Pheochromocytoma in Pregnancy

Abstract

DiscussionPheochromocytoma during pregnancy remains a rare condition, occurring in 0.007% in one 22-year review of 30,426 pregnancies [1]. However, pheochromocytomas in pregnancy are associated with high maternal and fetal mortality (8% and 17%, respectively) in addition to fetal growth restriction and prematurity [2,3]. Antenatal diagnosis has been shown to reduce maternal and fetal mortality with early pharmacologic and surgical intervention [4].Diagnosis of pheochromocytoma is frequently challenging but even more so if needs to be made during the pregnancy. One of the examples is a case of a 29 year-old G2P1011 female was referred to endocrine clinic for elevated plasma metanephrines that were checked in the setting of hypertension associated with headaches and hyperhidrosis that persisted following a spontaneous abortion at 30 weeks gestation.The patient had a history of gestational hypertension during her first pregnancy, but had not routinely checked her blood pressure since her previous delivery 2 years prior. Early in her second pregnancy she began to develop episodes of paroxysmal headaches, palpitations, and heat intolerance associated with elevated blood pressure. She was diagnosed with gestational hypertension and diabetes in the first trimester and placed on bed rest. Despite the start of labetalol in pregnancy, she continued to have ongoing hypertension with episodic adrenergic symptoms. These symptoms persisted after the pregnancy loss. She remained on labetalol therapy after the pregnancy. CT adrenal protocol showed a 3.7 cm mass replacing the left adrenal with poor washout on delayed imaging. Labetalol was discontinued and she was switched to phenoxybenzamine with left laparoscopic adrenalectomy two months after initial laboratory diagnosis.Pheochromocytoma is often misdiagnosed as pregnancy induced hypertension (PIH), which remains the most common complication of pregnancy. However, there are some key differences that can aid in distinguishing the two entities. PIH rarely occurs prior to 20 weeks gestation, while symptomatic pheochromocytoma can present at any point during pregnancy. Pheochromocytoma often presents with paroxysmal hypertension associated with headache, palpitations (40%), hyperhidrosis (35%), and anxiety (18%) [5]. Idiopathic hypertension and PIH can often progress to preeclampsia, which is associated with proteinuria, leg edema, and extra weight gain during pregnancy. High uric acid, liver function abnormalities, and coagulopathies are more common in PIH and hyperglycaemia can be seen in either condition [6]. Cardiomyopathy during pregnancy or in early post-partum should also raise the index of suspicion for pheochromocytoma [7].One difficulty in distinguishing the two entities is that both plasma and urine metanephrines and catecholamine's can be elevated in PIH, as much as 1.6 to 2.6 fold in one study [8]. However, other studies have reported that catecholamine's are not elevated in normotensive pregnant women or preeclampsia [9]. It should be noted that some medications use...