Pheochromocytoma as a rare hypertensive complication rarely associated with pregnancy: Diagnostic difficulties (Review)

Abstract

This review provides a brief clinically relevant review of pheochromocytoma in pregnancy, to raise awareness among doctors in obstetrics and the aim is to serve as the first point of reference when confronted by their presence. Pheochromocytomas are neuroendocrine, catecholamine-secreting tumours. Despite having the highest incidence rate among other hormone-secreting adrenal tumours, they remain rare especially when associated with pregnancy. The non-specific presentation of pheochromocytomas, the difficulties in their diagnosis during pregnancy as well as the high maternal and fetal mortality rates associated with them, present a challenge. Clinical suspicion and meticulous patient history-taking remain the primary lines of defense, while biochemical proof of catecholamine excess (or their metabolites) and imaging-based localisation of the tumour are required for diagnosis. Antenatal diagnosis and complete localisation of the tumour increase the likelihood of successful outcomes for both mother and newborn. Magnetic resonance imaging (MRI) remains the method of choice during pregnancy without excluding the use of ultrasound. Treatment goals should include the avoidance of hypertensive crises while maintaining adequate uteroplacental circulation. The target blood pressure is not strictly defined but is in line with the general guideline addressing chronic hypertension during pregnancy. Antihypertensive medications remain the cornerstone in managing pheochromocytoma. As a first-line, the α-adrenergic, nonselective antagonist phenoxybenzamine is the most frequently used agent, while α1-selective adrenergic antagonists with or without the addition of β- or β1-blockers are also prescribed in certain cases, rendering calcium channel blockers as 'second-choice'. Blood-pressure control of the mother and the well-being of the fetus are determining factors in deciding the time of delivery, which is preferably conducted by Caesarean section. Excision of the tumour(s) remains the final treatment goal. Lifelong biochemical testing is required with or without medical treatment, to address mineralocorticoid or glucocorticoid deficits. Despite ever-improving positive outcome rates, pheochromocytoma associated with pregnancy remains a pathology with high mortality and morbidity rates.

Keywords: catecholamine excess; multiple endocrine neoplasia type 2; neurofibromatosis type 1; pheochromocytoma; pregnancy; secondary hypertension.