Nodules Approach

Barry Sacks MD Ashley Davidoff MD

The Common vein Copyright 2010


Clinical problem and Statistics

Nodules in 7-10 % of Population by Palpation

Incidence Much Higher By Ultrasound (40-50% – >60%)

Of all nodules 95% will be benign

Of all malignant lesions 95% will be papillary carcinoma which is usually an indolent disease.

 Thus small % of malignant tumors have bad prognosis

Basic Classification of Thyroid Nodules
The diagram illustrates a range of nodules that can affect the thyroid. Based on thyroid function tests and sometimes with the aid of a nuclear scan the nodules are divided into functioning or non-functioning. If they are hyperfunctioning they are called “toxic” (bright red nodules) and if not then they are called “non-toxic”. When they are hyperfunctioning they suppress the function of the normal thyroid and hence the normal thyroid in these cases are grayed out. Morphologically they may be single or multiple, large or small. When they cause thyroid enlargement they are called a goiter. From a pathological perspective nodules may be benign or malignant. The benign nodules have a wide ranges of microscopic findings. The primary malignant lesions include follicular carcinoma, papillary carcinoma and medullary carcinoma.
Courtesy Ashley Davidoff MD Copyright 2010 93852e07h01a04L.8s

Characterization of Nodules
The multinodular goiter in this diagram is a combination of simple cysts (yellow), complex cysts (light green) and solid nodules (dark green). Characterisation of complex and solid lesions is best first evaluated by
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Macrofollicular adenoma (simple colloid)

Microfollicular adenoma (fetal)

Embryonal adenoma (trabecular)

Hürthle cell adenoma (oxyphilic, oncocytic)

Atypical adenoma

Adenoma with papillae

Signet-ring adenoma


Papillary (75 percent)

Follicular (10 percent)

Medullary (5 to 10 percent)

Anaplastic (5 percent)


Thyroid lymphoma (5 percent)


Simple cyst

Cystic/solid tumors (hemorrhagic, necrotic)

Colloid Nodule

Dominant nodule in a multinodular goiter


Inflammatory thyroid disorders

Subacute thyroiditis

Chronic lymphocytic thyroiditis

Granulomatous disease

Developmental abnormalities


Rare unilateral lobe agenesis

Challenge Is Which Require Workup

Criteria for the Imaging and Follow-up of Thyroid Nodules


Age And Sex Of Patient

>1-1.5 Cm

Single Vs Multiple

Firm To Palpation

Family History

Radiation Exposure

Imaging Considerations

Ultrasound very good at extremes

Macrofollicular and mixed macro/micro on one extreme

Obvious neoplasms especially papillary carcinoma on the other

heterogenous lesions usually indeterminate

Should biopsy the most hypoechoic region

Should biopsy all hypoechoic lesions even < 1cm, especially when margins irregular

Microcalcifications with comet tail or ring down less concerning

Other microcalcifications more concerning

Benign features

Larger Nodules More Often Benign

Smooth Round or Oval

Texture similar to normal thyroid

Homogeneous lesion

Cystic Changes

Hypoechoic thin halo

Vascular Pattern Usually hypovascualr and peripheral – though papillary are hypovascular

Peripheral egg shell calcification

Malignant features

Malignancies Can Be Small

Irregular shape

Hypoechoic or heterogeneous

Not usually cystic

Irregular margins

thick halo or irregular halo


Extremely Vascular



Ring Down or Comet Tail Sign – Benign
The 80 year old male presents with an asymptomatic multinodular goiter, consisting many nodules of varying size and echogenicity.
A microcalcification with ring down artifact is seen overlaid in teal blue. Other microcalcifications are probably present (overlaid in white). The multiple nodules that are not border forming are within the confines of the parenchyma and do not alter the shape of the gland. The right lobe of the thyroid measures about 4.5 cms in sagittal A-P dimension, and 1.5cms in the transverse plane. The gland is therefore not enlarged These findings are consistent with a non toxic multinodular thyroid gland, and not truly a goiter since the gland is not enlarged. The ringdown or comet tail artifact characteristic of small calcifications is exemplified in this image and is usually a sign of benign calcification. On the other hand the fine echogenicities without ring down artifact are more concerning.
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Malignant Nodule
Large Irregular Halo, Microcalcifications
A large nodule in the thyroid occupies almost the entire right lobe (a). The nodule measures 2.9cms by 1.5cms. The gland is not enlarged and measures 3.5cms (craniocaudad), by 1.8cms (A-P) by 2.4cms (transverse). The nodule is almost isoechoic with normal thyroid but shows internal irregular areas of hypoechogenicity, regions of isoechogenicity, as well as microcalcifications (white arrows (c). There is irregularity of the border at the posterior aspect of the nodule green arrow a). The halo shows irregular borders in this region as well. Internal vascularity is minimal (d). The irregular surface is concerning for a malignant processes. The diagnosis in this patient was papillary carcinoma
Courtesy Ashley Davidoff MD Copyright 2010 74909c02L.8

Biopsy from the opposite side

Medial to lateral

25g needles – no aspiration Use capillary vacuum of the 25gauge needle

4 passes into different regions

smear slides and immediately fix

inject remainder into cytolyte

if ? Lymphoma – send flow cytometry

Features to be evaluated by ultrasound

Overall gland size for each lobe

Sagital images for length and depth

Transverse image for width


for nodules > 1.0 cm and any other suspicious nodules

Measure three dimensions (sagital  and transverse images)

Assess colour flow and record image

Primary features of malignancy for nodules



Solid Nodule

Image to assess cystic areas and mural nodules

Colour flow central

Greater than surrounding thyroid

Features suggestive of benignancy

Cystic nodules

Peripheral (eggshell) calcification

Soft findings

Peripheral calcification – benign

Taller than wide – malignant

Profoundly hypoechoic < muscle – malignant

Which nodules to image

All nodules > 1 cm except for multinodular gland with diffuse similar nodules

Any smaller nodules noted to be highly suspicious for malignancy

Solid, microcalcifications, internal colour flow

When to recommend FNA


If > 1.0 cm or smaller nodules if also solid and/or internal colour flow

Mainly solid or macrocalcification

If > 1.5 cm

Not purely cystic (no mural nodule)

 If > 2.0 cm

Substantial interval growth

When to recommend follow up

None of the above

Multinodular gland with diffuse bilateral similar nodules (little visible normal thyroid tissue)

Multiple nodules

Biopsy the largest or most suspicious 2 or 3 nodules > 1.0 cm

Timing of follow up

follow up at 6 months then 12, 24 and 36 months.


Frates Mary C Benson C.B et al Management of Thyroid Nodules Detected at US: Society of Radiologists in Ultrasound Consensus Conference Statement

Radiology, 237, 794-800. December 2005

Norman J MD endocrineweb Fine Needle Biopsy of Thyroid Nodules

Robert T. Pu M.D., Ph.D.,  Jack Yang M.D., Patricia G. Wasserman M.D., Tawfiqul Bhuiya M.D., Kent A. Griffith M.P.H., M.S., Claire W. Michael M.D. Does Hurthle cell lesion/neoplasm predict malignancy more than follicular lesion/neoplasm on thyroid fine-needle aspiration? Diagnostic Cytopathology  Vol 34 Issue 5 pages 330-4 May 2006

Consensus Panel 2004

Welker M.D Mary Jo., Orlov, Diane M.S., C.N.P. Thyroid Nodules  American Family Physician Feb 2003