Vanishing tumors of thyroid: histological variations after fine needle aspiration

Analysis of vanishing endometrial cancer by pathological types

PURPOSE

We asked why endometrial cancer sometimes vanishes.

METHODS

A total of 454 patients diagnosed with endometrioid-type endometrial cancer (EC) (via endometrial sampling) and treated in our clinic over the past 5 years were enrolled. The patients were divided into two groups: vanishing and residual, depending on whether a tumor was detected in the postoperative hysterectomy specimen. Patient age, numbers of pregnancies and deliveries, menopausal status, systemic disease status, hemogram parameters, International Federation of Gynecology and Obstetrics (FIGO) grade, and invasion status (evident on magnetic resonance imaging [MRI]) were compared between the groups.

RESULTS

ECs vanished in 42 (9.25%) patients. The vanishing rates were 19.7% (37/187) in FIGO grade 1 patients, 2.1% (5/238) in grade 2 patients, and 0% (0/29) in grade 3 patients. The average age was lower in the vanishing than the residual group, but the premenopausal status and grade 1 tumor rates were higher (both p < 0.001). An absence of invasion (as revealed by MRI) was more common in the vanishing group (p < 0.001). No recurrence developed in the vanishing group, but recurrences were noted in 3.3% (14/412) of the residual group. There were no significant between-group differences in any of the numbers of pregnancies or births, systemic disease status, or hemogram parameters (all p > 0.05).

CONCLUSION

Vanishing EC is more likely in premenopausal women with endometrioid grade 1 EC (as revealed by endometrial biopsy) who lack myometrial invasion on MRI.

Effect of the size of benign thyroid degenerative nodules on ACR TI-RADS categories

PURPOSE

Our study aimed to identify ultrasound characteristics of benign thyroid degenerative nodules and reveal the correlation between their sizes and 2017 ACR Thyroid Imaging Reporting and Data System (TI-RADS) categories.

METHODS

A total of 174 thyroid degenerative nodules were divided into three groups: 0.5-1 cm group (70 nodules), 1-2 cm group (27 nodules), and > 2 cm group (77 nodules). The ultrasound appearance of each nodule was evaluated, and the ACR TI-RADS scores and levels of the nodules were also calculated and compared among the three groups.

RESULTS

The ultrasound appearance of degenerative nodules of different sizes is diversified, and the 0.5-1 cm group tended to have more malignant features and higher TI-RADS scores and categories. The scatterplot of Spearman correlation showed a significant negative correlation between the nodule sizes and TI-RADS categories.

CONCLUSION

The 2017 ACR TI-RADS, which recommends fine-needle aspiration according to the nodule size and category, is still useful in managing these nodules, and following the clinical recommendations of ACR TI-RADS is necessary.

Overview of the Ultrasound Classification Systems in the Field of Thyroid Cytology

The increasing application of ultrasound (US) in recent years has led to a greater number of thyroid nodule diagnoses. Consequently, the number of fine needle aspirations performed to evaluate these lesions has increased. Although the majority of thyroid nodules are benign, identifying methods to define specific lesions and tailor risk of malignancy has become vital. Some of the tools employed to stratify thyroid nodule risk include clinical factors, thyroid US findings, and reporting systems for thyroid cytopathology. Establishing high concordance between US features and cytologic diagnoses might help reduce healthcare costs by diminishing unnecessary thyroid procedures and treatment. This review aims to review radiology US classification systems that influence the practice of thyroid cytology.

BRAFV600E mutation combined with American College of Radiology thyroid imaging report and data system significantly changes surgical resection rate and risk of malignancy in thyroid cytopathology practice

Background

Ultrasonography patterns and molecular testing may assist in stratifying the malignancy risk of indeterminate cytology diagnosis. The purpose of this study was to assess the value of fine needle aspiration (FNA) cytology in combination with American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) and BRAF^V600E mutation in differentiating high-risk thyroid nodules.

Methods

From February 2010 to February 2014, 2,643 consecutive thyroid nodules from 2,399 patients (688 men and 1,711 women; mean age, 44.3±12.5 years) who underwent preoperative FNA biopsies were enrolled. The Jiangsu Institute of Nuclear Medicine has adopted TI-RADS stratification and BRAF^V600E mutation analysis as a routine procedure to assist in evaluating FNA cytopathology since January 2016. From February 2017 to July 2018, 1,905 thyroid nodules of 1,837 patients (501 men and 1,336 women, 49.5±12.8 years) who underwent preoperative ultrasound-guided FNA biopsies with BRAF^V600E mutation analysis and ACR TI-RADS grading data available were enrolled for comparison in this study.

Results

The cancer risk in nodules with BRAF^V600E mutation was 99.7% (905/908) according to the histological findings. The risk of malignancy (ROM) was found to increase with advancing ACR TI-RADS category. High-risk ultrasound features (TI-RADS 5) did show a good performance in predicting malignancy (98.1%). The combination of TI-RADS 5 and BRAF^V600E mutation reached the best diagnostic efficiency [sensitivity 97.7%, specificity 94.8%, positive predictive value (PPV) 99.6%]. It is apparent that after the implementation of ACR TI-RADS and the BRAF^V600E mutation analysis, the resection rates (RRs) of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) I and III categories showed significant decreases (39.1% vs. 21.6% and 36.1% vs. 16.7%, respectively). In contrast, the risks of malignancy of TBSRTC I and III categories indicated substantial increases (41.5% vs. 80.0% and 34.6% vs. 50.0%, respectively). The ROM of thyroid nodules with nondiagnostic (ND, I) category showed the most significant increase of 41.5% to 80.0%.

Conclusions

ACR TI-RADS, together with BRAF^V600E mutation and cytological diagnoses, can assist in improving the prediction of malignancy of thyroid nodules, especially in the TBSRTC I and III categories.

Degenerating Thyroid Nodules: Ultrasound Diagnosis, Clinical Significance, and Management

Degenerating nodules (DNs), which primarily manifest as benign thyroid nodules, are one of the main causes of discordance in ultrasonography (US) and cytological assessments. Intranodular hemorrhage is one of the mechanisms contributing to discordant nodules, and an impaired blood supply may explain further DN shrinkage and infarction. The surgical specimens can be divided into acute and chronic stages based on the histological changes, which usually mimic the US features of malignant tumors. Serial US follow-up should be recommended instead of other unnecessary procedures. However, repeated fine-needle aspiration, diagnostic surgery, or core-needle biopsy may still be necessary for indeterminable or highly suspicious DNs.

VANISHING PAPILLARY THYROID CARCINOMA: MORPHOLOGICAL CHANGES AFTER FINE-NEEDLE ASPIRATION

Objective

Fine-needle aspiration (FNA) of a thyroid nodule is typically considered a benign procedure. Uncommonly, morphological changes can occur in the nodule or tissue after the procedure. These changes have been noted in tissues like thyroid, breast, lymph node, and prostate. The objective of this case report is to report the rare occurrence of thyroid cancer diagnosed on FNA, appearing as a necrotic mass after near total thyroidectomy and to emphasize the need for confirmation of diagnosis with histopathology.

Methods

A 69-year-old man was seen for a self-discovered neck mass. Thyroid ultrasound demonstrated a thyroid nodule with suspicious features. Ultrasound-guided FNA of the nodule was performed with a 22-gauge needle without immediate complications.

Results

The cytology was read as consistent with papillary thyroid cancer with a preoperative thyroglobulin level of 15,288 ng/mL (normal range is 1.6-55 ng/mL). After a near total thyroidectomy, histopathology revealed complete infarction of the tumor with no evidence of cancerous tissue remaining. Based on the pathology report, he was considered cured of the cancer and did not receive radioactive iodine therapy.

Conclusion

The occurrence of tissue infarction following FNA of a thyroid nodule is rare, reportedly <2%. We conclude a review of the original cytology material and a thorough examination of remaining viable tissue be made. Complete evaluation for invasion of the capsule or surrounding tissue must be ascertained to decrease diagnostic errors.

Detection of BRAF V600E Mutations With Next-Generation Sequencing in Infarcted Thyroid Carcinomas After Fine-Needle Aspiration

OBJECTIVES

Fine-needle aspiration (FNA) of thyroid lesions may result in infarction and diagnostic difficulties on subsequent thyroidectomy specimens. Next-generation sequencing (NGS) methods for detection of hallmark driver BRAF V600E mutations may help characterize such tumors in which histologic alterations preclude definitive tissue diagnosis.

METHODS

Thyroidectomy specimens with both malignant FNA diagnoses and resultant infarction were identified from our institutional database. NGS methods were used to detect BRAF V600E mutations in the infarcted thyroid carcinomas.

RESULTS

Nine thyroid carcinomas with infarction were characterized as BRAF-like papillary thyroid carcinoma based on molecular driver categorization and histologic diagnosis. BRAF V600E mutations were detected in the infarcted tissue in four (67%) of six lesions.

CONCLUSIONS

We demonstrate detection of hallmark BRAF V600E mutations by NGS within infarcted tissue of thyroid carcinomas after FNA. This suggests a potential ancillary method of characterizing infarcted thyroid carcinomas whose altered histology may be nondiagnostic.

Active Surveillance for Patients With Papillary Thyroid Microcarcinoma: A Single Center's Experience in Korea

CONTEXT

Papillary thyroid microcarcinoma (PTMC) usually has an excellent prognosis.

OBJECTIVE

To evaluate the three-dimensional structures of PTMCs, using serial neck ultrasonography (US) in patients under active surveillance.

DESIGN AND SETTING

A retrospective cohort study.

PARTICIPANTS

In total, 192 patients diagnosed with PTMC under active surveillance for >1 year were included in a median 30-month follow-up. Changes in tumor size were evaluated not only using the maximal tumor diameter but also the tumor volume.

RESULTS

The median age of patients was 51.3 years and 145 patients (76%) were female. The median initial maximal tumor diameter and tumor volume were 5.5 mm and 48.8 mm3, respectively. The tumor size increased in 27 patients (14%); 23 patients showed a tumor volume increase >50% without a maximal diameter increase of ≥3 mm. The other four patients had both an increasing tumor volume and increasing maximal tumor diameter ≥3 mm. One patient (0.5%) had newly appeared cervical lymph node (LN) metastasis at 3 years after the initial diagnosis. There were no significant risk factors associated with increased tumor size, such as age, sex, or Hashimoto thyroiditis. Twenty-four patients (13%) underwent delayed thyroid surgery at a median of 31.2 months and seven (29%) had cervical LN metastasis on pathologic examination.

CONCLUSION

Some PTMCs could grow significantly after a relatively short period of active surveillance. We also found that the change in tumor volume was more sensitive to detect tumor progression than the change in the maximal tumor diameter.