Fig. 1: Axial T2-weighted MR image with fat suppression shows a well circumscribed retroperitoneal soft tissue mass below the aortic bifurcation with heterogeneous high T2 signal intensity.
Fig. 2: Post contrast MR image shows heterogeneous enhancement of the mass.
- 10% of all pheochromocytoma
- Most in the abdomen (98%)
- Along prevertebral and paravertebral ganglia, including the organ of Zuckerkandl (which is the only macroscopic extraadrenal sympathetic paraganglia located at the origin of inferior mesenteric artery)
- Benign or malignant difficult to determine by histology. If there is local invasion or metastasis to non-chromaffin tissues --> malignant
- Extraadrenal pheochromocytoma metastasizes more often than adrenal counterpart
- High T2 signal intensity, classic "salt-and-pepper" pattern on T2WI
- Enhancing, usually heterogeneous
- No lipid content (lack of signal dropout on opposed-phase images)