PAPILLON COURSE on THYROID ULTRASOUND

Section 2 The nodular goiter

Part 6 The shape of the nodule

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This topic is far more simply to digest than the former ones. Nonparallel orientation (NPO) is universally regarded as a suspicious ultrasound characteristic. This has the highest specificity but the lowest sensitivity in detection of papillary cancer. Similarly to other suspicious features, NPO has relevance in the diagnosis of papillary cancer. The diagnostic value of NPO is lower and is lacking, medullary and follicular cancers, respectively.

This is an easy-to-judge parameter, all guidelines agree that a visual inspection is enough to determine the presence or lack of NPO. We must be aware of the weakness of this approach, a 'yes' or 'no' answer makes the judgement easy, however, in the real-world the ratio of nodule' depth to nodule' width is continuous. An experienced investigator takes into account not only those cases when this ratio is larger than 1 but also those cases which are close to but lower than 1.

This course is composed of several parts. It is advised follow the order of the parts.

  1. Introductory course briefly describes the definition of NPO, discusses its role in differential diagnostics and in various forms of thyroid cancers.

  2. Manual on nonparallel orientation serves as a guidance for the reader. The manual can be downloaded in pdf format.

  3. Lectures present the different presentations of NPO and presents the deceptive patterns.

  4. Case studies involve around 20 cases which present beside 5 to 15 ultrasound images, ultrasound videos, as well.

  5. Videolibrary serves the goal of testing the skills by analyzing videos.

 

 

Case study of the topic

For the first time since childhood, a 41-year-old man, a mathematician, underwent a medical examination during a complex screening organized at his workplace. The only abnormality was a thyroid nodule described as a TIRADS 5 category due to a nonparallel orientation. The patient looked closely in the medical literature, where he found that the ATA guideline gives a 70-90% and the ETA system a 26-87% cancer probability for TIRADS category 5 nodules. He said he came to the order only to have another doctor confirm that the nodule was indeed TIRADS 5 category.
Although the lesion did indeed prove to be TIRADS 5, there was minimal if any risk of malignancy based on the ultrasound pattern. The patient said that considering what he was reading, he would only be reassured if the nodule was removed. I failed to convince him that a cytological examination would most likely give a reassuring result. He also withdrew from cytology.

I mention two important conclusions about the case. One is that the risks specified in the procedures are influenced by a great many things. In Hungary, for example, the risk of cancer is significantly lower, probably partly due to iodine deficiency, which increases the proportion of benign nodules. The other one we don't usually consider. People's decisions are not solely driven by rational considerations. Procedures can only be interpreted by a physician experienced in the field. He or she is expected to evaluate a problem in a complex way. We forget that the layman has the same access to what we read, but obviously is not able to make a complex assessment, he often snatches out a piece of data. It would be worthwhile to take the above into account when publishing the guidelines, and to note, for example, that the evaluation of the data requires special expertise.

 

 

 

 

 

 

 

 

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