PGL4 syndrome in a patient with synchronous paraganglioma-pheochromocytoma.

Pheochromocytoma and paraganglioma (PGL) are rare neuroendocrine tumours, frequently associated with genetic syndromes. We report the case of a man in his 40s with a left anterior neck mass and a history of hypertensive crisis, heavy sweating and constipation. Biochemical tests showed increased plasma and urine normetanephrines. Neck ultrasound suggested left carotid body PGL, but it was mandatory to search for other lesions. Whole-body MIBG failed to show abnormal uptake. Abdominal MRI was suggestive of another PGL, anterior to the right adrenal gland. Abdominal surgery was performed uneventfully under alpha and beta blockers. This intervention proved to be effective, as normetanephrines levels became completely normal after 1 month. Carotid body PGL was successfully excised 4-months later. Genetic study identified a large deletion in exon 1 of the SDHB gene allowing the diagnosis of paraganglioma syndrome type 4 (PGL4). After 19 months of follow-up, he is still on clinical and biochemical remission and will continue life-long surveillance.