DX: Extra-adrenal pheochromocytoma (Paraganglioma)

Ok thank you for your comments. It was the first time that this blog reaches so far countries overseas..ok here is the conclusion.

Patient with long standing recurrent hypertension. CT was made first to discard renal artery stenosis as a cause of refractory hypertension. The mass was an incidental finding that turned out to be the actual cause of her illness.

It was an heterogeneous mass with irregular borderline, highly vascular and rapid enhancement with slow washout, located in the left retroperitoneum, lateral to aorta and anterior to psoas muscle along the Zuckerkandl organ. It had a nurturing artery from the posterior aspect of aorta below renal arteries and a draining venous vessel in direction of ipsilateral iliac vein. Renal arteries are spare.

Here is the descriptive image:

Pheochromocitoma has some imaging characteristics but is known as a "chamaleon" for it's wide variations of presentation and location. They are tumors arise from the chromaffin cells of the adrenal medulla and are associated with increased catecholamine production (cause of hypertension). Although chromaffin tissue is also present elsewhere in the body, such as in the mediastinum, along the aorta, and in the pelvis, the term pheochromocytoma is reserved for tumors that arise from the adrenal medulla. Chromaffin cell tumors at other locations are more appropriately called paragangliomas or chemodectomas, although the term extra-adrenal pheochromocytoma is still applied. Pheochromocytoma has been called the 10% tumor because approximately 10% are bilateral, 10% are malignant, 10% occur in children, and 10% are extraadrenal. Malignancy is usually established by local invasion or metastases to nonchromaffin tissues.

Extra-adrenal pheochromocytomas arise also from the sympathetic paraganglia. Sympathetic ganglia are found predominantly in the paraaxial region of the trunk along the prevertebral and paravertebral sympathetic chains and in the connective tissue in or near the walls of pelvic organs. They are associated with the celiac, superior mesenteric, and inferior mesenteric ganglia, which are retroperitoneal in location. The organ of Zuckerkandl is the only macroscopic extraadrenal sympathetic paraganglion, located at the origin of inferior mesenteric artery. Sympathetic ganglia are particularly numerous along the fibers of the inferior hypogastric plexus, leading to and entering the urogenital organs.

AV Malformation and Sclerosing mesenteritis were the differentials given. AVM ussually has more gastrointestinal hemmoraghe manifestations but is a good possiblity, although the presence of refractory hypertension almost rules out this option.

Sclerosing mesenteritis is part of a spectrum (including mesenteric lipodystrophy and mesenteric panniculitis) of idiopathic primary inflammatory and fibrotic processes that affect the mesentery. Pathophysiologically, these processes may affect the integrity of the gastrointestinal lumen and mesenteric vessels by a mass effect. This is not the case.

We have to rely on bloodwork and urine analisis to establish diagnosis so recommend plasmatic metanephrine, vanil mandelic acid and a  24hrs-urine cllection of catecolamines.


http://emedicine.medscape.com/article/379861-overview
http://www.ajronline.org/content/184/3/860.full
http://www.uptodate.com/contents/sclerosing-mesenteritis



Thank you for your comments and suggestions are welcome!