Primary adenocarcinoma of the small intestine occurs in over 50% of cases in the duodenum. However, its location in the third and fourth duodenal portions occurs rarely and is a diagnostic challenge. The aim of this work is to report an adenocarcinoma of the third and fourth duodenal portions, emphasizing its diagnostic difficulty and the value of video capsule endoscopy. A man, 40 years old, with no medical history, with abdominal discomfort and progressive fatigue, presented four months ago with one episode of moderate melena. The physical examination was normal, except for mucosal pallor. Blood tests were consistent with microcytic, hypochromic iron deficiency anemia with 7.8 g/dL hemoglobin. The upper and lower endoscopy were normal. Additional work-up with video capsule endoscopy showed a polypoid lesion involving the third and fourth portions of the duodenum. Biopsy showed a moderately differentiated adenocarcinoma. Abdominal computed tomography showed a wall thickening from the third duodenal portion to the proximal jejunum, without distant metastasis. The patient underwent segmental resection (distal duodenum and proximal jejunum) with duodenojejunostomy. The surgical specimen histology confirmed the biopsy diagnosis, with transmural infiltration, without nodal involvement.
Conclusion: Adenocarcinoma of the third and fourth portions of the duodenum is difficult to diagnose and capsule endoscopy is of great value.
Keywords: Adenocarcinoma; Duodenal cancer; Duodenum; Endoscopy; Video capsule endoscopy.