|Year : 2019 | Volume
| Issue : 3 | Page : 411-417
Prospective study evaluating malignancy in solitary thyroid nodule
Mohamed M El Sayed Ibrahim1, Wael Omar2, Ahmed Elhofy1
1 Department of Surgery, Ain Shams University, Cairo, Egypt
2 Department of Surgery, Helwan University, Helwan, Egypt
|Date of Submission||27-Jan-2019|
|Date of Acceptance||05-Mar-2019|
|Date of Web Publication||14-Aug-2019|
Department of Surgery, Helwan University, Helwan
Source of Support: None, Conflict of Interest: None
Objective The aim of this study was the preoperative evaluation of patients with solitary thyroid nodules (STNs) for the presence of malignancy to avoid unnecessary total thyroidectomy.
Patients and methods A total of 83 patients with STNs who underwent hemithyroidectomy, total thyroidectomy, and total thyroidectomy with modified neck dissection in Ain Shams University Hospitals and Helwan University Hospital between September 2016 and December 2017 were evaluated. Parameters including demographics, ultrasonographic, and pathological data were analyzed.
Results After evaluation of the final pathology, results showed that malignancy was found in 33/83 (39.8%) patients. A total of 24 (72.7%) of these lesions were papillary carcinoma. Multinodular goiter accounted for 90% of all benign cases. Of 19 malignant cases, 14 (73.7%) were males, whereas of 64 benign cases, 45 (70.3%) were female patients. Nodule echogenicity, nodule calcification, nodule vascularity, nodule shape, and nodule margins were found to have significant prediction for malignancy. Among these factors, increased vascularity and irregular nodule margins were the most important factors. Nodule size did not affect the risk of malignancy. Moreover, lymph node characteristics were found to have significant prediction for malignancy. The FNA results of BII-V reports showed that 17.2% of patients with STN nodule had false negative results.
Conclusion Multivariate analysis revealed that in STN, the highest malignancy predictor was the ‘No halo and irregular Margin’ in ultrasound, and that microcalcifications, hypoechoic, and taller nodules were highly suspicious factors for malignancy.
Keywords: hemithyroidectomy, solitary thyroid nodule, total thyroidectomy
|How to cite this article:|
El Sayed Ibrahim MM, Omar W, Elhofy A. Prospective study evaluating malignancy in solitary thyroid nodule. Egypt J Surg 2019;38:411-7
|How to cite this URL:|
El Sayed Ibrahim MM, Omar W, Elhofy A. Prospective study evaluating malignancy in solitary thyroid nodule. Egypt J Surg [serial online] 2019 [cited 2019 Nov 20];38:411-7. Available from: http://www.ejs.eg.net/text.asp?2019/38/3/411/264351
| Introduction|| |
Solitary thyroid nodule (STN) is one of the common thyroid presentation, and approximately 8% of the adult population presents with clinically palpable thyroid nodules . Use of imaging techniques, particularly ultrasound, has increased the chance of detection of the thyroid nodules greatly . Patients with STN must be further evaluated for other nodules 
The reported incidence of thyroid cancer in general population is low, being approximately 1%. Thyroid cancers occur in ∼5% of all thyroid nodules independent of their size . The occurrence of malignancy is more in STNs compared with multinodular goiter .
The preoperative evaluation of thyroid nodules to distinguish between benign and malignant nodules is very important. It helps to avoid unnecessary extensive surgery and potential surgery-related adverse effects, such as hypothyroidism, hypocalcemia, and recurrent laryngeal nerve injury .
The aim of this study was to evaluate patients with STN for the presence of malignancy, in relation to various factors like age, sex, and ultrasonography findings like size of the nodule, echogenicity, microcalcification, and presence of lymphadenopathy to detect various malignancy predictors to avoid unnecessary extensive surgery and its complications.
| Patients and methods|| |
This study was conducted in Endocrine-Surgery Unit of Ain-Shams University Hospital and Helwan University Hospital on 83 patients who underwent surgery for STN between September 2016 and December 2017.
The study group consisted of 83 patients who presented with clinically palpable STN and confirmed radiologically by ultrasound.
Written informed consent was obtained from all patients before being assigned to surgery.
The surgical details and complications of different procedures including hemithyroidectomy, total thyroidectomy, and total thyroidectomy with modified neck dissection were discussed in detail with the patients.
The following data were recorded from all patients: age, sex, family history of thyroid cancer, and previous history of irradiation.
The preoperative laboratory tests included thyroid function test (free T3, free T4, and thyroid-stimulating hormone) and serum calcium. Preoperative workup included neck ultrasound with analysis of the following data: nodule size, echogenicity, calcification, vascularity, shape, and margins. It also assessed the presence of cervical lymphadenopathy with analysis of the following data: lymph node size, echogenicity, calcification, color Doppler, and shape.
Fine needle aspiration cytology (FNAC) was done in all patients, and its results were analyzed using the Bethesda system for reporting thyroid cytopathology ([Table 1]). Workup included also chest radiography, ECG, and indirect laryngoscopy.
A total of 83 patients underwent surgery for STN, and type was decided depending on several factors, including patient history, ultrasound finding, presence of suspicious lymph nodes, preoperative FNAC, and patient counseling.
Hemithyroidectomy was done in benign nodules as reported by FNAC Bethesda II. A total of 35 patients underwent hemithyroidectomy, and in only one case where postoperative histopathology was reported as malignant in the paraffin section, completion thyroidectomy of the remaining lobe was done. Total thyroidectomy was done in those cases where FNAC was reported as Bethesda III–VI. In total, 40 patients underwent total thyroidectomy. Total thyroidectomy with neck dissection was done in those cases with either palpable lymph nodes in the neck or ultrasonic finding suggestive of lymphadenopathy. Only eight patients underwent total thyroidectomy with neck dissection.
Continuous variables are expressed as mean and SD. Categorical variables are expressed as frequencies and percentages. Student’s t-test was used to assess the statistical significance of the difference between two study group mean. χ2-Test and Fisher’s exact test were used to examine the relationship between categorical variables. A significance level of P less than 0.05 was used in all tests. All statistical procedures were carried out using SPSS version 20 for Windows (SPSS Inc., Chicago, Illinois, USA).
| Results|| |
Results show that most patients presenting with STN were females (n=64, 77.1%). Mean age was 36.96±11.1 years, with a range (minimum–maximum: 19–55 years). Most of the patients (n=78, 94%) were euthyroid, three patients were hyperthyroid, and only two patients were hypothyroid ([Table 2]). The most common presentation of the patients is swelling in the anterior aspect of the neck discovered accidently, and other symptoms included pain, hoarseness, and dysphagia.
The preoperative radiological and pathological assessment findings were presented in [Table 3],[Table 4],[Table 5]. It shows regarding the preoperative ultrasound that the most important factors to be included in the ultrasound are the nodule size, which was divided into three groups less than 2, 2–4, and greater than 4 cm. The echogenicity is divided into solid and cystic, and the solid is furtherly divided into hyperechoic, isoechoic and hypoechoic lesions. Calcification, which is present in less than 50% of cases, included microcalcifications, coarse calcifications, and peripheral rim calcification. Moreover, an important factor is the nodule vascularity. Other factors include nodule shape and margins [Table 3].
Regarding the lymph nodes, the size, echogenicity, calcification, vascularity, and shape were recorded ([Table 4]). Moreover, the results of preoperative FNAC are shown in [Table 5].
| Discussion|| |
STNs are defined clinically as a localized thyroid enlargement with an apparently normal adjacent gland. According to literature, STN has a higher risk of malignancy than multiple nodules . Because of this reason, surgeons tend to treat them with high degree of suspicion and plan treatment in a systematic manner. Clinically, STNs are common, being present in up to 50% of the elderly population. Most STNs are malignant ,,.
In our study, the rate of malignancy was 39.8% (n=33). There was a higher incidence of malignancy in males (n=14/19 male, 73.7%), although most presenting patients were females, the rate of malignancy in females was 29.7% (n=19/64 female). On analyzing the age, there was a significant difference in the mean age between benign (35.02) and malignant (39.91) groups. All malignant patients were euthyroid.
On comparing our results with the literature, we found this high incidence of malignancy reported in our study (39.8%) is mostly similar to that of Tai et al.  and Jena et al.  who reported the rate of malignancy in STNs as 33.6 and 39.7%, respectively. However, several authors reported that the detection of malignancy did not correlate with patients’ sex ,,. Tai et al.  and Jena et al.  reported that the rate of malignancy was higher in males, and not only that, Tai et al.  stated that male sex is an independent predictor of malignancy, which is in accordance with our study and other studies as well ,.
[Table 6] and [Table 7] show the final pathology of the patients, which shows that most of the malignant patients were papillary (n=24, 72.7%) with follicular rate (n=6, 18.18%), and most of the benign patients had nodular goiter (n=45, 90%). These results are in accordance with Jaheen and Sakr , as they reported that the rate of papillary carcinoma in STN is 72.5% and follicular carcinoma rate is 17.2%.The US findings showed that the size of the nodules does not indicate malignancy and one can find benign large STNs. It also shows that the most important US findings include the increased vascularity and the irregular nodule margins, and to a lesser extent the microcalcification, hypoechoic nodule echogenicity, and being taller than wider. Similar results were reported by other studies that investigated the ultrasound findings and the risk of malignancy in STN , ([Table 8]).
|Table 6 Analysis of demographic data and thyroid function between types of pathology groups|
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|Table 8 Analysis of thyroid scan findings between types of pathology groups|
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[Table 9] shows the lymph node characteristics that predict malignancy, as it indicated the suspicious lymph nodes as follows: larger than 8 mm, cystic echogenicity, presences of microcalcification, increased vascularity, and loss of normal fatty hilum.
|Table 9 Analysis of lymph node findings between types of pathology groups|
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[Table 10] shows the operative time of different benign and malignant patients who underwent hemithyroidectomy, total thyroidectomy, and total thyroidectomy with neck dissection. It shows significant increase in the time of operation in total thyroidectomy with neck dissection with mean operative time ∼132 min. By comparing the operative time of total thyroidectomy in being and malignant cases, there was no significant difference.
[Table 11] shows the different age groups of benign and malignant patients who underwent different types of surgeries. We divided the age groups into four groups, which is less than 25 year, 25–35 years, 36–45 years, and greater than 45 years, and the results showed that there is no age group at higher risk than the others, and the difference was not highly significant among age groups, but this needs further investigation and larger number of patients to be accurate.
[Table 12] shows the comparison between the results of preoperative FNAC and the postoperative final pathology, which shows that all results if less than BIV were benign and it did not have any false-positive results, whereas greater than or equal to BIV results were benign as well as malignant cases, and all malignant cases were included in greater than or equal to BIV. Moreover, this means that its sensitivity is 100% (no false negative cases), whereas its specificity is 54% (high false-positive cases).
By studying the age and sex as single predictor factors of malignancy, it was found the that the being a male patient is highly significant single intendent factor (P=0.003), but no significant effect of age was found, as shown in [Table 13] and [Table 14].
Moreover, by using multivariate regression to study independent factors in the thyroid nodule predicting malignancy, it was found that the strongest independent factor in our study was the ‘No halo and irregular Margin’ in U/S, and that microcalcifications, hypoechoic, and taller nodules were highly suspicious factors for malignancy.
| Conclusion|| |
Our study results show high incidence of malignancy within clinically detected STN and the presence of the following factors increases the incidence of malignancy: microcalcification, ultrasonography showing solid echogenicity, and lymphadenopathy detected either clinically or by U/S. Therefore, we highly recommend treating STN with high degree of suspicion, and the patient should undergo further investigations by U/S and FNAC.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12], [Table 13], [Table 14]