PAPILLON COURSE on THYROID ULTRASOUND

Case of the Month

October 2021 - case 3

Summary and comments

49 participants have answered the questions.

For watching the full case study, click here.

1. How to judge the right lobe regarding the presence of pathological nodule?

Distribution of answers

There is no pathological nodule 21

The presence of nodules is doubtful 11

The lobe has pathological nodule 17

No 41

Expert comment

It is not obvious whether the right lobe has a nodule or has not. In my opinion, the larger and most bright area in the lower pole of the lobe corresponds to the largest part of the lobe which is not or less influenced by the underlying thyroiditis (between 0:08 and 0:15 seconds in the video). Note the irregular contours of this mass. It is also worth comparing this lesion with the largest echonormal one in the left lobe. The latter is more probably a true nodule.
Also considering the uncertainties of the judgment, I suggest that in the case of the lesion in question in the right lobe, we should not use the unambiguous 'nodule' term in the report. Instead, we can write a 'discrete lesion' or a 'nodule-like lesion', for example.

2. How to describe the echogenicity of the thyroid?

Distribution of answers

The thyroid is composed of minimally/moderately and deeply hypoechoic areas. 40

The thyroid is deeply hypoechoic. 7

The thyroid is echonormal and has hypoechoic areas. The echogenicity index is around 50%. 1

The thyroid is iso/hyperechoic. 1

Expert comment

I think that the correct answer is the first one. Even the less hypoechoic areas are darker than a healthy thyroid. The minimally/moderately hypoechoic areas prevail over deeply hypoechoic fields, therefore, if we want to put it more simply, it seems more correct to write that the thyroid is minimally/moderately and not deeply hypooechogenic.

3. How to classify the echogenic lines and granules in the thyroid?

Distribution of answers

These are presentations of connective tissue. 40

These are back wall figures caused by posterior enhancement. 6

Some of them are microcalcifications. 3

Expert comment

The simultaneous presence of bright echogenic lines and granules can mean two conditions, connective tissue and if they are found dorsal to cystic areas, then back wall figures. In great proportion of Hashimoto' s thyroiditis, it is difficult to discriminate between anechoic (cystic) and deeply hypoechoic fields. Nevertheless, we know that deeply hypoechoic areas are essential components of thyroiditis while diffusely occurring cystic parts are not. Moreover, even small cystic areas have regular round or oval shapes. And already in this thyroid, a significant portion of the very hypoechoic areas in question are typically irregular in shape which is characteristic of thyroiditis.
Microcalcifications can be interpreted only within a nodule or in the very close areas outside the nodule. In this patient, the hyperechoic granules were found everywhere in the thyroid and are presentations of connective tissue.
To summarize, I agree with the majority, the echogenic figures are presentations of connective tissue.

4. How to describe the largest lesion in the lower pole of the left lobe?

Distribution of answers

Compared to the extralesional tissue, the nodule is iso/hyperechoic while compared to a healthy thyroid, the lesion should be regarded as minimally/moderately hypoechoic. 28

This is an iso/hyperechoic nodule. 11

Irrespectively of the reference tissue, this is a dominantly iso/hyperechoic, heterogeneous nodule. 8

This is a minimally/moderately hypoechoic nodule. 2

Expert comment

If we compared the nodule' echogenicity to that of the extranodular tissue (or as the EU-TIRADS suggest in hypoechoic thyroids, to the salivary gland), then the lesion should be classified as iso/hyperechoic. However, if the reference tissue would be a normal healthy thyroid than the nodule should be regarded as minimally/moderately hypoechoic.
It means, that the first or second responses are acceptable. The first one is the more accurate.

5. Is FNA indicated based on EU-TIRADS??

Distribution of answers

Yes 40

No 8

Uncertain 1

Expert comment

The answer depends on the judgement of nodule' echogenicity. If this is considered as iso/hyperechoic than EU-TIRADS does not suggest cytology because in this case the nodule would be an EU-TIRADS 3 lesion. If we consider the nodule as minimally/moderately hypoechoic than FNA would be indicated according to the EU-TIRADS.

6. Did you personally indicate FNA in this lesion?

Distribution of answers

Yes 40

No 9

Expert comment

This is not an obvious situation and naturally, both answers must be accepted. I personally would perform FNA. Although the risk of cancer is very low in this nodule, but a follicular tumor should be considered in a solitary lesion presenting halo. There is no other chance of recognizing follicular cancers at the stage when they do not yet have a distant metastasis than to perform a cytological examination in echonormal nodules smaller than 2 cm that show halo and/or perinodular blood flow. The approach of TIRADS is the opposite. (A detailed explanation of the problem can be found in the TIRADS chapter.)