Organ of Zuckerkandl

The Organ of Zuckerkandl (or paraaortic bodies) is a chromaffin body derived from neural crest located at the bifurcation of the aorta or at the origin of the inferior mesenteric artery.

Function
Its physiological role is thought to be of greatest importance during the early gestational period as a homeostatic regulator of blood pressure, secreting catecholamines into the fetal circulation.

The organ itself regresses in the late third trimester and following birth to form the aorticosympathetic group of the adult paraganglia.

Pathology
The Organ of Zuckerkandl is of pathological significance in the adult as the most common extra-adrenal site of pheochromocytoma (paraganglioma). Extra-adrenal tumors account for around 10% of all cases of pheochromocytoma.

Eponym
This diffuse group of neuroendocrine sympathetic fibres was first described by Emil Zuckerkandl, a professor of anatomy at the University of Vienna, in 1901.

Nomenclature
Some sources equate the "aortic bodies" and "paraaortic bodies", while other sources explicitly distinguish between the two. When a distinction is made, the "aortic bodies" are chemoreceptors which regulate circulation, while the "paraaortic bodies" are the chromaffin cells which manufacture catecholamines.