**5.1 Diagnosis**

Diagnosis of pheochromocytoma requires a high index of suspicion. Preconception screening of families known to have MEN 2 with RET proto-oncogene is essential. The diagnosis should be considered in pregnant women with severe or paroxysmal hypertension, particularly in the first half of pregnancy or in association with orthostatic hypotension or episodic symptoms of pallor, anxiety, headaches, palpitations, chest pain, or diaphoresis. Symptoms may occur or worsen during pregnancy because of the increased vascularity of the tumour and mechanical factors such as pressure from the expanding uterus or fetal movement (Harper et al, 1989). As in nonpregnant women, the diagnosis is usually based upon the results of 24-hour urinary fractionated metanephrines and catecholamines and plasma fractionated metanephrines. If possible, methyldopa and labetolol should be discontinued prior to the investigation as these agents may interfere with the quantification of the catecholamines. MRI is the imaging test of choice in the pregnant women. Stimulation test and 123-I-MIBG scintigraphy are not considered safe for pregnant women.

#### **5.2 Treatment**

Medical therapy should be iniciated with alpha adrenergic blockade (usually phenoxybenzamine) (Stenstrm & Swolin , 1985).

 Ii is started at a dose of 10 mg twice daily, with titration until the hypertension is controlled. Placental transfer of phenoxybenzamine occurs, but is generally safe (Santeiro et al., 1996). Beta blockade is reserved for treating maternal tachycardia of arrhythmias which persist after full alpha blockade and volume repletion.

Beta blockers may be associated with fetal bradycardia and with intrauterine growth retardation, when used early in pregnancy (Chatterjee & Parekh , 1985) All of these potential fetal risks are small compared to the risk of fetal wastage from unblocked high maternal levels of catecholamines. Hypertensive emergencies should be treated with phentolamine or nitroprusside, although the latter should be limited because of fetal cyanide toxicity.

The timing of surgical excision of the neoplasm is controversial. In the first half of pregnancy, surgical excision may proceed once adequate alpha-blockade is established, although there is a higher risk of miscarriage with first trimester surgery. In the early second trimester, abortion is less likely and the size of the uterus will nor make excision difficult. If

54000 pregnancies (Botchan et al, 1995). As the uterus enlarges and an actively moving fetus compresses the neoplasm, maternal complications such as severe hypertension, hemorraghe into the neoplasm, hemodynamic collapse, myocardial infarction, cardiac arrhythmias, congestive heart failure, and cerebral hemorraghe may occur. Extra-adrenal tumours which occur in 10%, such as in the organ of Zuckerkandl at the aortic bifurcation, are particularly prone to hypertensive episodes with changes in position, uterine contractions, fetal movement, and Valsalva maneuvers. Unrecognized pheochromocytoma is associated with a maternal mortality rate of 50% at induction of anesthesia or during labor (Lau et al., 1996). There is a minimal placental transfer of catecholamines likely due to high placental concentrations of catechol-O-methyltransferase and monoamine oxidase. Adverse fetal effects such hypoxia are a result of catecholamine-induced uteroplacental vasoconstriction and placental insufficiency, and of maternal hypertension, hypotension, or vascular collapse

Diagnosis of pheochromocytoma requires a high index of suspicion. Preconception screening of families known to have MEN 2 with RET proto-oncogene is essential. The diagnosis should be considered in pregnant women with severe or paroxysmal hypertension, particularly in the first half of pregnancy or in association with orthostatic hypotension or episodic symptoms of pallor, anxiety, headaches, palpitations, chest pain, or diaphoresis. Symptoms may occur or worsen during pregnancy because of the increased vascularity of the tumour and mechanical factors such as pressure from the expanding uterus or fetal movement (Harper et al, 1989). As in nonpregnant women, the diagnosis is usually based upon the results of 24-hour urinary fractionated metanephrines and catecholamines and plasma fractionated metanephrines. If possible, methyldopa and labetolol should be discontinued prior to the investigation as these agents may interfere with the quantification of the catecholamines. MRI is the imaging test of choice in the pregnant women. Stimulation test and 123-I-MIBG scintigraphy are not considered safe for

Medical therapy should be iniciated with alpha adrenergic blockade (usually

 Ii is started at a dose of 10 mg twice daily, with titration until the hypertension is controlled. Placental transfer of phenoxybenzamine occurs, but is generally safe (Santeiro et al., 1996). Beta blockade is reserved for treating maternal tachycardia of arrhythmias which persist

Beta blockers may be associated with fetal bradycardia and with intrauterine growth retardation, when used early in pregnancy (Chatterjee & Parekh , 1985) All of these potential fetal risks are small compared to the risk of fetal wastage from unblocked high maternal levels of catecholamines. Hypertensive emergencies should be treated with phentolamine or nitroprusside, although the latter should be limited because of fetal

The timing of surgical excision of the neoplasm is controversial. In the first half of pregnancy, surgical excision may proceed once adequate alpha-blockade is established, although there is a higher risk of miscarriage with first trimester surgery. In the early second trimester, abortion is less likely and the size of the uterus will nor make excision difficult. If

(Saarikoski, 1974).

pregnant women.

phenoxybenzamine) (Stenstrm & Swolin , 1985).

after full alpha blockade and volume repletion.

**5.2 Treatment** 

cyanide toxicity.

**5.1 Diagnosis** 

the pheochromocytoma is not recognized until the second half of gestation, increasing uterine size makes surgical exploration difficult (Sarathi et al,. 2010).

Successful laparoscopic excision of a pheochromocytoma in the second trimester of pregnancy has been described (Finkensted et al, 1999).

Other options include combined cesarean delivery and tumour resection or delivery followed by tumour resection at a later date. Delivery is generally delayed until the fetus reaches sufficient maturity to reduce postpartum morbidity, providing successful medical management exists. Although successful vaginal delivery has been reported, it has been associated with higher rates of maternal mortality than caesarean section (Schenker & Granat, 1982).
