Assessment of the Ultrasonological Findings of Goitrogenous Lesions

Abstract

Benign swellings of the thyroid gland are a common occurrence, frequently seen in surgical practice. Regardless of their appearance, however, it is a must to ultrasonologically analyse them in order to confirm their morphology and pick up any warning signs which might point towards a malignant transformation. In this particular study, we analyzed the morphological features (ultrasonological) associated with benign goitrogenous lesions. To analyse specific ultrasonological findings of goitrogenous lesions and assess the frequency of their appearance. Patients meeting the inclusion criteria were included in the study. Detailed history taking and examination was done. Informed and written consent was taken from the patients before participating in the study. Patients suffering from clinically benign goiter underwent ultrasonological analysis of the lesions. The findings were analyzed and the frequency of their appearance were assessed. Significant correlation was found between the TIRADS category of the lesions and the final radiological diagnosis. Most of the lesions were found to be benign ultrasonologically with 4 having features strongly suspicious of malignancy. In our study, lesions diagnosed to be goiters on ultrasonological examination were found to fall in the TIRADS category I-III (benign to mildly suspicious) while lesions with features of thyroiditis fell in TIRADS category I. Glandular echotexture is inhomogeneous in a majority of goitrogenous lesions and the presence of normal thyroid volume does not exclude the presence of goiter.

Introduction

The WHO classifies goiter into three grades: Grade 0 is no palpable swelling, Grade 1 is a mass in the neck which is not visible but is palpable when the neck is in the normal position and Grade 2 is a swelling visible in the normal position which is also palpable clinically and is consistent with an enlarged thyroid gland. It also notes ultrasound to be a safe, feasible investigation when evaluating thyroid nodules, especially when prevalence of visible nodules is small.

This is mostly because clinical palpation of the thyroid gland is noted to be unreliable, especially in Grade 0 and Grade 1 cases, with errors of classification being reported to be as high as 40%. Inter-observer variation is believed to be the reason for the low sensitivity and specificity of clinical palpation [1].

Since most nodules do not produce symptoms that are clinically meaningful, the primary problem in managing them is ruling out malignancy. The pillars of this diagnostic process are ultrasonography (US) and fine-needle aspiration (FNA) biopsies. The following are the main topics covered in the guidelines for managing thyroid nodules: (1) US-guided FNA (henceforth, FNA) indications and risk of malignancy; (2) FNA sample cytologic classification; (3) The application of molecular testing and immunocytochemistry to thyroid FNA; (4) Therapeutic choices; and (5) Follow-up approach. Repeat FNAC (Fine needle aspiration cytology) is recommended in nodules that show a 50% increase in volume [2].

While the increased use of imaging as a diagnostic procedure for thyroid disorders has revealed a high number of incidentalomas and pseudo-diseases, it also helps identify benign thyroid nodules (morphologically) and analyse which ones need cytological analysis and which ones do not [3].

Methodology

Sources of data

Patients suffering from goitrogenous lesions attending the out patient department in hospitals associated with the Bapuji institute.

Sampling procedure

Purposive sampling method.

Study design

Prospective, single centre, cross sectional, descriptive study.

Study duration

12 months.

Sampling criteria

• Inclusion criteria:

  1. Patients between 10 and 70 years of age.
  2. Patients with goitrogenous lesions.
• Exclusion criteria:

  1. Patients suffering from malignancies of the thyroid (proven by FNAC).

Data collection method

Patients meeting the inclusion criteria were included in the study. Detailed history taking and examination were done. Informed and written consent were taken from the patients before participating in the study. Patients suffering from clinical goitrogenous lesions underwent ultrasonological analysis of the lesions. The findings were analyzed regarding appearance of the lesions and were assessed.

Outcome measures

Ultrasound reports of the included patients.

Statistical analysis

Categorical data was represented in the form of frequency and percentage Association between variables was assessed with Chi Square Test and Fisher’s Exact test if the cell values were small.

Quantitative data was represented as Mean & SD (Standard deviation).

Diagnostic accuracy between FNAC & Ultrasound findings was assessed with sensitivity, specificity, PPV (positive predictive value), NPV (negative predictive value).

A p value of < 0.05 was considered statistically significant.

Data was analyzed with IBM SPSS Version 28 for windows.

Results

1. Enlargement of the right lobe was noted in 16 (32%) patients, making it the single most prevalent feature of right lobe involvement by thyroid disease (See Tables 1 and 2).

2. Enlargement of the left lobe was noted in 20 (40%) patients, making it the single most prevalent feature of left lobe involvement by thyroid disease. Enlargement of the left lobe was more prevalent than the right lobe (See Table 1 and 2).

3. In 37 (74%) patients, the isthmus was noted to be normal in thickness (See Table 3).

4. Glandular vascularity was noted to be normal in 34 (68%) patients (See Table 4).

5. Glandular echotexture was noted to be inhomogeneous in 31 (62%) patients (See Table 5).

6. A majority of the lesions fell in the TIRADS category between I and III, ranging from benign to mildly suspicious [6], with a majority of them falling in category I (See Table 6).

7. 23 (46%) of the lesions were diagnosed to be goitre, while 13 (26%) were noted to be thyroiditis, with 6 (12%) cases showing features of both, making goitre and thyroiditis to be the most prevalent diagnoses featuring in our case series (See Table 7).

8. No significant correlation noted between the glandular echotexture and the radiological diagnosis (See Table 8).

9. No significant correlation found between the findings in the right lobe and radiological diagnosis (See Table 9).

10. No significant correlation was found between the findings in the left lobe and the radiological diagnosis (See Table 10).

11. Significant correlations were found between the TIRADS score of the lesions and the final radiological diagnosis. Most of the lesions radiologically diagnosed as goitre and having features of thyroiditis fell in the TIRADS category of I-III. More specifically, the lesions diagnosed as goitre were almost equally likely to fall into category I and III while the lesions having features of thyroiditis were almost exclusively in TIRADS category I, as were the lesions having features of both goitre and thyroiditis. Lesions having strong suspicion of being malignant were put in TIRADS category IV and V. Only 4 lesions out of 50 were noted to have strong suspicion of malignancy (See Table 11).

Table 1.

Ultrasound findings in the right lobe

Right lobe	No of cases	Percent
Enlarged	16	32.0
Hyperechoic lesion	6	12.0
Hypoechoic	5	10.0
Heterogeneous lesion	2	4.0
Anechoic lesion	3	6.0
Isoechoic lesion	3	6.0
Cystic lesion	2	4.0
Normal in size	10	20.0
Well defined lesion	2	4.0
Multiple lesion	1	2.0
Total	50	100.0

Table 2.

Ultrasound findings in the left lobe

Left lobe	No of cases	Percent
Enlarged	20	40.0
Hyperechoic lesion	6	12.0
Hypoechoic	7	14.0
Heterogeneous lesion	1	2.0
Anechoic lesion	3	6.0
Isoechoic lesion	2	4.0
Cystic lesion	1	2.0
Normal in size	8	16.0
Well defined lesion	1	2.0
Multiple lesion	1	2.0
Total	50	100.0

Table 3.

Ultrasonological appearance of the isthmus

Isthmus	No of cases	Percent
Thickened	13	26.0
Normal	37	74.0
Total	50	100.0

Table 4 .

Glandular vascularity

Glandular vascularity	No of cases	Percent
Increased	16	32.0
Normal	34	68.0
Total	50	100.0

Table 5.

Glandular echotexture

Glandular echotexture	No of cases	Percent
Homogeneous	16	32.0
Inhomogeneous	31	62.0
Homogeneous & Inhomogeneous	1	2.0
Normal	2	4.0
Total	50	100.0

Table 6.

TIRADS grading of the final diagnosis

TIRADS	No of cases	Percent
I	28	56.0
II	3	6.0
III	13	26.0
IV	5	10.0
V	1	2.0
Total	50	100.0

Table 7.

Final radiological diagnosis

Diagnosis	No of cases	Percent
Goiter	23	46.0
Thyroiditis	13	26.0
Goitre/thyroiditis	6	12.0
Glandular hypertrophy	1	2.0
Cystic lesion	3	6.0
TIRADS IV, V (likely malignant)	4	8.0
Total	50	100.0

Table 8.

Correlation between glandular echotexture and radiological diagnosis

Diagnosis	Glandular echotexture			Total	p value
	Homogeneous	Inhomogeneous	Homogeneous & inhomogeneous
Goitre	8	14	1	23	0.104
Thyroiditis	2	11	0	13
Goitre/thyroiditis	5	1	0	6
Glandular hypertrophy	1	0	0	1
Cystic lesion	0	3	0	3
TIRADS IV, V (likely malignant)	0	4	0	4
Total	16	33	1	50

Table 9.

Correlation between right lobe findings and radiological diagnosis

Right lobe	Diagnosis						Total
	Goitre	Thyroiditis	Goitre/thyroiditis	Glandular hypertrophy	Cystic lesion	TIRADS IV, V
Enlarged	5	7	3	1	0	0	16
Hyperechoic lesion	4	1	0	0	0	1	6
Hypoechoic	1	1	1	0	1	1	5
Heterogeneous lesion	2	0	0	0	0	0	2
Anechoic lesion	1	2	0	0	0	0	3
Isoechoic lesion	3	0	0	0	0	0	3
Cystic lesion	2	0	0	0	0	0	2
Normal in size	4	1	2	0	2	1	10
Well defined lesion	1	1	0	0	0	0	2
Multiple lesion	0	0	0	0	0	1	1
Total	23	13	6	1	3	4	50
p Value 0.604

Table 10.

Correlation between left lobe findings and radiological diagnosis

Left lobe	Diagnoses						Total
	Goitre	Thyroiditis	Goitre / thyroiditis	Glandular hypertrophy	Cystic lesion	TIRADS IV, V
Enlarged	5	8	3	1	1	2	20
Hyperechoic lesion	2	3	0	0	1	0	6
Hypoechoic	5	1	1	0	0	0	7
Heterogeneous lesion	1	0	0	0	0	0	1
Anechoic lesion	1	0	0	0	1	1	3
Isoechoic lesion	2	0	0	0	0	0	2
Cystic lesion	1	0	0	0	0	0	1
Normal in size	6	0	2	0	0	0	8
Well defined lesion	0	1	0	0	0	0	1
Multiple lesion	0	0	0	0	0	1	1
Total	23	13	6	1	3	4	50
p Value 0.534

Table 11.

Correlation between final diagnosis and TIRADS scores

Diagnosis	TIRADS					Total	p value
	I	II	III	IV	V
Goitre	9	2	11	1	0	23	P < 0.001
Thyroiditis	10	1	2	0	0	13
Goitre/thyroiditis	6	0	0	0	0	6
Glandular hypertrophy	1	0	0	0	0	1
Cystic lesion	2	0	0	1	0	3
TIRADS IV, V (likely malignant)	0	0	0	3	1	4
Total	28	3	13	5	1	50

Discussion

Research backs up the idea that the best method for evaluating the size and morphology of the thyroid is often high-resolution ultrasound sonography. Ultrasonography, which was first employed by a small group of enthusiasts from several medical specialties, is now widely used in clinical thyroidology. Thyroid ultrasonography has historically been carried out by clinical physiologists and diagnostic radiologists, however thyroidologists have been urged to become proficient in this technology due to the trend of using as few physicians as possible in patient care [5]. Although ultrasonography is useful in the diagnosis of nodular goitre and chronic thyroiditis (CT), it is frequently reserved for patients with hypothyroidism if a thyroid mass or palpable goitre is found [6].

It has been noted that classifying lesions based purely on their morphological patterns rather than individual sonological features was highly accurate in diagnosing benign lesions [3]. Additionally, we found 31(62%) of the lesions to have inhomogeneous echotexture and 46 (92%) of the lesions to be benign, suggesting a close correlation between the two.

Shape, margin, echogenicity and the presence of calcifications have been noted to be useful in telling benign lesions from malignant ones [7]. In our study, hyperechogenicity and isoechogenicity were more closely associated with the diagnosis of goitre, particularly in right lobe lesions.

We also found that a normal size/volume of the gland is not an accurate predictor if normalcy and normal glandular size does not exclude the existence of goitre. Similar conclusions were reached by Berghout et al. in 1987 [8].

The most significant finding in our study was the correlation between the TIRADS category of the lesion and the final radiological diagnosis. This indicated where the lesions lay on the benign-to-malignant spectrum as noted by goitres equally likely to be in TIRADS category I and III while lesions having features of thyroiditis were almost exclusively in category I. In another study, multinodular goitres were most likely to lie in the TIRADS II category [9].

We have found that there has been some overlap between the types of lesions reported, since according to the sonologist’s reports, some patients had lesions with varying consistencies and echogenicity in the same as well as contralateral lobe. Wordings used by the sonologists may not be consistent in all cases regarding the type of lesions, hence leading to the discrepancy.

For a majority of the lesions reported in the ultrasonography reports, the TIRADS category was given by the sonologists. Manual calculation of the TIRADS score was done only for lesions for whom the grading was missed.

Conclusions

In our study, lesions diagnosed to be goitres on ultrasonological examination were found to fall in the TIRADS category I-III (benign to mildly suspicious) while lesions with features of thyroiditis fell mostly in TIRADS category I. Glandular echotexture is inhomogeneous in a majority of goitrogenous lesions and the presence of normal thyroid volume does not exclude the presence of goitre.

Authors’ contribution

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Dr. Akshay Krishnamurthy, Dr. Santosh U.P., Dr Arfan Nasser and Dr Shubhi Saumya. The first draft of the manuscript was written by Dr. Akshay Krishnamurthy and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Funding

The authors have no relevant financial or non financial interest to disclose.

Data Availability

The data used in this study was not used/published in any other publication.

Code Availability

The data was compiled and analysed using IBM SPSS STATISTICS version 28.0.

Declarations

Ethics Approval

The study was done after approval of the Institutional Ethics committee from JJM Medical College, Davangere, Karnataka, India in accordance with ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Consent to Participate

Written informed consent was taken from all the patients.

Consent for Publication

All authors have reviewed the manuscript and approved the version to be published.

Conflict of Interest

The Authors declare that there is no conflict of interest.