OBJECTIVE: To study the performance of measuring plasma fractionated free metanephrines by enzyme immunoassay (EIA) in the diagnosis of pheochromocytoma and catecholamine-secreting paraganglioma. METHODS: Consecutive patients attending the endocrine clinic at King Edward Memorial Hospital, Mumbai, India, for suspicion of catecholamine-secreting tumors were included. Plasma fractionated free metanephrines were measured by EIA, and computed tomography of the neck, chest, abdomen, and pelvis was performed. Those with tumor identified by imaging underwent 131I m-iodobenzylguanidine scintigraphy. All patients with adrenal masses larger than 3 cm and patients with secretory tumors, irrespective of their size, underwent tumor excision. The rest were followed up for 6 to 12 months. RESULTS: One hundred patients with a clinical suspicion of pheochromocytoma or paraganglioma were included. Plasma free normetanephrine alone had a sensitivity of 94.1% (cutoff: 180 ng/mL), while plasma free metanephrine had a sensitivity of 14.7% (cutoff: 90 pg/mL). Both had 96.9% specificity. When combined (either test positive), the sensitivity was 94.1% with a specificity of 93.75%. Thirty-four patients had a histopathologically proven pheochromocytoma or paraganglioma. It was concluded that 66 patients did not harbor a pheochromocytoma or catecholamine-secreting paraganglioma. CONCLUSION: Plasma fractionated free metanephrines measured by EIA have good sensitivity and specificity in the diagnosis of pheochromocytoma and catecholamine-secreting paraganglioma.
OBJECTIVE: To study the performance of measuring plasma fractionated free metanephrines by enzyme immunoassay (EIA) in the diagnosis of pheochromocytoma and catecholamine-secreting paraganglioma. METHODS: Consecutive patients attending the endocrine clinic at King Edward Memorial Hospital, Mumbai, India, for suspicion of catecholamine-secreting tumors were included. Plasma fractionated free metanephrines were measured by EIA, and computed tomography of the neck, chest, abdomen, and pelvis was performed. Those with tumor identified by imaging underwent 131I m-iodobenzylguanidine scintigraphy. All patients with adrenal masses larger than 3 cm and patients with secretory tumors, irrespective of their size, underwent tumor excision. The rest were followed up for 6 to 12 months. RESULTS: One hundred patients with a clinical suspicion of pheochromocytoma or paraganglioma were included. Plasma free normetanephrine alone had a sensitivity of 94.1% (cutoff: 180 ng/mL), while plasma free metanephrine had a sensitivity of 14.7% (cutoff: 90 pg/mL). Both had 96.9% specificity. When combined (either test positive), the sensitivity was 94.1% with a specificity of 93.75%. Thirty-four patients had a histopathologically proven pheochromocytoma or paraganglioma. It was concluded that 66 patients did not harbor a pheochromocytoma or catecholamine-secreting paraganglioma. CONCLUSION: Plasma fractionated free metanephrines measured by EIA have good sensitivity and specificity in the diagnosis of pheochromocytoma and catecholamine-secreting paraganglioma.
Authors: Roland Därr; Matthias Kuhn; Christoph Bode; Stefan R Bornstein; Karel Pacak; Jacques W M Lenders; Graeme Eisenhofer Journal: Endocrine Date: 2017-04-12 Impact factor: 3.633
Authors: Tomás P Griffin; Delia Bogdanet; Patrick Navin; Grace Callagy; Paula M O'Shea; Marcia Bell Journal: Ir J Med Sci Date: 2018-02-19 Impact factor: 1.568