Table 1.

Differential diagnosis of the most common malignant primary small bowel neoplasms

	Location	Typical signs
Adenocarcinoma	Duodenum, proximal jejunum	Short segment affected; high-grade small bowel obstruction
Carcinoid	Ileum (appendix)	Desmoplastic reaction mesentery; calcification; hypervascular liver metastases
Lymphoma	Ileum	Long segment affected; luminal narrowing without small bowel obstruction; lymphadenopathy
Malignant GIST	Jejunum (stomach)	Large mass, exophytic; central necrosis; calcification
Leiomyosarcoma	Jejunum, ileum, Meckel's diverticulum	Solitary large mass; cavitation, ulceration, fistula