Pheochromocytoma

1
Pheochromocytoma

• Maria E. Ferris, MD, MPH

2
Epidemiology

• Mean Age in children 11 years
• Male 21 female
• Bilateral in 20 of cases
• 35 Malignant

3
PATHOLOGY

• It is a tumor of neuroendocrine origin first
  described by Frankel in 1886.
• In the 5th gestational week, neuroblasts migrate
  from the thoracic neural crest to form the
  sympathetic chains and preaortic ganglia (thought
  to be the precursors of neuroblastomas and
  ganglioneuromas.

4
Pathology (2)

• In the 7th week, a second migration of cells
  (chromaffin cells) occurs to form the adrenal
  medullae to
• the sympathetic ganglia, the vagus nerve,
  paraganglia of the carotid arteries, the arch of
  the aorta, and the abdominal aorta.
• Less commonly to the wall of the urinary bladder,
  the prostate, behind the liver, the hepatic and
  renal hila, and near the rectum and the gonads.
• Pheochromocytomas and paragangliomas arise from
  these chromaffin cells.

5
Nomenclature

• Paraganglioma is any extra-adrenal tumor of the
  paraganglion system.
• Tumors in the head, neck, and paravagal region
  are usually nonfunctioning.
• Tumors around the aorta and sympathetic chain and
  visceral tumors, such as bladder tumors, usually
  elaborate catecholamines

6
Tumor Location

• 50 arise in the adrenal medulla.
• Most extra-adrenal pheochromocytomas (functional
  paragangliomas) occur in the abdomen along the
  great vessels -most commonly in the upper
  periaortic region from the diaphragm to the lower
  poles of the kidneys-
• Extra-adrenal tumors may also occur at the base
  of the brain, in the chest (including the heart
  and pericardium), or paratesticularly

7
Characteristics

• Size from 2 to 3600 g. and are typically not
  encapsulated.
• Microscopically, they are composed of nests or
  cords of polyhedral cells separated by a
  fibrovascular stroma. Nuclear pleomorphism does
  not correlate with malignant behavior

8
Malignancy

• Malignancy is Dxd clinically based on the
  presence of extensive local invasion or
  metastatic disease.
• Metastases must be distinguished from multifocal
  tumors occurring elsewhere in areas of neural
  crest tissue.

9
Presentation and Dx

• Usualc/o related to catecholamine production.
• Patients have ? stores of catecholamines in
  sympathetic nerves norepinephrine released from
  these terminals has easier access to receptors on
  the effector cells.

10
Presentation and Dx (2)

• The catecholamine-induced symptoms are mediated
  by the normal sympathetic neural pathway and not
  primarily by serum catecholamines.
• Any direct stimulus to the sympathetic nervous
  system can induce a crisis without a large rise
  in serum catecholamine levels.
• Blood pressure may sometimes be normal despite
  high serum levels of catecholamines.