CT Characteristics of Pheochromocytoma: Relevance for the Evaluation of Adrenal Incidentaloma.
Van Hemert, Janna AW
Kerstens, Michiel N
Hartman, Robert P
Challis, Benjamin G
Young, William F
Timmers, Henri JLM
The Journal of clinical endocrinology and metabolism
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Canu, L., Van Hemert, J. A., Kerstens, M. N., Hartman, R. P., Khanna, A., Kraljevic, I., Kastelan, D., et al. (2019). CT Characteristics of Pheochromocytoma: Relevance for the Evaluation of Adrenal Incidentaloma.. The Journal of clinical endocrinology and metabolism, 104 (2), 312-318. https://doi.org/10.1210/jc.2018-01532
Background: Up to 7% of all adrenal incidentalomas (AIs) are pheochromocytomas (PCCs). In the evaluation of AI, it is generally recommended that PCC be excluded by measurement of plasma-free or 24-hour urinary fractionated metanephrines. However, recent studies suggest that biochemical exclusion of PCC not be performed for lesions with CT characteristics of an adrenocortical adenoma (ACA). Aim: To determine the proportion of PCCs with ACA-like attenuation or contrast washout on CT. Methods: For this multicenter retrospective study, two central investigators independently analyzed the CT reports of 533 patients with 548 histologically confirmed PCCs. Data on tumor size, unenhanced Hounsfield units (HU), absolute percentage washout (APW), and relative percentage washout (RPW) were collected in addition to clinical parameters. Results: Among the 376 PCCs for which unenhanced attenuation data were available, 374 had an attenuation of \textgreater10 HU (99.5%). In the two exceptions (0.5%), unenhanced attenuation was exactly 10 HU, which lies just within the range of ≤10 HU that would suggest a diagnosis of ACA. Of 76 PCCs with unenhanced HU \textgreater 10 and available washout data, 22 (28.9%) had a high APW and/or RPW, suggestive of ACA. Conclusion: Based on the lack of PCCs with an unenhanced attenuation of \textless10 HU and the low proportion (0.5%) of PCCs with an attenuation of 10 HU, it seems reasonable to abstain from biochemical testing for PCC in AIs with an unenhanced attenuation of ≤10 HU. The assessment of contrast washout, however, is unreliable for ruling out PCC.
Humans, Pheochromocytoma, Adrenal Gland Neoplasms, Contrast Media, Diagnosis, Differential, Tomography, X-Ray Computed, Retrospective Studies, Adult, Aged, Middle Aged, Female, Male
External DOI: https://doi.org/10.1210/jc.2018-01532
This record's URL: https://www.repository.cam.ac.uk/handle/1810/291763
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