ENDOCRINE DISORDERS IN PREGNANCY: Pheochromocytoma and pregnancy: a deceptive connection

Abstract

A pheochromocytoma in a pregnant patient is one of the most threatening medical conditions for mother, fetus, and physician. Although extraordinarily rare with a frequency of 0.002% of all pregnancies, this tumor is notorious for its devastating consequences. As in non-pregnant patients, the signs and symptoms are quite variable but not specific, with hypertension being one of the most prominent signs. Confusion with the much more prevalent forms of pregnancy-related hypertension is the main cause of overlooking the diagnosis. If undiagnosed, maternal and fetal mortality is around 50%. Conversely, early detection and proper treatment during pregnancy decrease the maternal and fetal mortality to !5 and 15% respectively. For the biochemical diagnosis, plasma or urinary metanephrines are the tests of first choice since they have a nearly maximal negative predictive value. For reliable localization, only magnetic resonance imaging is suitable, with a sensitivity of more than 90%. When the tumor is diagnosed in the first 24 weeks of gestation, it should be removed by laparoscopic adrenalectomy after 10-14 days of medical preparation with the same drugs as in non-pregnant patients. If the tumor is diagnosed in the third trimester, the patient should be managed until the fetus is viable using the same drug regimen as for regular surgical preparation. Cesarean section with tumor removal in the same session or at a later stage is then preferred since vaginal delivery is possibly associated with higher mortality. Despite all technical diagnostic and therapeutic progress over the last decades, the key factor for further reduction of maternal and fetal mortality is early awareness and recognition of the potential presence of a pheochromocytoma in a pregnant patient with hypertension.

ENDOCRINOLOGY IN PREGNANCY: Pheochromocytoma in pregnancy: case series and review of literature

“…As hypertension is a common complication of pregnancy occurring in 5-10% (8), it can be difficult to differentiate between a pheochromocytoma and more common causes of hypertension during pregnancy such as a chronic pre-existing hypertension and pregnancyrelated hypertension (gestational hypertension and (pre) eclampsia) (9). Several features must prompt further diagnostic testing for pheochromocytoma.…”

“…Symptoms may worsen with advancing pregnancy due to an increased pressure on the tumor by the increasing abdominal distension, fetal movements and uterine contractions (9,11). Moreover, estrogens have been suggested to act as a growth factor for adrenal tumors (9,11,13,14).…”

“…The most sensitive tests currently available include plasma and urinary (nor)metanephrines (15). Catecholamine metabolism is generally unaltered during healthy pregnancy, and even in patients with preeclampsia, plasma catecholamine levels are only slightly increased (9). Therefore, in pregnant patients, similar to non-pregnant patients, the most reliable test to confirm or exclude pheochromocytoma is analysis of plasma and/ or 24-h urine (nor)metanephrine concentrations (11,16).…”

“…Results must also be interpreted with caution when patients are already using methyldopa or labetalol as these medications can lead to false-positive results in assays using liquid chromatography with fluorescence detection (7,11). Provocation tests, such as the clonidine suppression test, should be avoided because of low sensitivity and potential serious side effects (9,11). When plasma or urinary (nor)metanephrines are increased, additional imaging studies are needed to confirm diagnosis.…”

“…However, both an excess of catecholamines as well as relative hypotension can reduce uteroplacental circulation as uteroplacental circulation has no autoregulation and is therefore directly affected by changes in maternal blood pressure. High concentrations of catecholamines induce profound vasoconstriction of the maternal uterine arterial circulation, resulting in a compromised uteroplacental circulation, which may lead to intrauterine growth restriction, placental abruption or intrauterine hypoxia (9). Treatment with α-adrenergic receptor blockers can counteract these effects but can result in hypotension compromising uteroplacental circulation as well (6).…”