Imaging Features Discussion

Diagnosis

3.7cm Extra-adrenal Paraganglioma with a normal adjacent left adrenal gland.

Pathology

Left Adrenal Gland, Resection:

  • Extra-adrenal paraganglioma with atypical features (capsular and vascular invasion present)
    • Tumor dimension: 3.7 x 2.3 x 2.7cm
    • Tumor abuts the inked surface/margin
    • Foci of capsular invasion notes, however, transcapsular invasion is not present.
    • Foci of vascular invasion present
    • Vascular margin is negative
  • Adjacent adrenal gland is unremarkable
  • Surrounding brown fat is noted
  • Tumor associated peripheral nerve bundles and ganglion are present

Imaging Features: Discussion

MRI has been advocated as a first line exam by some to evaluate for functioning paragangliomas as in this case. However, the left adrenal gland was not seen by MRI, and thus an adrenal paraganglioma (aka pheochromocytoma) was favored as the diagnosis by imaging.

This case has very typical MR imaging features of a paraganglioma:

  • Very bright T2 signal relative to all other adrenal lesions.
  • No evidence of microscopic fat on in and out of phase sequences which would be consistent with an adenoma.


Left suprarenal mass with low signal on In and Out of Phase coronal sequences means there is no microscopic fat within the mass.

Discussion