ADHD Diagnosis May Actually Be a Rare Tumor, Say NIH Researchers

Pheochromocytoma and paraganglioma (PHEO/PGL), rare tumors of the peripheral nervous system that secrete stimulants that can cause symptoms of attention deficit hyperactivity disorder (ADHD), can lead to an inaccurate diagnosis and subsequently harmful treatment in pediatric patients, according to a new study conducted by researchers at the National Institutes of Health (NIH).

The authors evaluated 43 patients, not more than 18 years of age, who were evaluated at NIH between January 2006 and May 2014. The authors documented the patient’s prior diagnosis of ADHD and treatment with stimulant medications. Additionally, symptoms, levels of catecholamine and metanephrine, tumor characteristics, and genetic analyses for syndromes associated with PHEO/PGL were evaluated.

When compared with the general pediatric population (7.2%), the authors found that patients with PHEO/PGL were much more likely (9 of 43, or 21%) to be diagnosed with ADHD, before the presence of their tumor was known. These 9 children initially presented with behavioral symptoms including hyperactivity, difficulty concentrating, and poor school performance, and were diagnosed with ADHD. Four patients were subsequently treated with amphetamine and dextroamphetamine or methylphenidate, and 1 patient was admitted for a 2-week behavior intervention for oppositional/defiant disorder.

Median age at the time of diagnosis of PHEO/PGL was 14 (range 6.6-15), and the authors also report that 7 of the 9 patients tested positive for mutations in genes associated with PHEO/PGL.

Treatment with amphetamine, dextroamphetamine, and/or methylphenidate, could have potentially exacerbated an adrenergic crisis in these children. In addition, 4 patients exhibited hypertension at the initial diagnosis of their PHEO/PGL, which could have been a result of medications used to treat ADHD.

Surgical removal of the tumor could reverse symptoms of ADHD in 3 of the 9 children, the study found. Based on their findings, the authors advice that when hypertension and symptoms of ADHD are diagnosed in young patients, they should be evaluated to rule out the presence of PHEO/PGL.

Reference

Batsis M, et al. Attention deficit hyperactivity disorder in pediatric patients with pheochromocytoma and paraganglioma [published online May 12, 2016]. Horm Metab Res. doi:10.1055/s-0042-106725.