Thyroid incidentaloma

1. INCIDENTAL THYROID
NODULE
Prepared by Dr. Florence Keli
University of Nairobi, Kenya

2. INCIDENTAL THYROID NODULES
Incidental thyroid nodule also referred to as thyroid incidentaloma, is an asymptomatic nodule discovered during imaging or surgery for
diseases other than thyroid (Chaikhoutdinov et al 2014) and (Krzysztof et al 2018). There is a number of incidentalomas found at autopsy.
Controversy reigns in their mode of management and investigations and predictors of being malignant (Abu‐Ghanem et al 2016).
In a retrospective study by Abu‐Ghanem and team, 60% incidentalomas were found at imaging, this is much higher than other studies.
Other studies report an incidence of 13-19% at imaging as reported by Abu-Ghanem et al.
Abu‐Ghanem and team point out that their discovery, makes patients subject to
 Numerous imaging studies that do not have clear clinical data or direction
 Unnecessary follow up and anxiety to patients
 Surgery of benign nodules
Their discovery results to
 Increased prevalence of incidentalomas
 General increase in the number of all cancers
 Dilemma in managing them
 Increased cost of medical care(Russ et al 2014)
Chaikhoutdinov , I.,Mitzner, R.,Goldenberg D, (2014). ‘Incidental Thyroid Nodules: Incidence, Evaluation, and Outcome’. Available at https://doi-
org.ergo.southwales.ac.uk/10.1177%2F0194599814524705 (Accessed November 23, 2020)
Krzysztof., Dorota, D.,Marcin, Z., Bartlomiej, K., et al. (2018). ‘Thyroid incidentaloma as a "PAIN" phenomenon- does it always require surgery?’. Medicine, 9(49) pp e13339.Available at
https://doi.org/10.1097/MD.0000000000013339. (Accessed December 2, 2020)
Abu‐Ghanem, S., Cohen, O., Lazutkin, A., Abu‐Ghanem, Y., Fliss, D.M. and Yehuda, M. (2016), ‘Evaluation of clinical presentation and referral indications for ultrasound‐guided fine‐needle aspiration
biopsy of the thyroid as possible predictors of thyroid cancer’. Head Neck, 38: pp (E991-E995). Available at https://doi-org.ergo.southwales.ac.uk/10.1002/hed.24143 Accessed November 24, 2020
Russ, G., Leboulleux, S., Leenhardt, L.,Hegedüs, L. (2014). ‘Thyroid incidentalomas: epidemiology, risk stratification with ultrasound and workup’. European thyroid journal, 3(3),pp( 154–

3. EPIDEMIOLOGY
Rates of detection of TI based on imaging and clinical event (Jin et al 2012)
High resolution ultrasound 67%
CT and MRI 16%
Carotid Doppler ultrasound 9.4%
PET scan 2-3%. 14-50% rate of picking these lesions
At Parathyroidectomy 40%
Autopsy 50-60%
Jin,J., McHenry C. R..,(2012). ‘Thyroid incidentaloma’ Best Practice & Research Clinical
Endocrinology & Metabolism, 26,(1) pp 83-96, Available at
https://doi.org/10.1016/j.beem.2011.06.004. Accessed December 3, 2020.
The prevalence of thyroid incidentalomas (TI) is 5 % in the general population (Russ et al 2014)
The incidence per imaging modality is as below as indicated by Russ and his team is
Ultra sound rate of picking of TI is as follows, older ultrasounds 10-36%, newer improved
ultrasound imaging 67% , recent prospective studies counting thyroid nodules < 10mm, 70-83%
CT/MRI finds 15% while Positon Emission scan picks 2% .
The incidence increases with age at 50 years its 30-40%.
The incidence of TI, as per Krzysztof and team by various imaging modalities is
PET scan 1% -4.3%, this have 50% chance of being malignant, leading to the talk about Pet scan
Associated Incidentaloma Neoplasia of thyroid the ‘PAIN’ phenomenon
Ultrasound up to 50%
Russ, G., Leboulleux, S., Leenhardt, L.,Hegedüs, L. (2014). ‘Thyroid incidentalomas:
epidemiology, risk stratification with ultrasound and workup’. European thyroid journal, 3(3),pp(
154–163).Available at https://doi.org/10.1159/000365289 (Accessed November 29, 2020)
Krzysztof, K., Dorota,D., Marcin,Z. Bartlomiej, K. ,Michal, A., Sutkowsk, K., Beata, W., Valerio,
D‘. (2018). Thyroid incidentaloma as a "PAIN" phenomenon- does it always require surgery?.
Medicine, 97(49), (pp e13339). Available at https://doi.org/10.1097/MD.0000000000013339.
(Accessed December 2, 2020)
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Rate by imaging or procedure
Series1 Series2 Series3

4. FINDING A TI
Modality of discovery of thyroid incidentaloma
Investigation / procedure that of
discovery of TI
Description
Ultrasound This is at neck ultra sound for
abnormal parathyroid glands, neck
masses, enlarged nodes, carotid
artery lesions, central catheterization
, medical checkup for normal
individuals
CT, MRI Head and neck CT scan for lung
disease , CT and/MRI of neck and
spine, CT angiography for carotid
artery, trauma and pulmonary
embolism
PET scan At assessment of patients with
cancer
Surgery Para thyroidectomy, carotid
/cervical/esophageal and exploration
of a traumatized neck and chest
Autopsy Autopsy
Limitation in discovering a TI
Artefacts may be confused for thyroid incidentaloma (TI)
A TI may be obscured
Small TI may be missed
The thyroid may be ectopically placed
Features that allude to malignancy in TI
 Age <20 > 60yrs, male sex, past radiation of head, neck or body and breast ,
family history of thyroid cancer/ thyroid cancer syndromes , history of
hoarseness of voice, dysphagia, chocking episodes, it should be noted that
neck pain is an indication of thyroiditis
 Lymph node enlargement, firm fixed solid nodes, displaced trachea, paralysis
of vocal cords confirmed by laryngoscopy.
Reference
Jin,J., McHenry C. R..,(2012). ‘Thyroid incidentaloma’ Best Practice & Research Clinical
Endocrinology & Metabolism, 26,(1) pp 83-96, Available at
https://doi.org/10.1016/j.beem.2011.06.004. Accessed December 3, 2020.

5. INVESTIGATIONS
A multifaceted approach in making a definitive diagnosis of a thyroid incidentaloma is key (Jo et al 2009) and (Jin et al
2012)
Investigations include
Thyroid ultrasound. Its able to pick nodules that are as small as 3mm
Fine needle aspiration guided by ultrasound , cytology and immunohistochemistry
FNA is indicated for suspicious nodules < 1cm and all nodules > 1cm ( Jo et al 2009)
TSH, fT4, fT3, antibodies to Tg TPO when is high TSH, TRABs antibodies in low THS
CT scan of the neck to assess involvement of the trachea
MRI of the thyroid to assess involvement of structures adjacent to the thyroid and ectopic thyroid gland
Jo, Y.S., Huang, S., Kim, Y.‐J., Lee, I.‐S., Kim, S.‐S., Kim, J.‐R., Oh, T., Moon, Y., An, S., Ro, H.‐k., Kim, J.‐M., Shong, M. (2009), ‘Diagnostic value of pyrosequencing
for the BRAFV600E mutation in ultrasound‐guided fine‐needle aspiration biopsy samples of thyroid incidentalomas’. Clinical Endocrinology, 70(1) pp 139-144. https://doi-
org.ergo.southwales.ac.uk/10.1111/j.1365-2265.2008.03293.x (Accessed December 2, 2020)
Jinn., McHenry C. R..,(2012). ‘Thyroid incidentaloma’ Best Practice & Research Clinical Endocrinology & Metabolism, 26,(1) pp 83-96, Available at https://doi.org/10.1016/j.beem.2011.06.004. Accessed December 3, 2020.

6. RED FLAGS AND FEATURES
SUGGESTIVE OF MALIGNANCY
Jin and team point out following features as an indication of malignancy in a TI at ultrasound, and
FDG PET scan
Tiny calcium deposits appearing like specks
Borders that are not smooth
The so described ‘taller than wide’ appearance of the node
Hypo echoic nodules
Incomplete halo
Increased vascularization, focal or unilateral uptake at FDG PET scan
Incidentalomas found at PET scan
Reference
Jin,J., McHenry C. R..,(2012). ‘Thyroid incidentaloma’ Best Practice & Research Clinical Endocrinology & Metabolism, 26,(1) pp 83-96, Available at https://doi.org/10.1016/j.beem.2011.06.004. Accessed
December 3, 2020.

7. LESIONS THAN BE FOUND IN
THYROID INCIDENTALOMAS
A TI may be benign, a cystic nodule, or a nodule causing hyper/hypo thyroidism
Malignant lesions include
 Papillary carcinoma
 Follicular carcinoma
 Well differentiated thyroid cancer
 Metastasis to the thyroid , commonly from the kidney, breast, lung, and esophagus
15-30% cytology reports are indeterminate of the thyroid lesion in the thyroid incidentaloma (Jo et al 2009)
When the cytology report is indeterminate repeat FNAC guided by ultrasound
Jo, Y.S., Huang, S., Kim, Y.‐J., Lee, I.‐S., Kim, S.‐S., Kim, J.‐R., Oh, T., Moon, Y., An, S., Ro, H.‐k., Kim, J.‐M. and Shong, M. (2009), ‘Diagnostic value of
pyrosequencing for the BRAFV600E mutation in ultrasound‐guided fine‐needle aspiration biopsy samples of thyroid incidentalomas’. Clinical Endocrinology,
70(1) pp 139-144. https://doi-org.ergo.southwales.ac.uk/10.1111/j.1365-2265.2008.03293.x

8. MICRO CALCIFICATION OF AN INCIDENTALOMA ON ULTRASOUND IN THE (LEFT
PANEL) FOUND AT MRI OF NECK (RIGHT PANEL). THE TWO IMAGES WERE ADOPTED
FROM WORK DONE BY JINN AND TEAM.
REFERENCE
JINN., MCHENRY C. R..,(2012). ‘THYROID INCIDENTALOMA’ BEST PRACTICE & RESEARCH CLINICAL ENDOCRINOLOGY & METABOLISM, 26,(1) PP 83-96,
AVAILABLE AT HTTPS://DOI.ORG/10.1016/J.BEEM.2011.06.004. ACCESS ED DECEMBER 3, 2020.
A thyroid incidentaloma may be missed at clinical examination
because of the size, location, short and/obese neck, the thyroid may
be prominent in lean persons (Singh et al 2020). Clinical exam is
38% sensitive in locating a thyroid incidentaloma.
Singh, S., Singh, A., Khanna, A. K. (2012). ‘Thyroid incidentaloma’. Indian journal of surgical
oncology, 3(3), pp(173–181)). Available at https://doi.org/10.1007/s13193-011-0098-y (Accessed 29th
November 2020)
This MRI was done to check for the cause of neck pain. The thyroid
incidentaloma is pointed with a white arrow (Jinn et al 2012)

9. TREATMENT
State the cytology finding by Thy or Bethesda criteria
The management of a TI should be left at the discretion of the team of experts
Patients life expectancy should be considered always at management
Tumors with a low malignancy risk can be monitored with TSH and ultrasound
yearly
The following challenges remain about the management of thyroid incidentaloma
 Identification of malignant lesions that could be aggressive
 The state of not yet approved use of genetic testing
Reference
Jin,J., McHenry C. R..,(2012). ‘Thyroid incidentaloma’ Best Practice & Research Clinical Endocrinology & Metabolism, 26,(1) pp 83-96, Available at
https://doi.org/10.1016/j.beem.2011.06.004. Accessed December 3, 2020.

10. MANAGEMENT OF TI
THIS FLOW CHART WAS MODIFIED FROM WORK DONE BY JIN ET AL
REFERENCE
JIN,J., MCHENRY C. R..,(2012). ‘THYROID INCIDENTALOMA’ BEST PRACTICE & RESEARCH CLINICAL ENDOCRINOLOGY & METABOLISM, 26,(1) PP 83-
96, AVAILABLE AT HTTPS://DOI.ORG/10.1016/J.BEEM.2011.06.004. ACCESSED DECEMBER 3, 2020
Thyroid
incidentaloma
What is the TSH?
Low TSH
Scintigraphy,
fT4,T3
Low TSH, Normal
uptake , high fT4
high T3
Thyroid ultrasound
and Fine needle
aspirate for
cytology
Red flags in
ultrasound and or
cytology
Indeterminate
results repeat
ultrasound guided
FNAC
Refer for
multifaceted
management
High RAI uptake,
low TSH, High
fT4 high T3
Manage
hyperthyroidism
High TSH
Antibodies to TPO,
Tg fT4,
High TSH, Low
fT4 positive
autoantibodies
Manage
Hashimoto’s
disease
High TSH, low
fT4, no antibodies
Thyroid ultrasound
and fine needle
aspirate for
cytology
Red flags in
ultrasound and or
cytology
Refer for multi-
disciplinary
management
Indeterminate
results repeat
ultrasound guided
FNAC
Normal TSH ,
ultrasound
If ultrasound shows
red flags get
FNAC ultrasound
guided
Cytology indicates
malignancy refer
to experts
Indeterminate
reports, repeat
FNAC