World Journal of Nuclear Medicine

: 2020  |  Volume : 19  |  Issue : 3  |  Page : 319--320

Reply to follow-up of incidental findings on positron emission tomography

Arvind Krishnamurthy 
 Departments of Surgical Oncology, Cancer Institute (WIA), Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Arvind Krishnamurthy
Department of Surgical Oncology, Cancer Institute (WIA), 38, Sardar Patel Road, Adyar, Chennai - 600 036, Tamil Nadu

How to cite this article:
Krishnamurthy A. Reply to follow-up of incidental findings on positron emission tomography.World J Nucl Med 2020;19:319-320

How to cite this URL:
Krishnamurthy A. Reply to follow-up of incidental findings on positron emission tomography. World J Nucl Med [serial online] 2020 [cited 2020 Dec 2 ];19:319-320
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Full Text

Dear Editor,

I appreciate the keen interest evinced by the authors; Lee et al.[1] toward our work on “PET associated incidental neoplasms of the thyroid (PAIN)” and have noted their experience, seemingly similar to ours,[2] but pertaining to the incidental detection of focal colorectal incidentalomas. The increasing popularity of nuclear imaging, especially the use of positron emission tomography–computed tomography (PET-CT) scans in oncology, has led to a surge in the detection of incidentalomas across various organs. We agree with the authors, the need for guidelines to clearly tease out the incidentalomas harboring malignancies from the ones that are benign or inflammatory. O'Sullivan et al.[3] in an umbrella review of systematic reviews reported that the varying rates of malignancy among incidentalomas across organs, i.e., brain, parotid, and adrenal incidentalomas were reported to be malignant in <5% of the cases, prostatic and colonic incidentalomas were reported malignant in about 10%–20% of cases, while nearly a quarter of the renal, thyroid, and ovarian incidentalomas were reported malignant. Further, the review revealed that breast incidentalomas had the highest percentage (42%) of malignancy.

Given the clinical uncertainty surrounding the ideal management of various incidentalomas and the added anxiety that it creates among the patients, certain authors have encouraged clinicians to discuss with patients the possibility of detecting incidentalomas before ordering any imaging.[4]

There are in fact consensus guidelines for the initial management of incidentalomas across at least eight subsites, including thyroid incidentalomas.[5] Further, there is a white paper which has elegantly described with flow charts, the appropriate approaches to recognizing, reporting, and managing thyroid incidentalomas detected by various imaging modalities including PET-CT scans.[6] The white paper broadly recommends further evaluation of any focal metabolic activity in the thyroid detected on PET-CT scans by thyroid ultrasound and aspiration cytology. Further, the authors recommend no further evaluation of the thyroid incidentalomas in patients with serious comorbidities or limited life expectancy.[6]

It must be noted that some of the above guidelines merely represent the collective wisdom of a few experts/committees and should not be taken as a standard of care for every clinical situation. Nevertheless, some of the above recommendations will indeed help clinicians and patients to make better-informed decisions with regard to the further management of incidentalomas across various organs.

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Conflicts of interest

There are no conflicts of interest.


1Lee JC, Hartnett GF, Hughes BG, Ravi Kumar AS. The segmental distribution and clinical significance of colorectal fluorodeoxyglucose uptake incidentally detected on PET-CT. Nucl Med Commun 2009;30:333-7.
2Kamakshi K, Krishnamurthy A, Karthik V, Vinodkumar P, Kumar RK, Lakshmipathy KM. Positron emission tomography-computed tomography-associated incidental neoplasms of the thyroid gland. World J Nucl Med 2020;19:36-40.
3O'Sullivan JW, Muntinga T, Grigg S, Ioannidis JPA. Prevalence and outcomes of incidental imaging findings: Umbrella review. BMJ 2018;361:k2387.
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