The value of frozen section in intraoperative surgical management of thyroid follicular carcinoma

Development and validation of a population-based model for predicting the regional lymph node metastasis in adolescent differentiated thyroid carcinoma

BACKGROUND

Adolescent differentiated thyroid carcinoma (DTC) is a rare type of thyroid cancer that represents a special entity of all endocrine-related cancer. This study aims to establish the first nomogram for predicting the regional (central and lateral) lymph node metastasis (LNM) in the adolescent population for better surgical management.

METHOD

We retrospectively reviewed the clinicopathology characteristics of adolescent patients with DTC in the Surveillance, Epidemiology, and End Results database between 2010 and 2015.

RESULTS

A total of 1,930 adolescent patients between the ages of 10 and 24 years from the SEER database were enrolled in this study. Six predictive factors including age, race, histology, multifocality, extrathyroidal invasion (EI) and tumor size were identified to be significantly associated with the regional LNM via univariate and multivariate logistic regression analyses. These indicators were used to construct a nomogram for predicting the regional LNM in adolescent patients with DTC. Moreover, a satisfied predictive ability of the model was determined with a C-index of 0.794, supported by an internal validation group with a C-index of 0.776. The Decision Curve Analysis and calibration curve further conducted a great agreement in our model.

CONCLUSION

The first predictive model containing multiple factors has been successfully established with good discrimination for predicting the regional LNM in adolescent patients with DTC. This nomogram could effectively help surgeons to make better individualized surgical decision intraoperatively, especially in terms of whether cervical lymph node dissection (LND) is warranted.

2017 Thyroid Radiofrequency Ablation Guideline: Korean Society of Thyroid Radiology

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed recommendations for the optimal use of radiofrequency ablation for thyroid tumors in 2012. As new meaningful evidences have accumulated, KSThR decided to revise the guidelines. The revised guideline is based on a comprehensive analysis of the current literature and expert consensus.

Follicular thyroid cancer and Hürthle cell carcinoma: challenges in diagnosis, treatment, and clinical management

Follicular thyroid cancer is the second most common differentiated thyroid cancer histological type and has been overshadowed by its more common counterpart-papillary thyroid cancer-despite its unique biological behaviour and less favourable outcomes. In this Review, we comprehensively review the literature on follicular thyroid cancer to provide an evidence-based guide to the management of these tumours, to highlight the lack of evidence behind guideline recommendations, and to identify changes and challenges over the past decades in diagnosis, prognosis, and treatment. We highlight that correct identification of cancer in indeterminate cytological samples is challenging and ultrasonographic features can be misleading. Despite certain unique aspects of follicular thyroid cancer presentation and prognosis, no specific recommendations exist for follicular thyroid cancer and Hürthle cell carcinoma in evidence-based guidelines. Efforts should be made to stimulate additional research in this field.

Radiofrequency ablation of small follicular neoplasms: initial clinical outcomes

BACKGROUND

In thyroid gland, radiofrequency ablation (RFA) has been applied to both recurrent cancers and benign nodules, although, according to the American Thyroid Association (ATA) and the Korean Society of Thyroid Radiology (KSThR) guidelines, surgery is the first-line treatment for follicular neoplasm. However, it has been argued that follicular neoplasm with lower risk of malignancy can be managed by close follow-up. In this study, we evaluated the effectiveness of RFA of small follicular neoplasms, examining reductions in volume and related clinical problems, and making observations over long-term follow-up.

METHODS

We evaluated 10 follicular neoplasms in 10 patients who were treated with RF ablation between 2009 and 2011. A RF generator and an 18-gauge internally cooled electrode were used to perform complete ablation of the whole nodules. Changes in nodules or ablated zones on follow-up ultrasound, and complications during and after RF ablation were evaluated.

RESULTS

The mean follow-up period was 66.4 ± 5.1 months (range: 60-76 months). In eight patients, single session of RF ablation was sufficient, while two patients required two sessions. There was a significant reduction in the mean volume (99.5 ± 1.0%) of lesions, with eight ablated lesions (8/10, 80%) disappearing completely on follow-up. No recurrences were found in any ablated zones at last follow-up. Transient mild neck pain (n = 6) occurred during the procedure without requiring any medication.

CONCLUSION

In addition to active surveillance, RF ablation may be an effective and safe alternative for the management of patients with small (<2 cm) follicular neoplasm suspected on thyroid biopsy and who strongly refuse surgery.

Can Nodular Hyperplasia of the Thyroid Gland be Differentiated From Follicular Adenoma and Follicular Carcinoma by Ultrasonography?

OBJECTIVES

The aim of this study was to evaluate the ultrasonographic features for differentiation of follicular thyroid lesions.

METHODS

Ultrasonographic features of surgically confirmed 56 follicular adenoma (FA), 22 follicular carcinoma (FC), and 100 nodular hyperplasia (NH) were evaluated using univariable and multivariable multinomial logistic regression analyses, receiver operating characteristic analyses, and areas under the curve.

RESULTS

Tumor diameter, margin, echotexture, cystic changes, calcification, hypoechoic rim, and vascularity were significant on univariable analysis. On multivariable logistic regression analyses, tumor diameter (FA, P = 0.002; odds ratio [OR], 0.75; FC, P = 0.001; OR, 2.02), absence of cystic changes (FA, P = 0.127; OR, 2.21; FC, P ≤ 0.001; OR, 17.74), absence of spongiform appearance (FA, P = 0.234; OR, 0.31; FC, P < 0.001; OR,  1673.46), and peripheral vascularity (FA, P = 0.004; OR, 26.64; FC, P < 0.001; OR, 145060.38) differed significantly among the 3 follicular lesions, with NH as a reference. The areas under the curve for NH, FA, and FC were 0.844, 0.858, and 0.705, respectively, and diagnostic accuracy was 72.6%.

CONCLUSIONS

Tumor diameter, cystic changes, spongiform appearance, and peripheral vascularity differed significantly among follicular lesions. The diagnostic capability was moderate.

Treatment of thyroid follicular carcinoma

Differentiated thyroid carcinoma includes 2 different tumor types, papillary (PC) and follicular carcinoma (FC), and although similar, their prognosis is different. FC is uncommon, and this has led to it often being analyzed together with PC, and therefore the true reality of this tumor is difficult to know. As a result, the diagnostic and therapeutic management and the prognostic factors in differentiated carcinoma are more predictive of PC than FC. In this review we analyze the current state of many of the therapeutic aspects of this pathology. The best surgical technique and the usefulness of associated lymphadenectomy is also analyzed. Regarding post-surgical ablation with 131I, the indications, doses and usefulness are discussed. For the remaining therapies we analyze the few indications for radiotherapy and chemotherapy, and of new drugs such as tyrosine kinase inhibitors.

Better understanding in the differentiation of thyroid follicular adenoma, follicular carcinoma, and follicular variant of papillary carcinoma: a retrospective study

Background. To evaluate the role of ultrasonography (US), US-guided fine-needle aspiration (USFNA) and intraoperative frozen section (FS) in follicular neoplasm. Methods. US features, USFNA cytology, and FS results were compared based on the pathology results of patients with follicular adenoma (FA), follicular carcinoma (FC), and follicular variant of papillary thyroid carcinoma (FVPTC). Results. FC and FVPTC showed significantly higher rates of suspicious US features (P < 0.05) and positive findings on either US or cytology, 80.0% and 90.7%, compared to FA, 64.5% (P = 0.001). Intraoperative FS showed higher malignant rates in FVPTC and FC (81.8% and 75.0%, resp.), compared to FA (3.8%, P < 0.001). Conclusion. Suspicious US features were more significantly seen in FC and FVPTC compared to FA. Intraoperative FS is useful in the differential diagnosis of these lesions and supplements cytology results of USFNA.

Operative Decision-Making for Follicular Thyroid Lesions: A Community Hospital System Experience

Follicular neoplasms of the thyroid are a frequent indication for surgery of the thyroid gland. We evaluated the use of frozen sections on intraoperative decision-making, possible avoidance of reoperative surgery, and histologic findings in a retrospective cohort. A database was created of all thyroid operations from 2001 to 2007. Data collected included age, gender, preoperative cytology, indication for surgery, surgeon, intraoperative decision-making, and histologic findings. Of the 723 thyroidectomies, 203 were performed for follicular neoplasms diagnosed by fine needle aspiration. Of these, 135 had cytology reports available within our electronic medical record; 44 per cent (59 of 135) of these patients had an intraoperative frozen section. Only two of 59 (3.4%) were positive for carcinoma, both of which were papillary carcinomas. One was interpreted as “suspicious” for carcinoma by the pathologist. In these three cases, the surgeon proceeded with total thyroidectomy at the time of initial surgery. The results of frozen section altered the operation in only three of 59 cases (5.1%). Intraoperative frozen section rarely impacts the conduct of thyroidectomy for follicular neoplasms.

Thyroid follicular neoplasm: analysis by fine needle aspiration cytology, frozen section, and histopathology

We performed a retrospective analysis of follicular neoplasm data obtained from frozen section examinations of thyroid nodules. A total of 5,660 patients underwent preoperative neck ultrasonography and fine-needle aspiration cytology (FNAC), surgical treatment, and follow-up at a medical institute. Patients with papillary thyroid microcarcinoma were excluded from this study. In 971 cases, frozen section examination was performed during the surgical treatment of follicular neoplasm that was diagnosed via FNAC. Thyroid malignancies were histologically confirmed in 25.1% of cases (244/971). Among the patients with papillary thyroid carcinoma, 45 were diagnosed with the follicular variant of papillary thyroid carcinomas (27.4%). The diagnostic sensitivity of frozen section for the nonfollicular variant of papillary thyroid carcinoma was better than that for the follicular variant of papillary thyroid carcinoma (89.1% versus 78.9%; P = 0.1023). For 12 cases the diagnosis was atypical follicular adenomas. The diagnostic accuracy of frozen section in cases of follicular neoplasm was 76.9% with a sensitivity of 84.8% and a specificity of 98.9%. In conclusion, our analysis revealed high rates of accuracy when using frozen tissue sections for early diagnosis and treatment of follicular neoplasm; thus, an early decision to extent of surgery prevents a risky follow-up surgery.

Follicular thyroid carcinoma in an iodine-replete endemic goiter region: a prospectively collected, retrospectively analyzed clinical trial

OBJECTIVE

To determine risk factors for presence of lymph node or distant metastases in patients with follicular thyroid cancer (FTC) at the time of diagnosis and whether there is a relationship between the type of tumor invasion and metastases.

SUMMARY BACKGROUND DATA

FTC often presents distant metastases at the initial diagnosis. As distant metastases are independent prognostic factors in a patient's survival, determination of clinicopathologic characteristics for patients who are at higher risk for developing metastases is of greater clinical importance.

METHODS

The prognostic significance of gender (male vs. female), age (<or=40 years vs. <40 years), tumor size (<or=40 mm vs. >40 mm), number of lesions (uni- vs. multifocality), type of invasion (minimally invasive vs. widely invasive), and oncocytic changes (with vs. without) were analyzed in 207 patients, according to presence of lymph node and distant metastases at the time of initial surgery. According to the type of invasion, the carcinoma-specific survival and the disease-free survival of minimally invasive (MI) and widely invasive (WI) FTC were estimated and compared.

RESULTS

None of the 127 patients with MI growth presented with lymph node metastases but 9.4% distant metastases. Overall risk factors for the presence of lymph node metastases at the initial diagnosis were multifocality (P = 0.02) and widely invasion (P = 0.0001) and for distant metastases age >45 years (P = 0.007), tumor size larger than 40 mm (P = 0.03) and widely invasion (P = 0.0001).WI-FTC patients show larger tumors (P = 0.0001), older age (P = 0.0001), and are presented more frequently in recurrent goiter disease (P = 0.0001). The estimated 10 years carcinoma-specific survival and disease-free survival for MI-tumors were significantly better than for WI-tumors (P = 0.0001).

CONCLUSIONS

Total thyroidectomy is recommended in all patients with FTC because of early distant metastases. Patients with WI-FTC need a more aggressive surgical treatment because of higher tendency for lymph node metastases. MI-FTC has an excellent prognosis with no sign of lymph node metastases, which emphasizes a limited need for nodal surgery.

Intraoperative pathologic examination: cost effectiveness and clinical value in patients with cytologic diagnosis of cellular follicular thyroid lesion

OBJECTIVE

Routine use of intraoperative pathologic examination (IOPE), including frozen section (FS) and scrape preparation cytology (SPC), during diagnostic thyroid lobectomy continues to be a source of controversy. We sought to better delineate the usefulness and cost-benefit ratio of IOPE in the context of cytologically diagnosed cellular follicular lesion (CFL) or follicular neoplasm (FN).

DESIGN

Records of 205 patients who underwent thyroidectomy for cytologically diagnosed FN or CFL between 1997 and 2005 were retrospectively reviewed. IOPE results, patient demographics, and tumor characteristics were correlated to final histopathologic diagnoses. Sensitivity, specificity, predictive values, accuracy, and costs of IOPE were calculated.

MAIN OUTCOME

IOPE correctly identified 3 of 16 follicular carcinomas and 9 of 36 papillary carcinomas. Sensitivity, specificity, and accuracy were 23%, 99%, and 78%, respectively. On univariate analysis, malignancy risk among follicular nodules did not correlate with age, gender, or nodule size. On multivariate analysis, nodule size was predictive of malignancy (p < 0.05). Over the entire patient series, routine IOPE resulted in a net cost savings of $74,304.33.

CONCLUSIONS

IOPE reduced costs and limited the number of completion thyroidectomies necessary. IOPE is specific, cost effective, and of minimal additional risk when performed routinely for patients with CFL or FN.

Follicular thyroid carcinoma: From diagnosis to treatment

Unusual presentations with bone, lung or soft tissue metastases in initial diagnosis of follicular thyroid carcinoma have been reported occasionally. This implies how difficult it is to diagnosis this type of cancer at the pre-operative or intra-operative stage of treatment. Fine needle aspiration cytology has been shown to be an ineffective method for diagnosing vascular or capsule invasion of follicular thyroid cancer. Multiple frozen sections, usually 5 to 12 depending on the size of the tumor, can achieve a diagnostic accuracy of 98%. Clinical application of various gene expressions in thyroid follicular tumors by needle aspiration using in situ hybridization requires further investigation. Although radioactive iodide (131I) has been used as the standard treatment for follicular thyroid carcinoma with distant metastases, the effectiveness of 131I treatment for follicular thyroid carcinoma depends on the differentiation of cancer cells. The possibility of 131I for thyroid remnant ablation replacing a secondary operation for follicular thyroid carcinoma has been debated. Recent studies applied more expressions of sodium iodide symporters to attain the effect of 131I treatment and slow the proliferation of thyroid cancer cell which, in turn, slows the progression of follicular carcinoma. Consensus for the surgical procedures for the specific prognostic risks for follicular thyroid carcinoma is needed. Dedifferentiated, anti-angiogenic, or gene therapies for follicular thyroid cancer with distant metastases or anaplastic transformation comprise the principal directions in future research for this cancer.

PPARgamma staining as a surrogate for PAX8/PPARgamma fusion oncogene expression in follicular neoplasms: clinicopathological correlation and histopathological diagnostic value

The PAX8/PPARgamma (PPFP) fusion-oncogene is moderately specific for follicular thyroid carcinomas (FTC). It remains unknown whether this can be translated into improved diagnosis, classification, or outcome prediction. We studied a cohort of well-characterized follicular adenomas (FA), FTC, and Hurthle cell carcinomas (HCC) from patients with complete clinical follow-up, to determine whether PPARgamma immunohistochemistry (as a surrogate of PAX8/PPARgamma expression) helps to distinguish FA from FTC and to assess its diagnostic accuracy as an adjunct to frozen section. We also correlated PPARgamma staining with clinical outcomes to assess its role as a prognostic marker.PPARgamma staining was more common in FTC (31 of 54; 57%) than in HCC (one of 23; 4%) or FA (four of 31; 13%) (P < 0.000001). Adjunctive use of PPARgamma immunohistochemistry improved diagnostic sensitivity of intraoperative frozen section from 84% to 96% (P < 0.05) but reduced specificity from 100% to 90% (P < 0.05). PPARgamma staining was associated with favorable prognostic indicators (female gender, better tumor differentiation, and lesser risk of metastases).PPARgamma staining may be helpful in the differential diagnosis of FA, FTC, and HCC, particularly when diagnostic sensitivity of histomorphology is reduced (e.g. during intraoperative frozen section). PPARgamma staining also shows an association with favorable prognosis and may have a role in risk stratification.