Determining when to operate on patients with Hashimoto's thyroiditis with nodular lesions: the role of ultrasound-guided fine needle aspiration cytology

Clinical and pathologic features for predicting malignancy in thyroid follicular neoplasms

Background

The cytologic findings of follicular neoplasm do not distinguish between benign follicular adenoma and follicular thyroid carcinoma (FTC). The objective of this retrospective study was to identify clinical and cytologic/pathologic features to predict malignancy in patients preoperatively diagnosed with follicular neoplasms.

Methods

In total, 416 patients with follicular neoplasms who underwent thyroidectomy were reviewed at Seoul St. Mary's Hospital (Seoul, Korea) from January 2010 to June 2018. Clinicopathological features were analyzed retrospectively by complete medical chart review and pathologic slide review.

Results

Thyroid malignancy/noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was diagnosed in 209 patients (50.2%). In total, 59 patients (14.2%) were diagnosed with FTC, 55 patients (13.3%) were diagnosed with follicular variant papillary thyroid carcinoma (fvPTC). The number of patients with PTC-related nuclear changes was higher in the malignancy/NIFTP group than in the benign group (16.3% vs. 1.9%, P<0.001). Multivariate analysis indicated that the significant risk factors for the diagnosis of malignancy/NIFTP include cytologic or pathologic diagnosis with PTC-related nuclear changes, NRAS mutation, and male sex.

Conclusions

The prevalence of malignancy in patients with a preoperative diagnosis of follicular neoplasm was much higher in our study than in previous reports. Cytologic or pathologic PTC-related nuclear changes is a useful predictor of the presence of malignancy. Further studies must be conducted to support our results.

Thyroid Fine-Needle Aspiration in Taiwan: The History and Current Practice

In Taiwan, thyroid cancer is the most common endocrine gland malignancy and the incidence of thyroid cancer has increased four-fold in the past two decades. Fine-needle aspiration is an accurate and cost-effective method of evaluating thyroid nodules and has been the gold-standard diagnostic tool for thyroid tumors in Taiwan since the 1980s. This article reviews the history, current practice, reporting systems, training, and quality assurance for thyroid fine-needle aspiration cytology in Taiwan.

Papillary Thyroid Cancer and Hashimoto's Thyroiditis: An Association Less Understood

Hashimoto's thyroiditis (HT), part of the spectrum of autoimmune thyroid diseases is a major cause of thyroid hypofunction worldwide. Papillary thyroid carcinoma (PTC), the most prevalent of all thyroid carcinomas has been associated with HT. Literature on this association are based on preoperative FNA or post thyroidectomy histopathology reports, which are subject to potential biases. Molecular, hormonal and histopathalogical basis of this association has been hypothesized, however a definite causal association has not been proved till date. This review aims to study the basis of this association and clinical features and management of HT concurrent with PTC. There are no distinctive clinical or radiological features that categorically differentiates HT concurrent with PTC from PTC or which can pick up a nodule harboring PTC in setting of HT. Smaller nodule size and radiological features like hypoechogenecity; hyper vascularity and calcification in a clinical setting of hypothyroidism have a higher odds ratio for malignancy and merit further investigations. PTC associated with HT has been seen to be less aggressive with earlier presentation with lesser chances of extra thyroidal extension and lymph nodal metastasis. The management and follow up of PTC in HT is no different from that of PTC alone. The prognosis of PTC concurrent with HT is better compared to age and stage matched PTC in terms of lower recurrence and disease free and overall survival.

Neck lymph nodes in chronic autoimmune thyroiditis: the sonographic pattern

BACKGROUND

Neck lymph nodes may be involved in the pathogenesis of chronic autoimmune thyroiditis (CAT). This study was undertaken to identify which of the sonographic features of cervical lymph nodes are readily applicable to patients affected by CAT compared to healthy control subjects.

METHODS

We recruited 106 patients (92 females and 14 males) with CAT and 70 control subjects (53 females and 17 males) without clinical, biochemical, and ultrasonographic evidence of thyroid and neck diseases. We performed laboratory tests (thyrotropin, antithyroperoxidase antibodies, antithyroglobulin antibodies, and ultrasonography) to evaluate in each group: (i) thyroid function, autoimmunity, and morphology; (ii) number, topographic distribution (levels I-VI), and morphology of neck nodes (long-axis diameter; short-axis diameter; short-axis/long-axis ratio; absence or presence of hilus).

RESULTS

Total number of neck nodes with long-axis diameter >10 mm was significantly higher in the CAT group than in the control group (mean±standard deviation [SD]: 3.7±2.4 vs. 0.8±1.3; p<0.001) with significantly increased differences in levels II (1.4±0.8 vs. 0.3±0.5; p<0.001), III (2±1.2 vs. 0.3±0.7; p<0.001), and IV (0.7±0.7 vs. 0.07±0.2; p<0.001). More nodes with a hilus were found in the CAT group than in the control group (mean number of nodes±SD: 2.8±1.9 vs. 0.7±1.1; p<0.001). Short-axis diameter of level III (4.4±1 vs. 3.7±1.2 mm; p=0.002) and level IV nodes (3.9±1 vs. 3.1±0.5 mm p=0.030) was increased in CAT patients when compared with healthy controls.

CONCLUSIONS

The present study is the first one aiming at a systematic description of the sonographic pattern of cervical lymph nodes in CAT. An increased number of benign hyperplastic neck nodes, especially in levels II-IV, appears to be a characteristic sonographic finding associated with CAT.

Coexistence of papillary thyroid cancer with Hashimoto thyroiditis

Aims

Conflicting data have been reported with regard to Hashimoto thyroiditis (HT) and risk of malignancy. The aim of this study was to evaluate coexistence of papillary thyroid cancer (PTC) with HT.

Patients and methods

This is a retrospective cohort study in which HT was diagnosed in 452 (F/M ratio = 405:47, median age 53.5 ± 12.1 years) of 7,545 patients qualified for thyroidectomy throughout the years 2002 to 2010. Pathological reports were reviewed to identify prevalence of PTC in HT vs. non-HT patients.

Results

PTC was diagnosed in 106 of 452 (23.5 %) HT patients vs. 530 of 7,093 (7.5 %) non-HT patients (p < 0.001). Metastases to level VI lymph nodes were observed in 81 of 106 (76.4 %) patients with PTC in HT vs. 121 of 530 (22.8 %) patients with PTC in non-HT disease (p < 0.001).

Conclusions

HT was associated with a threefold increase of PTC prevalence as compared to other non-HT thyroid diseases, and the spread of PTC to level VI lymph nodes was four times more frequent in HT than in non-HT patients.

Role of fine needle aspiration cytology in thyroiditis

Fine needle aspiration (FNA) of thyroid is a cost-effective, simple, diagnostic tool in the initial screening of patients with thyroid lesions. Its role in a minimally enlarged thyroid in a symptomatic patient suspected of thyroid dysfunction is now well known. It plays an important role in the medical management of all nonpalpable/minimally enlarged thyroid (goiter) in patients suspect for thyroid pathology and/or in combination with thyroid-stimulating hormone, T3 and T4 levels by diagnosing early cases of thyroiditis. FNA may be of assistance in the early detection of subclinical hypothyroidism, which is of utmost importance in pregnant women, and further makes possible the availability of baseline values for future reference. With the implementation of this protocol of FNA thyroid with/without imaging, we affirm that the practice of cytology has differed in different geographic areas and from country to country, depending on economy and availability of infrastructure.

Thyroid cancer in the thyroid nodules evaluated by ultrasonography and fine-needle aspiration cytology

Thyroid nodule is common disorder in endocrine clinics. In Taiwan, thyroid ultrasonography with fine-needle aspiration cytology (FNAC) is the first-line examination procedure. Data in large series on the incidence of thyroid malignancy presenting with thyroid nodules are lacking in this area. To determine the incidence of malignancy in thyroid nodules and compare the results with other populations, this investigation retrospectively reviewed 21,748 subjects who were examined in one medical center from January 1986 to December 1999. All patients underwent thyroid ultrasonography studies using a real-time ultrasonographic machine and a 10-MHz transducer. Fine-needle aspirations were made in the suspected thyroid nodule and stained using the Romanowsky- based method developed by Liu. By the end of 2002, some 3629 patients (16.7%) had thyroid nodules after surgical treatment. This group comprised 3011 women with a mean age of 41.5 +/- 13.9 years, and 618 men with a mean age of 45.7 +/- 14.9 years. Of patients undergoing surgical treatment, 2761 (76.1%) patients were diagnosed with benign nodules, 858 (23.6%) with malignant nodules, and 10 (0.3%) with atypical adenoma (7 follicular and 3 Hürthle cells). The percentages of thyroid malignancy in each age group revealed two peaks in both genders, namely in patients aged 20 to 29 years and in elderly patients (aged over 65 years). The peak age for thyroid malignancy in both genders was 41 to 60 years (male) and 21 to 40 years (female). The highest ratio of malignancy occurred in the elderly group (37.2%) receiving surgical treatment. In young patients (below 19 years) the percentage of malignancy was no greater than for the whole age group (20.2% versus 25.6%). Anaplastic and metastatic cancers affecting the thyroid were the main subjects in the age group. The present results demonstrated a younger distribution for well-differentiated thyroid cancer, particularly papillary thyroid carcinoma, compared to previous studies. This outcome may have resulted from the routine application of ultrasonography with FNAC in assessing the thyroid nodules, possibly helping to achieve more timely detection. The incidence of thyroid malignancy in young patients was no higher than in adults. Early detection of thyroid malignancy may be the main reason for this phenomenon. Male subjects with thyroid nodules displayed a higher incidence of this malignancy than females. Aging subjects with thyroid nodules suffered a higher rate of malignancy and were poorly differentiated. In conclusion, this retrospective large-series study demonstrated that 3.9% (858/21,748 cases) of patients with thyroid nodules showed histopathologically proven malignancy. Thyroid cancer detected by ultrasonography with FNAC occurred an average of 10 years younger than in prior studies.