Editing Incidental imaging finding (section)

== Adrenal ==
Incidental adrenal masses on imaging are common (0.6 to 1.3% of all abdominal CT). Differential diagnosis include [[adrenal adenoma|adenoma]], [[myelolipoma]], cyst, [[lipoma]], [[pheochromocytoma]], [[adrenal cancer]], [[metastatic cancer]], [[hyperplasia]], and [[tuberculosis]].<ref name="pmid9429862">{{cite journal |author=Cook DM |title=Adrenal mass |journal=Endocrinol. Metab. Clin. North Am. |volume=26 |issue=4 |pages=829–52 | date=December 1997 |pmid=9429862 |doi= 10.1016/s0889-8529(05)70284-x}}</ref>  Some of these lesions are easily identified by radiographic appearance; however, it is often adenoma vs. cancer/metastasis that is most difficult to distinguish.  Thus, clinical guidelines have been developed to aid in diagnosis and decision-making.<ref name="urlwww.aace.com">{{Cite web|url=https://www.aace.com/files/adrenal-guidelines.pdf|title=2009 AACE/AAES Guidelines, Adrenal incidentaloma|access-date=17 September 2014|archive-date=29 August 2017|archive-url=https://web.archive.org/web/20170829230949/https://www.aace.com/files/adrenal-guidelines.pdf|url-status=dead}}</ref> Although adrenal incidentalomas are common, they are not commonly cancerous - less than 1% of all adrenal incidentalomas are malignant.<ref name="O'Sullivan2018"/>

The first considerations are size and radiographic appearance of the mass.  Suspicious adrenal masses or those ≥4&nbsp;cm are recommended for complete removal by adrenalectomy.  Masses <4&nbsp;cm may also be recommended for removal if they are found to be hormonally active, but are otherwise recommended for observation.<ref name="pmid12614096">{{cite journal  |vauthors=Grumbach MM, Biller BM, Braunstein GD, etal |title=Management of the clinically inapparent adrenal mass ("incidentaloma") |journal=Ann. Intern. Med. |volume=138 |issue=5 |pages=424–9 |year=2003 |pmid=12614096 |doi=10.7326/0003-4819-138-5-200303040-00013|s2cid=23454526 }}</ref>  All adrenal masses should receive hormonal evaluation. Hormonal evaluation includes:<ref name="pmid17287480">{{cite journal |author=Young WF |title=Clinical practice. The incidentally discovered adrenal mass |journal=N. Engl. J. Med. |volume=356 |issue=6 |pages=601–10 |year=2007 |pmid=17287480 |doi=10.1056/NEJMcp065470}}</ref>
* 1-mg overnight [[dexamethasone suppression test]]
* 24-hour urinary specimen for measurement of fractionated [[metanephrines]] and [[catecholamines]]
* [[Blood plasma]] [[aldosterone]] concentration and plasma [[renin]] activity, ''if hypertension is present''
On CT scan, benign [[adenoma]]s typically are of low [[radiodensity]] (due to fat content). A radiodensity equal to or below 10 [[Hounsfield units]] (HU) is considered diagnostic of an adenoma.<ref>{{cite web|url=http://www.radiologyassistant.nl/en/p421aee7c659fc/adrenals.html|archive-url=https://web.archive.org/web/20130307065115/http://www.radiologyassistant.nl/en/p421aee7c659fc/adrenals.html|url-status=dead|archive-date=7 March 2013|title=Adrenals - Differentiating benign from malignant|author=Theo Falke and Robin Smithuis|website=Radiology Assistant|access-date=2018-01-02}}</ref> An adenoma also shows rapid [[radiocontrast washout]] (50% or more of the contrast medium washes out at 10 minutes). If the hormonal evaluation is negative and imaging suggests benign lesion, follow up may be considered. Imaging at 6, 12, and 24 months and repeat hormonal evaluation yearly for 4 years is often recommended,<ref name="pmid17287480"/> but there exists controversy about harm/benefit of such screening as there is a high subsequent false-positive rate (about 50:1) and overall low incidence of adrenal carcinoma.<ref name="pmid19439510">{{cite journal |vauthors=Cawood TJ, Hunt PJ, O'Shea D, Cole D, Soule S |title=Recommended evaluation of adrenal incidentalomas is costly, has high false-positive rates and confers a risk of fatal cancer that is similar to the risk of the adrenal lesion becoming malignant; time for a rethink? |journal=Eur. J. Endocrinol. |volume=161 |issue=4 |pages=513–27 | date=October 2009 |pmid=19439510 |doi=10.1530/EJE-09-0234 |doi-access=free }}</ref>