Systematic genetic screening in a prospective group of Danish patients with pheochromocytoma

Recent guidelines recommend consideration of genetic screening in all newly diagnosed patients with pheochromocytoma. Patients diagnosed with pheochromocytoma in the Region of Southern Denmark during 2006-2013 without previously recognized monogenetic etiology were offered genetic screening for mutations in the VHL, RET, SDHB, SDHC, and SDHD genes. A total of 41 patients were included, and genetic data were available in 35. In four of the 35 patients, a pathogenic variant was identified prior to the diagnosis of pheochromocytoma (von Hippel-Lindau disease, n=2; neurofibromatosis type 1, n=2). The patients carrying a genetic mutation were all younger than 45 years at time of diagnosis of pheochromocytoma, two patients presented with bilateral tumors, and one patient had a positive family history of pheochromocytoma. Genetic screening of the remaining 31 patients did not identify any mutations. The sporadic cases had a median age of 58 years (range 33-80 years). Three of 31 sporadic cases (ages 60, 69, and 76 years at time of diagnosis) presented with bilateral adrenal tumors, one patient had multiple adrenal tumors in both adrenal glands, and no patients had a positive family history of pheochromocytoma. Of the 31 patients, 24 (68.6%) were diagnosed with pheochromocytoma due to evaluation of an adrenal incidentaloma. In conclusion, monogenetic etiology was identified in four of 35 (11.4%) patients diagnosed with pheochromocytoma.