Small bowel aneurysmal dilatation is a common pattern of disease in the small bowel. It consists of a focal segment of dilated small bowel associated with a mass. The mass is typically circumferential. The mnemonic
MALL can be used to recall the common diagnoses.
| Disease | Notes |
| M | Malignant GIST | Lymphadenopathy absent; obstruction common |
| A | Adenocarcinoma of small bowel |
|
| L | Lymphoma | Lymphadenopathy present; obstruction uncommon |
| L | Leiomyosarcoma |
|
Metastatic disease can also present with small bowel aneurysmal dilatation. The most common primary is melanoma, followed by lung, breast, and colon cancer. Metastases tend to be multifocal and necrotic.
