositivity for cytokeratin-7 (CK7), thyroid transcription factor 1 (TTF-1), and immunonegativity for CK20, Villin, CDX2 and thyroglobulin, supporting the diagnosis of metastatic adenocarcinoma of the lung origin. Computed tomography (CT) of chest revealed left hilar mass encasing the main pulmonary artery associated with ipsilateral hilar and contralateral mediastinal lymphadenopathy. Bronchoscopy assisted biopsy of lung mass confirmed the diagnosis of primary adenocarcinoma. Patient was staged as T4N3M1. After the resection of duodenal metastasis followed by three cycles of cisplatinum based chemotherapy with Bevacizumab, melena resolved completely.
  
  
  CONCLUSIONS
  Duodenal metastases from lung adenocarcinoma are extremely uncommon, and rarely produce symptoms. Most of cases require duodenectomy or pancreatico-duodenectomy for symptomatic relief. For smaller duodenal metastatic lesions (≤1cm) endoscopic resection is a feasible therapeutic option.
  
  
  CONCLUSIONS
  Although rare, duodenal metastasis from lung adenocarcinoma should also be included in the differential diagnosis of melena. Smaller lesions (≤1cm) can safely be managed with endoscopic resection.
authors.affiliation: King Saud University, Riyadh, Saudi Arabia. Electronic address: ealsaeed@yahoo.ca.
authors.forename: Eyad Fawzi
authors.initials: EF
authors.lastname: AlSaeed
authors.affiliation: King Fahad Medical City, Riyadh, Saudi Arabia. Electronic address: mkhairuddin@kfmc.med.sa.
authors.forename: Mutahir A
authors.initials: MA
authors.lastname: Tunio
authors.affiliation: King Fahad Medical City, Riyadh, Saudi Arabia. Electronic address: kalsayari@kfmc.med.sa.
authors.forename: Khalid
authors.initials: K
authors.lastname: AlSayari
authors.affiliation: King Fahad Medical City, Riyadh, Saudi Arabia; Comprehensive Cancer Center, King Fahad Medical City, Riyadh 59046, Saudi Arabia. Electronic address: saldandan@kfmc.med.sa.
authors.forename: Sadiq
authors.initials: S
authors.lastname: AlDandan
authors.affiliation: King Fahad Medical City, Riyadh, Saudi Arabia; Comprehensive Cancer Center, King Fahad Medical City, Riyadh 59046, Saudi Arabia. Electronic address: kalsayari@kfmc.med.sa.
authors.forename: Khalid
authors.initials: K
authors.lastname: Riaz
keywords: Duodenal metastasis; Endoscopic resection; Lung adenocarcinoma; Melena