Pheochromocytoma and pregnancy: a deceptive connection

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.