Predictive model of pheochromocytoma based on the imaging features of the adrenal tumours.

The purpose of our study was to develop a predictive model to rule out pheochromocytoma among adrenal tumours, based on unenhanced computed tomography (CT) and/or magnetic resonance imaging (MRI) features. We performed a retrospective multicentre study of 1131 patients presenting with adrenal lesions including 163 subjects with histological confirmation of pheochromocytoma (PHEO), and 968 patients showing no clinical suspicion of pheochromocytoma in whom plasma and/or urinary metanephrines and/or catecholamines were within reference ranges (non-PHEO). We found that tumour size was significantly larger in PHEO than non-PHEO lesions (44.3 ± 33.2 versus 20.6 ± 9.2 mm respectively; P < 0.001). Mean unenhanced CT attenuation was higher in PHEO (52.4 ± 43.1 versus 4.7 ± 17.9HU; P < 0.001). High lipid content in CT was more frequent among non-PHEO (83.6% versus 3.8% respectively; P < 0.001); and this feature alone had 83.6% sensitivity and 96.2% specificity to rule out pheochromocytoma with an area under the receiver operating characteristics curve (AUC-ROC) of 0.899. The combination of high lipid content and tumour size improved the diagnostic accuracy (AUC-ROC 0.961, sensitivity 88.1% and specificity 92.3%). The probability of having a pheochromocytoma was 0.1% for adrenal lesions smaller than 20 mm showing high lipid content in CT. Ninety percent of non-PHEO presented loss of signal in the "out of phase" MRI sequence compared to 39.0% of PHEO (P < 0.001), but the specificity of this feature for the diagnosis of non-PHEO lesions low. In conclusion, our study suggests that sparing biochemical screening for pheochromocytoma might be reasonable in patients with adrenal lesions smaller than 20 mm showing high lipid content in the CT scan, if there are no typical signs and symptoms of pheochromocytoma.

Surgical outcomes in the pheochromocytoma surgery. Results from the PHEO-RISK STUDY.

PURPOSE: To identify presurgical and surgical risk factors for postsurgical complications in the pheochromocytoma surgery. METHODS: A retrospective study of pheochromocytomas submitted to surgery in ten Spanish hospitals between 2011 and 2021. Postoperative complications were classified according to Clavien-Dindo scale. RESULTS: One hundred and sixty-two surgeries (159 patients) were included. Preoperative antihypertensive blockade was performed in 95.1% of the patients, being doxazosin in monotherapy (43.8%) the most frequent regimen. Patients pre-treated with doxazosin required intraoperative hypotensive treatment more frequently (49.4% vs 25.0%, P = 0.003) than patients treated with phenoxybenzamine, but no differences in the rate of intraoperative and postsurgical complications were observed. However, patients treated with phenoxybenzamine had a longer hospital stay (12.2 ± 11.16 vs 6.2 ± 6.82, P < 0.001) than those treated with doxazosin. Hypertension resolution was observed in 78.7% and biochemical cure in 96.6% of the patients. Thirty-one patients (19.1%) had postsurgical complications. Prolonged hypotension was the most common, in 9.9% (n = 16), followed by hypoglycaemia in six patients and acute renal failure in four patients. 13.0% of complications had a score ≥3 in the Clavien-Dindo scale. Postsurgical complications were more common in patients with diabetes, cerebrovascular disease, higher plasma glucose levels, higher urinary free metanephrine and norepinephrine, and with pheochromocytomas larger than 5 cm. CONCLUSION: Preoperative medical treatment and postsurgical monitoring of pheochromocytoma should be especially careful in patients with diabetes, cerebrovascular disease, higher levels of plasma glucose and urine free metanephrine and norepinephrine, and with pheochromocytomas >5 cm, due to the higher risk of postsurgical complications.

Performance of plasma free metanephrines in diagnosis of pheochromocytomas and paragangliomas in the population of Asturias. / Rendimiento de las metanefrinas libres plasmáticas en el diagnóstico de los feocromocitomas y paragangliomas en la población asturiana.

INTRODUCTION: Pheochromocytoma and paraganglioma are uncommon tumors whose best known symptoms include high blood pressure, palpitations, headache, and sweating. Clinical identification is not easy, however, and requires biochemical tests that allow for early diagnosis, including measurement of metanephrines levels. The aim of this study was to assess the diagnostic performance of plasma free metanephrines (PMETs) and to verify the transferability of the reference values used. METHODS: PMETs levels were measured by liquid chromatography coupled to tandem mass spectrometry. Other biochemical tests evaluated (plasma catecholamine, urine metanephrine, catecholamine and vanilmandelic acid levels) were performed by liquid chromatography with electrochemical detection. Requests of these tests from 01/09/2015 to 31/10/2017 were reviewed, and both the reference values (document EP28-A3c) and the parameters of biological variation (Fraser method) for PMETs were estimated. RESULTS: The study sample consisted of 1,279 patients (61.3% females) aged 0-90 years, including 19 with pheochromocytoma/paraganglioma. Tests requested included: PMETs (n=662), catecholamines (n=589), metanephrines (n=586), and vanilmandelic acid (n=513) in urine, and plasma catecholamines (n=228). Tests with higher sensitivity were urinary fractionated metanephrines (91.7%) and PMETs (82.4%). When performance was compared in patients with both tests (n=243), they detected the same number of tumors (90.9%), but PMETs showed greater specificity (93.5% vs 88.8%). Plasma normetanephrine levels showed a significant association with age (rho=0.19, P<.0001). CONCLUSION: PMETs and urinary fractionated metanephrines are the biochemical tests with better performance in diagnosis of pheochromocytomas/paragangliomas.