What is a Chromaffin reaction?

What is a Chromaffin reaction?

The freshly cut tumor surface turns dark brown (right half of image) when immersed in potassium dichromate solution (pH between 5 and 6). This is due to oxidation of stored catecholamines synthesized by the tumor and is known as the Chromaffin Reaction.

What is the confirmatory test for pheochromocytoma?

The most commonly ordered blood test for pheochromocytoma is the plasma free metanephrine test. Though more convenient to obtain than a 24-hour urine collection, plasma free metanephrine testing is plagued by frequent false positive results.

How does pheochromocytoma affect blood pressure?

A pheochromocytoma can cause wild fluctuations in blood pressure with normal blood pressure in between spells. This can make the condition more difficult to detect. The graph shows a nine-day period of short, irregular bursts in blood pressure due to a pheochromocytoma.

What does a pheochromocytoma secrete?

Pheochromocytoma is a rare type of tumor that arises in adrenal glands, specifically from certain cells known as chromaffin cells in the center of the adrenal gland called the adrenal medulla. These cells secrete hormones epinephrine and norepinephrine, and the pheochromocytoma continuously overproduces them.

What is the chromaffin system?

The mass of tissue forming paraganglia and medulla of suprarenal glands, which secretes epinephrine and stains readily with chromium salts. Similar tissue is found in the organs of Zuckerkandl and in the liver, testes, ovary, and heart. Synonym: chromaffin tissue.

What triggers chromaffin cells?

In order to activate chromaffin cells, the splanchnic nerve of the sympathetic nervous system releases acetylcholine, which then binds to nicotinic acetylcholine receptors on the adrenal medulla. This causes the release of catecholamines.

How do you confirm pheochromocytoma?

Imaging tests

1. CT scan, a specialized X-ray technology.
2. MRI , which uses radio waves and a magnetic field to produce detailed images.
3. M-iodobenzylguanidine (MIBG) imaging, a scanning technology that can detect tiny amounts of an injected radioactive compound taken up by pheochromocytomas or paragangliomas.

Is blood pressure always high with pheochromocytoma?

Because pheochromocytomas produce large amounts of each of these hormones, the effects on blood pressure are typically very dramatic. Almost all patients with pheochromocytomas have elevated blood pressure, and the hallmark of high blood pressure caused by this condition is extreme blood pressure swings during the day.

Can pheochromocytoma cause low blood pressure?

Hypotension (especially orthostatic) may be seen in patients with pheochromocytoma; it is considered a result of fluctuation in vascular tone and subsequent suppression of baroceptor signaling,10,11,12,13 and/or hypovolemia and/or downregulation of adrenergic receptors. However, sustained hypotension is a rare finding.

What is a chromaffin cell?

Chromaffin cells (CCs) of the adrenal gland and the sympathetic nervous system produce the catecholamines (epinephrine and norepinephrine; EPI and NE) needed to coordinate the bodily “fight-or-flight” response to fear, stress, exercise, or conflict.

What is chromaffin cell tumor?

Background: Chromaffin-cell tumors (CCT), a rare group of catecholamine producing endocrine neoplasms, are traditionally suspected and diagnosed in patients presenting with episodic hypertension, together with the classic triad of headache, sweating, and tachycardia.

How does pheochromocytoma affect the human body?

Pheochromocytoma is a tumor of the chromaffin cells in the adrenal medulla and sympathetic paraganglia, which synthesizes and secretes catecholamines. Norepinephrine, epinephrine, and dopamine all act on their target receptors, which causes a physiological change in the body.

Which is characteristic of pheochromocytoma staining with synaptophysin?

Staining with synaptophysin is a characteristic feature of pheochromocytoma and does not predict a more aggressive disease course. Larger and heavier tumors are associated with more aggressive disease, rather than smaller and lighter tumors.

How are catecholamines released in pheochromocytoma cells?

Tightly regulated by neuronal stimulation (acetylcholine, pituitary adenylate cyclase activating peptide) and multiple peptides thought to participate in negative feedback and autocrine / paracrine regulation Chromaffin cells in pheochromocytoma release catecholamines without sympathetic innervation or neuronal stimulation

Which is a diagnostic test for pheochromocytoma?

E. Synaptophysin, chromogranin, S100. The clinical presentation and image are diagnostic of a pheochromocytoma. Synaptophysin, chromogranin and S100 are positive in pheochromocytoma.AE1/AE3, CK7 and TTF1 are consistent with metastatic lung adenocarcinoma.