Ultrasonographic Characteristics of Thyroid Nodules with Nondiagnostic and Atypia of Undetermined Significance in Fine-Needle Aspiration Cytology

Objectives

This study aimed to investigate ultrasound (US) features of thyroid nodules categorized as nondiagnostic (ND) and atypia of undetermined significance (AUS) according to the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) and their potential implications for clinical management.

Materials and Methods

A retrospective study was conducted on patients who underwent thyroid nodules FNAC between 2019 and 2023. Nodules falling into the ND and AUS categories were analyzed for US features, nodule size, composition, echogenicity, shape, margin, echogenic foci, the distribution of the American College of Radiology's Thyroid Imaging Reporting and Data System (ACR TI-RADS) categories, and other parameters. The study included a total of 1,199 patients and 1,252 nodules (ND: 1110; AUS: 142).

Results

No significant differences in age, gender, nodule features, echogenicity, shape, margin, echogenic foci, TI-RADS scores, localization, number of nodules, or thyroid parenchymal disease presence were found between the ND and AUS categories (p > 0.05). Also, no statistically significant difference in nodule size (<10 mm vs. ≥10 mm) existed between the ND and AUS categories (p = 0.475). Both showed predominantly solid composition and hyperechoic/isoechoic echogenicity. High proportions of TI-RADS 4 nodules were observed in both groups, with 727 (65.5%) in ND and 95 (66.9%) in AUS.

Conclusion

This study found no statistically significant differences in US characteristics between the ND and AUS categories, indicating potential similarities in their radiological appearances. Also, no significant difference in nodule size (<10 mm and ≥10 mm) was observed between these categories. Clinical management should consider further investigations, including repeat FNAC, due to the diagnostic challenges and malignancy risk in both categories.

Clinical Utility of Fine Needle Aspiration Cytology for Adenoid Cystic Carcinoma of the Trachea with Thyroid Invasion: A Case Report

BACKGROUND

Adenoid cystic carcinoma of the trachea (ACCT) is a rare cancer; ACCT with thyroid invasion is particularly rare. We first suspected anaplastic thyroid carcinoma (ATC) but diagnosed ACC after performing fine needle aspiration cytology (FNAC). A tracheal origin was confirmed after operation.

CASE DESCRIPTION

We report the case of a 77-year-old female presenting to our hospital with acute inspiratory dyspnea requiring emergency tracheotomy. Physical examination revealed a right anterior neck swelling with a hard and unmovable mass. Computed tomography (CT) and ultrasonography (US) showed tumor extension to the right thyroid lobe, and between the first and third tracheal rings, which caused severe stenosis of the lumen. Next, we performed FNAC. Clinical findings were highly suspicious for ACCT with thyroid invasion. Thirty-five days after the first visit to our department, the patient underwent total laryngectomy, cervical esophagectomy, and thyroidectomy with bilateral selective neck dissections at another hospital. The tumor was located in the right posterior wall of the trachea, with extension into the right thyroid gland. Pathological examination showed an infiltrative carcinomatous proliferation with tubular and cribriform patterns. The tumor was classified as pT4N1. A definite diagnosis was made after histopathological analyis of the surgical specimen confirmed ACCT. The tumor was found to be positive for FABP7, a putative prognostic marker of ACC, and metastasized to the lungs 3 years after the surgery.

CONCLUSIONS

ACCT with thyroid invasion is an extremely rare malignant neoplasm. FNAC was useful for differentiating ACCT from other diagnoses and enabled appropriate surgical treatment.

Malignancy rates in thyroid nodules classified as Bethesda categories III and IV; a subcontinent perspective

BACKGROUND

Bethesda category III and IV thyroid nodules fall in the indeterminate risk of malignancy category. These nodules have been a relatively elusive entity to manage as previous studies have shown a wide variation in malignancy rates in different regions and institutions across the world. However, data from the subcontinent with regards to this is scarce.

AIM AND OBJECTIVE

This study aimed to determine the characteristics and malignancy rates of cytology proven Bethesda Category III and IV thyroid nodules and its association with clinical, histopathological and laboratory variables, in the regional population.

METHOD

A retrospective search was performed on all patients with thyroid nodules who presented to this hospital, from January 2011 to September 2018. Patients who had cytology proven Bethesda category III and IV thyroid nodules that underwent surgery were included in the study.

RESULTS

Malignancy in Bethesda Category III and Bethesda Category IV thyroid nodules was 29.6% and 47.1%, respectively. There was no significant association determined between malignancy rate and various clinical, histopathological, and radiological characteristics.

CONCLUSION

The malignancy rates in Bethesda category III and IV thyroid nodules in this study are significantly higher than that initially suggested by the Bethesda consensus publication but is comparable to international data present.

Intra-muscular Nodular Fasciitis Presenting as Swelling in Neck: Challenging Entity for Diagnosis

The diagnosis of Nodular Fasciitis is a very challenging on cytological aspirations. Even in histopathological sections, it can be sometimes be mistaken for soft tissue sarcomas due to its high cellularity, presence of mitotic figures, poor circumscription and degenerative myxoid areas. Most commonly, nodular fasciitis is seen on extremities; and sub-cutaneous form is most common. We are hereby reporting a case of nodular fasciitis at a rare site (head and neck area) in its rare form (intra-muscular type: originating within sternocleidomastoid muscle), which was clinically suspected as a malignancy arising from solitary thyroid nodule. Cytological diagnosis was issued as benign spindle cell lesion (where chances of a misdiagnosis as malignant are very high), thereby preventing radical surgery. It was subsequently confirmed as intra-muscular nodular fasciitis after histopathological examination.

A comparative study of fine needle aspiration cytology, ultrasonography and radionuclide scan in the management of solitary thyroid nodule : A prospective analysis of fifty cases

Solitary thyroid nodule is a common clinical entity encountered by the otorhinolaryngologist and physcians. The optimum diagnostic strategy for the euthyroid patient with a soilitary thyroid nodule is still a matter of debate. The goal of diagnostic workup now is to select those patients for surgery who have a high likelihood of harbouring malignancy in the solitary thyroid nodule. The present study was undertaken to evaluate the utility of FANC in the preoperative diagnosis of solitary thyroid nodule and to evaluate the efficacy of FNAC, VSG and RNS in differentiating between benign and malignant nodules. It was found that FNAC is a safe, reliable and cost effective diagnostic modality with a high sensitivity of 83.3% and specificity of 100% and is the single best investigation for preoperative evaluation of solitary thyroid nodules to differentiate between benign and malignant nodules.