List nine causes of duodenal obstruction

1. Peptic ulcer disease
2. Pancreatitis
3. Congenital annular pancreas
4. Pancreatic neoplasia (e.g., pancreatic carcinoma)
5. Duodenal neoplasia (e.g., duodenal adenocarcinoma)
6. Metastasis
7. Intraluminal diverticulum (windsock deformity, caused by duodenal web)
8. SMA syndrome
9. Hematoma