Palpitations and Hypertension During Pregnancy

Perioperatively, the patient was closely monitored and remained hemodynamically stable.  An elective Cesarean section was subsequently performed at 37 weeks’ gestation after concern for fetal bradycardia, with delivery of a healthy baby.

Discussion

Pheochromocytomas are a rare event and are an even rarer occurrence during pregnancy, with an incidence of approximately 0.007%.1 The diagnosis is particularly important to consider during pregnancy, as an undiagnosed and/or untreated pheochromocytoma has a high maternal and fetal mortality rate, ranging from 15% to 25% in some studies1, 2 to as high as 40% to 50% in others.3 Although pheochromocytoma associated with pregnancy is a rare disease, an increased clinical suspicion must be maintained given the reduction in mortality with medical treatment and surgical resection.3

The most common presenting symptom of a pheochromoctyoma during pregnancy is uncontrolled hypertension, either paroxysmal or sustained.  Accompanying symptoms include diaphoresis, palpitations and impaired glucose tolerance.4 In one study of 15 pregnant women presenting with pheochromocytoma during pregnancy, the classic triad of hypertension, headache and sweating was only seen in three women, whereas palpitations, headaches and diaphoresis associated with headaches were noted in five pregnant women.5 Additional, less common presenting symptoms have been reported including dyspnea, chest pain, seizures and postpartum pulmonary edema.6

Hypertension due to a pheochromocytoma during pregnancy is often mistakenly attributed to preeclampsia, particularly in the setting of proteinuria, which can delay the diagnosis. Certain features can help distinguish between the two diseases. For instance, preeclampsia typically manifests in the latter part of pregnancy, whereas pheochromocytomas can present at any time during pregnancy. If not diagnosed intrapartum, the hypertension of pheochromocytoma persists after delivery, whereas preeclampsia resolves.7

Similar to the nonpregnant state, pheochromocytomas are typically unilateral and sporadic, with 10% occurring as bilateral, malignant or familial.  Examples of familial disorders associated with pheochromocytoma are multiple endocrine neoplasia II, von Hippel-Lindau syndrome and type 1 neurofibromatosis.2, 1

Establishing the diagnosis in the nonpregnant state is similar to the pregnant state, namely quantifying 24-hour urinary fractionated metanephrines and catecholamines and plasma fractionated metanephrines at least twice the upper limit of the normal range. Under normal circumstances, pregnancy and preeclampsia should not influence catecholamine levels.7

In the setting of a high clinical suspicion for a pheochromocytoma, MRI without gadolinium and/or ultrasound is recommended during pregnancy as an imaging modality. Ultrasound is often limited by the gravid uterus and has limited utility in diagnosing extraadrenal tumors.