Pheochromocytomas are rare tumors that arise from the adrenal medulla or other autonomic ganglia. They produce, store, and secrete high levels of catecholamines like epinephrine and norepinephrine. Most pheochromocytomas are benign tumors located in one adrenal gland, though some are malignant or bilateral. They can cause sustained or episodic hypertension and related symptoms like headaches and sweating. Diagnosis involves urine tests detecting elevated catecholamine metabolites. Preoperative treatment with alpha blockers and fluid expansion helps reduce surgical risks from blood pressure fluctuations and related complications.

1. PHEOCHROMOCYTOMA

2.  These tumors arising from adrenal
medulla produce, store, and secrete
catecholamines.
 Paragangliomas are tumors that
arise from autonomic ganglia and
behave pathophysiologically like
pheochromocytomas
 Most pheochromocytomas secrete
both epinephrine and
norepinephrine, with the fraction of
secreted norepinephrine being
greater than that secreted by the
normal gland.

3.  Most (85% to 90%) pheochromocytomas are solitary
tumors localized to a single adrenal gland, usually
the right
 Approximately 10% of adults and 25% of children
have bilateral tumors.
 Malignant spread of these highly vascular tumors
occurs in approximately 10% of cases.
 It may be part of the multiple endocrine neoplasia
(MEN) IIA or IIB.
1)Type IIA includes medullary carcinoma of the
thyroid, parathyroid hyperplasia, and
pheochromocytoma;
2) type IIB consists of medullary carcinoma of
the thyroid, pheochromocytoma, and neuromas of
the oral mucosa.

4. Clinical Presentation
 Most common in young to middle adult life.
 clinical manifestations are mainly due to the
pharmacologic effects of the catecholamines
released from the tumor.
 sustained hypertension maybe present although
occasionally it is paroxysmal.
 When true paroxysms occur, the blood pressure
may rise to alarmingly high levels, placing the
patient at risk for cerebrovascular hemorrhage,
heart failure, dysrhythmias, or myocardial
infarction.

5.  Headache, palpitations, tremor, profuse
sweating, and either pallor or flushing may
accompany an attack.
Diagnosis:
 Urinary vanillylmandelic acid and unconjugated
norepinephrine and epinephrine levels are
measured in a 24-hour urine collection and are
expressed as a function of the creatinine
clearance
 Excess production of metabolites of
catecholamines is diagnostic for
pheochromocytoma.

6. Anesthetic Considerations
Preoperative Preparation:
 Perioperative blood pressure fluctuations,
myocardial infarction, congestive heart failure,
cardiac dysrhythmias, and cerebral hemorrhage
all appear to be reduced in frequency when the
patient has been treated before surgery with α-
blockers and the intravascular fluid compartment
has been re-expanded.