paraganglion

from The Century Dictionary.

• noun One of the crescentic or oval groups of cells in the medullary portion of the adrenal bodies.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A chromaffin body; a small group of chromaphil cells in the abdomen, connected with the ganglia of the sympathetic trunk and the ganglia of the celiac, renal, adrenal, aortic and hypogastric plexuses.