Incidental imaging finding
In medical or research imaging, an incidental imaging finding (also called an incidentaloma) is an unanticipated finding which is not related to the original diagnostic inquiry. As with other types of incidental medical findings, they may represent a diagnostic, ethical, and philosophical dilemma because their significance is unclear. While some coincidental findings may lead to beneficial diagnoses, others may lead to overdiagnosis that results in unnecessary testing and treatment, sometimes called the "cascade effect".[1]
Incidental findings are common in imaging. For instance, around 1 in every 3 cardiac
As the use of medical imaging increases, the number of incidental findings also increases.[citation needed]
Adrenal
Incidental adrenal masses on imaging are common (0.6 to 1.3% of all abdominal CT). Differential diagnosis include
The first considerations are size and radiographic appearance of the mass. Suspicious adrenal masses or those ≥4 cm are recommended for complete removal by adrenalectomy. Masses <4 cm may also be recommended for removal if they are found to be hormonally active, but are otherwise recommended for observation.[5] All adrenal masses should receive hormonal evaluation. Hormonal evaluation includes:[6]
- 1-mg overnight dexamethasone suppression test
- 24-hour urinary specimen for measurement of fractionated catecholamines
- Blood plasma aldosterone concentration and plasma renin activity, if hypertension is present
On CT scan, benign
Brain
Thyroid and parathyroid
Incidental thyroid masses may be found in 9% of patients undergoing bilateral carotid duplex ultrasonography.[12]
Some experts
- solid hypoechoic appearance
- irregular or blurred margins
- intranodular vascular spots or pattern
- microcalcifications
Incidental
Features | Workup |
---|---|
|
Very likely ultrasonography |
Multiple nodules | Likely ultrasonography |
Solitary nodule in person younger than 35 years old |
|
Solitary nodule in person at least 35 years old |
|
Pulmonary
Studies of whole body screening
Kidney
Most renal cell carcinomas are now found incidentally.[19] Tumors less than 3 cm in diameter less frequently have aggressive histology.[20]
A CT scan is the first choice modality for workup of solid masses in the kidneys. Nevertheless, hemorrhagic cysts can resemble renal cell carcinomas on CT, but they are easily distinguished with Doppler ultrasonography (Doppler US). In renal cell carcinomas, Doppler US often shows vessels with high velocities caused by neovascularization and arteriovenous shunting. Some renal cell carcinomas are hypovascular and not distinguishable with Doppler US. Therefore, renal tumors without a Doppler signal, which are not obvious simple cysts on US and CT, should be further investigated with contrast-enhanced ultrasound, as this is more sensitive than both Doppler US and CT for the detection of hypovascular tumors.[21]
Spinal
The increasing use of MRI, often during diagnostic work-up for back or lower extremity pain, has led to a significant increase in the number of incidental findings that are most often clinically inconsequential. The most common include:[22]
- vertebral hemangioma
- fibrolipoma (a lipoma with fibrous areas)
- Tarlov cyst
Sometimes normally asymptomatic findings can present with symptoms and these cases when identified cannot then be considered as incidentalomas.[citation needed]
Criticism
The concept of the "incidentaloma" has been criticized, as such lesions do not have much in common other than the history of an incidental identification and the assumption that they are clinically inert. It has been proposed just to say that such lesions have been "incidentally found."[23] The underlying pathology shows no unifying histological concept.[citation needed]
References
- PMID 20335439.
- ^ PMID 29914908.
- PMID 9429862.
- ^ "2009 AACE/AAES Guidelines, Adrenal incidentaloma" (PDF). Archived from the original (PDF) on 29 August 2017. Retrieved 17 September 2014.
- S2CID 23454526.
- ^ PMID 17287480.
- ^ Theo Falke and Robin Smithuis. "Adrenals - Differentiating benign from malignant". Radiology Assistant. Retrieved 2 January 2018.
- PMID 19439510.
- S2CID 23833253.
- PMID 9429857.
- ^ Snyder (2021). "Causes, presentation, and evaluation of sellar masses".
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(help) - ^ PMID 16230549.
- S2CID 41308483.
- PMID 17056928.
- PMID 11994321.
- ^ Jenny Hoang (5 November 2013). "Reporting of incidental thyroid nodules on CT and MRI". Radiopaedia., citing:
- Hoang, Jenny K.; Langer, Jill E.; Middleton, William D.; Wu, Carol C.; Hammers, Lynwood W.; Cronan, John J.; Tessler, Franklin N.; Grant, Edward G.; Berland, Lincoln L. (2015). "Managing Incidental Thyroid Nodules Detected on Imaging: White Paper of the ACR Incidental Thyroid Findings Committee". Journal of the American College of Radiology. 12 (2): 143–150. PMID 25456025.
- Hoang, Jenny K.; Langer, Jill E.; Middleton, William D.; Wu, Carol C.; Hammers, Lynwood W.; Cronan, John J.; Tessler, Franklin N.; Grant, Edward G.; Berland, Lincoln L. (2015). "Managing Incidental Thyroid Nodules Detected on Imaging: White Paper of the ACR Incidental Thyroid Findings Committee". Journal of the American College of Radiology. 12 (2): 143–150.
- PMID 16170016.
- PMID 17873164.
- PMID 11343669.
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- PMID 12455801.