Pheochromocytoma in pregnancy: a review of the Japanese literature.

We review the 35 cases with pheochromocytoma associated with pregnancy including our own 3 cases in the Japanese literature from 1958 to 1993. In a total of 35 cases, the overall maternal mortality rate was 11% and the fetal loss 22%. Recently, after 1981, the maternal mortality rate and the fetal loss were significantly reduced to one patient (6%). Although antepartum diagnosis of pheochromocytoma was made in only 32% of the patients, maternal mortality was reduced to zero and fetal loss to 18%. An initial diagnosis of toxemia of pregnancy was made in 17 patients (49%) and of pheochromocytoma in 10 patients (29%). A diagnosis of pheochromocytoma was made before delivery in 11 patients (31%), after delivery in 22 patients (63%), at autopsy in one patient (3%), and unknown in one patient (3%). The symptoms mostly suggestive of pheochromocytoma were paroxysmal hypertension in 27 (77%) of the 35 patients. The clinical symptoms generally appeared in the third trimester in 23 patients (66%). Pheochromocytoma is a rare disease, but a high index of clinical suspicion must be kept in mind and pheochromocytoma must be listed in the differential diagnosis of hypertension associated with pregnancy. Recently, abdominal ultrasound study and MR imaging can be used to localize the tumor during the antepartum period. Once the diagnosis is confirmed, alpha-blockade is essential and beta-blockade may be required. In the first and second trimesters, tumor resection has a good fetal outcome; in later pregnancy, delivery by elective caesarean section followed by tumor resection is recommended.