Incidental and non-incidental thyroid microcarcinoma

Correlation of pN Stage and Hypoechogenicity with Tumour Encapsulation and Vascular Invasion in Thyroid Cancer (TC): A Comprehensive Analysis and Clinical Outcomes

In this retrospective study, the relationship between the pN stage of TC and the ultrasound hypoechogenicity of tumour encapsulation and vascular invasion was investigated. The data of a total of 678 TC patients were analysed. The goal of this study was to assess the significance of the pTNM score and preoperative ultrasound features in predicting cancer prognosis and guiding therapeutic decisions in patients with TC. The main research methods included a retrospective analysis of patient data, mainly the pTNM score and presence of tumour encapsulation and vascular invasion obtained from histopathological results and preoperative ultrasound imaging. Patients with well-differentiated TCs (papillary and follicular) were extracted from TC patients to better unify the results because of similar clinical strategies for these TCs. Significant associations were observed between advanced pN stage and the presence of encapsulation and vessel invasion. The majority of pN1a patients exhibited encapsulation (77.71%; p < 0.0001) and vascular invasion (75.30%; p < 0.0001), as did the majority of pN1b patients (100%; p < 0.0001 and 100%; p < 0.0001, respectively). Less than half of the patients with hypoeghogenic patterns presented with encapsulation (43.30%; p < 0.0001) and vascular invasion (43.52%; p < 0.0001), while the vast majority of patients without hypoechogenicity did not present with encapsulation (90.97%; p < 0.0001) or vascular invasion (90.97%; p < 0.0001). Hypoechogenicity was found to be indicative of aggressive tumour behaviour. The results of this study underscore the importance of accurate N staging in TC and suggests the potential use of ultrasound features in predicting tumour behaviour. Further research is needed to confirm these findings and explore additional prognostic markers to streamline TC management strategies and improve patient outcomes.

Papillary Thyroid Microcarcinoma: Differences between Lesions in Incidental and Nonincidental Settings-Considerations on These Clinical Entities and Personal Experience

Papillary thyroid microcarcinoma (PTMC) represents 35-40% of all papillary cancers; it is defined as a nodule ≤ 10 mm at the time of histological diagnosis. The clinical significance of PTMC is still controversial, and it may be discovered in two settings: incidental PTMC (iPTMC), in which it is identified postoperatively upon histological examination of thyroid specimens following thyroid surgery for benign disease, and nonincidental PTMC (niPTMC), in which it is diagnosed before surgery. While iPTMC appears to be related to mild behavior and favorable clinical outcomes, niPTMC may exhibit markers of aggressiveness. We retrospectively review our experience, selecting 54 PTMCs: 28 classified as niPTMC (52%) and 26 classified as iPTMC (48%). Patients with niPTMC showed significant differences, such as younger age at diagnosis (p < 0.001); a lower male/female ratio (p < 0.01); a larger mean nodule diameter (p < 0.001); and a higher rate of aggressive pathological findings, such as multifocality, capsular invasion and/or lymphovascular invasion (p = 0.035). Other differences found in the niPTMC subgroup included a higher preoperative serum TSH level, higher hospital morbidity and a greater need for postoperative iodine ablation therapy (p < 0.05), while disease-free long-term survival did not differ between subgroups (p = 0.331) after a mean follow-up (FU) of 87 months, with one nodal recurrence among niPTMCs. The differences between iPTMC and niPTMC were consistent: patients operated on for total thyroidectomy and showing iPTMC can be considered healed after surgery, and follow-up should be designed to properly calibrate hormonal supplementation; conversely, niPTMC may sometimes exhibit aggressive behavior, and so the FU regimen should be closer and aimed at early detection of cancer recurrence.

Clinicopathologic characteristics of incidental thyroid carcinoma in euthyroid patients receiving total thyroidectomy for multinodular goiter: A retrospective cohort study

BACKGROUND

Total thyroidectomy is the treatment of choice for multinodular goiter (MNG). In some of these cases, incidental thyroid cancer (ITC) is detected postoperatively. Papillary thyroid microcarcinoma (PTMC), the most common type of ITC, has clinical factors and pathologic similarities with ITC that have not been well clarified previously. We investigated the incidence and characteristics of ITC and PTMC in euthyroid patients undergoing total thyroidectomy for MNG.

METHODS

We retrospectively investigated the data of 151 euthyroid patients who underwent total thyroidectomy for MNG between January 2016 and December 2020. Patients with PTMC were then selected from among those with ITC for further data analysis.

RESULTS

The incidence rates of ITC and PTMC were 31.1% (47/151) and 21.1% (32/151), respectively. The mean age of patients with ITC was 52.8 ± 11.7 years, which was younger than that of patients with benign MNG (57.2 ± 12.5 years, p < 0.05). Bilateral cancer was observed in 17 patients with ITC (17/47, 36.2%) and nine with PTMC (9/32, 28.1%). The numbers of patients in the ITC and PTMC groups whose cancer was not on the side comprising the dominant tumor were 15 (15/47, 31.9%) and 13 (13/32, 40.6%), respectively. The multivariate analysis demonstrated that younger age was a clinical factor associated with ITC and PTMC.

CONCLUSION

Younger age is a clinical factor for ITC and PTMC. We recommend taking considering clinical factors and pathologic characteristics of ITC and PTC when considering total thyroidectomy in euthyroid patients with MNG.

Reclassification of papillary thyroid microcarcinoma (pMCT) according to the "Porto proposal" criteria

INTRODUCTION

pMCT is defined as a variant of papillary carcinoma that measures≤1 cm in diameter and which is characterized by an excellent prognosis. Recently, a proposal has been advanced to use the designation of papillary mirotumour (pMT) for pMCTs with no risk factors .

AIM

In this study, we aimed to reclassify pMCTs according to the Porto proposal(Pp) criteria.

METHODS

We have retrospectively collected cases of pMCT diagnosed in our pathology department over a period of 10years(2012-2022). Clinical and pathological parameters have been retrieved from the patient's medical records and pathological reports. We have evaluated all cases following the criteria of Pp. Cases that fulfilled all the criteria have been reclassified as pMT. We have briefly compared the clinical outcomes in both groups.

RESULTS

29 cases of pMCT was found. Mean age of patients was 46,6 years-old (17-67) with a female predominance (sex ratio=0,45). 23 cases of pMCT were incidentally discovered. The tumor was located in the right thyroid lobe in 15cases. The mean size of the tumor was 5,2mm. Multifocality was observed in 5 cases. A total of 17 cases could be classified as pMT according to the Pp. Only one patient developed pulmonary metastasis and local recurrence; however it was related to the papillary carcinoma firstly diagnosed in his contralateral lobe. Clinical outcome was also good in the group of papillary microcarcinoma (pMC) with no recurrence or distant metastasis.

CONCLUSION

According to the Pp,>50% of pMCT could be reclassified as pMT which could reduce the psychological impact and overtreatment. Further studies with large sample size and molecular analysis are however needed in order to definitively validate and generalize the use of Porto proposal.

Risk of Thyroid Cancer Associated with Use of Liraglutide and Other Antidiabetic Drugs in a US Commercially Insured Population

BACKGROUND

Quantify association between the glucagon-like peptide-1 receptor agonist liraglutide and risk of thyroid cancer (TC) compared to other antidiabetics.

PATIENTS AND METHODS

Initiators of liraglutide, exenatide, metformin, pioglitazone or groups of dipeptidyl peptidase-4 inhibitors or sulfonylureas were identified in a US health plan (2010-2014) and followed for a median of 17 months. Thyroid cancer cases during follow-up were identified via a validated algorithm. Incidence rates of TC among liraglutide and comparators were assessed using relative risks estimated within propensity score-matched cohorts using intention to treat (ITT) and time on drug analyses. Latency effects and potential surveillance bias were evaluated.

RESULTS

Relative risks from ITT analyses ranged from 1.00 (95% confidence interval (CI) 0.56-1.79) versus metformin to 1.70 (95% CI 1.03-2.81) versus all comparators excluding exenatide. Effect estimates from latency analyses were slightly attenuated. Time on drug analyses suggested no increased risk for either longer duration or higher cumulative dose of liraglutide. Medical record review found 85% were papillary or a follicular variant of papillary or both; 46% were microcarcinomas (≤10 millimeters), which were more prevalent in the liraglutide cohort (67% versus 43% in all comparators).

CONCLUSION

Relative risks were elevated for several comparisons, which should be interpreted cautiously because of potential residual confounding and surveillance bias. Liraglutide cases had smaller thyroid nodules and shorter time-to-diagnosis, suggesting increased surveillance for TC among liraglutide initiators, especially shortly after the drug´s approval. After adjusting the primary analyses (ITT) for latency, no significant elevated risk of TC was observed among liraglutide initiators.

Thyroid Papillary Microtumor: Validation of the (Updated) Porto Proposal Assessing Sex Hormone Receptor Expression and Mutational BRAF Gene Status

Given the high incidence and excellent prognosis of many papillary thyroid microcarcinomas, the Porto proposal uses the designation papillary microtumor (PMT) for papillary microcarcinomas (PMCs) without risk factors to minimize overtreatment and patients' stress. To validate Porto proposal criteria, we examined a series of 190 PMC series, also studying sex hormone receptors and BRAF mutation. Our updated Porto proposal (uPp) reclassifies as PMT incidental PMCs found at thyroidectomy lacking the following criteria: (a) detected under the age of 19 years; (b) with multiple tumors measuring >1 cm adding up all diameters; and (c) with aggressive morphologic features (extrathyroidal extension, angioinvasion, tall, and/or hobnail cells). PMCs not fulfilling uPp criteria were considered "true" PMCs. A total of 102 PMCs were subclassified as PMT, 88 as PMC, with no age or sex differences between subgroups. Total thyroidectomy and iodine-131 therapy were significantly more common in PMC. After a median follow-up of 9.6 years, lymph node metastases, distant metastases, and mortality were only found in the PMC subgroup. No subgroup differences were found in calcifications or desmoplasia. Expression of estrogen receptor-α and estrogen receptor-β, progesterone receptor, and androgen receptor was higher in PMC than in nontumorous thyroid tissue. BRAF mutations were detected in 44.7% of PMC, with no differences between subgroups. In surgical specimens, the uPp is a safe pathology tool to identify those PMC with extremely low malignant potential. This terminology could reduce psychological stress associated with cancer diagnosis, avoid overtreatment, and be incorporated into daily pathologic practice.

Analysis of Malignant Thyroid Neoplasms with a Striking Rise of Papillary Microcarcinoma in an Endemic Goiter Region

According to National Cancer Registry Program, Thiruvananthapuram district of Kerala, has the highest relative frequency of thyroid carcinomas; nevertheless, limited data exist regarding its socio-demographic and clinico-pathological characteristics. The aims of the study were to assess the: (1) demographic characteristics, (2) histopathological features and the relative frequency of various thyroid carcinoma cases and papillary thyroid carcinoma (PTC) subtypes, (3) rising trend of papillary microcarcinomas, and (4) associated lesions. A retrospective study wherein 170 cases of thyroid malignancies reported in our single institution over a period of 8 years period was reviewed. PTC accounted for 97% cases, followed by medullary (n = 4; 2.4%) and follicular carcinoma (n = 1; 0.6%). There was female preponderance (p = 0.0379) with a lower median age in females (p = 0.0275). Among the PTCs, conventional type constituted 53.4% cases (n = 87), followed by microcarcinomas (n = 34; 20.9%), follicular variant (n = 28; 17.2%), and others 14 cases (8.5%). Thirty-three cases (19.4%) showed multifocality, 5 cases (2.9%) extra-thyroid extension, and 19 cases (11.2%) lymph node metastasis. Two cases developed recurrences and three cases, metastasis. The associated lesions were significantly higher in females (p = 0.0059); most common being multinodular goiter (MNG; n = 67; 41.1%), followed by Hashimoto thyroiditis (n = 44; 27%) and lymphocytic thyroiditis (n = 28; 17.2%); MNG being associated with follicular (p = 0.0129), and Hashimoto thyroiditis with conventional variant (p = 0.0475). The frequency of microcarcinomas significantly increased in the past 4 years (p = 0.0291) and was associated with MNG (p = 0.0055), Hurthle cell nodule (p = 0.0315) and absent lymph node metastasis (p = 0.0147). The primary treatment modality was total thyroidectomy. Papillary microcarcinoma cases increased significantly in the past 4 years and were significantly associated with MNG and Hurthle cell nodule. It is challenging to distinguish the various PTC subtypes as recognition of these histological variants warrants better patient management.

Papillary microcarcinoma of the thyroid gland: current controversies and management

PURPOSE OF REVIEW

To highlight recent advances in our understanding of the nature of micropapillary thyroid carcinoma (mPTC), its evaluation and options of management based on risk.

RECENT FINDINGS

A dramatic increase of the incidence of papillary thyroid carcinoma has been reported worldwide during recent decades, specifically those smaller than 10 mm (mPTC). Although not taking into consideration other risk factors for aggressiveness when describing tumours by their size, most of these newly diagnosed mPTC are indolent and active surveillance can be considered as valid option for their management.

SUMMARY

An increasing number of patients with mPTC will be encountered in clinical practice. Although it is difficult to assess the aggressiveness of a tumour on size criteria, less than a total thyroidectomy and active surveillance can be considered for the majority of patients with mPTC. Further trials should be performed to prove this as a valid option of management in the majority of these patients.

A cancer of undetermined significance: Incidental thyroid carcinoma

INTRODUCTION

The incidence of thyroid cancer is increasing which can be attributed in part to improved ultrasonography (US) methods and increased detection of incidental thyroid carcinomas (ITC). We aimed to compare ITC with nonincidental thyroid carcinomas (NITC) in this study.

METHODS

Retrospective analyses of 906 individual patients who were operated for benign and malignant thyroid disease and had a final histopathological diagnosis of thyroid carcinoma were enrolled in this study. Preoperative US examination and fine needle aspiration (FNA) biopsy results were evaluated. The tumor foci in thyroidectomy specimens that were not represented in preoperative US or FNA reports were classified as ITC. The tumor foci that match with the lesions defined in US or FNA results were classified as NITC.

RESULTS

Final histology revealed ITC in 326 patients (36%) and NITC in 580 patients (64% Mean age was 51.7 ± 11.11 in ITC group and 48.15 ± 13.1 in NITC group (P < .001). In NITC group 322 (55.5%) of the patients were operated for suspicious cytology while only 29 (8.9%) of the patients in the ITC group were operated because of this indication (P < .001). There were 1301 cancer foci in histopathology specimens. Among all these cancer foci, 434 (33.3%) were detected incidentally and 867 (66.7%) were detected non-incidentally. About 779 (89.9%) of nonincidental cancer foci were papillary cancer (PTC), while all of the incidental cancer foci were PTC. Mean size was 13 mm in NITC group and it was 3 mm in the ITC group and differed significantly between the groups (P < .001). Tumor size was ≤1 cm in 35.2% of the patients with NITC while 98.5% of patients with ITC had tumor ≤1 cm. The occurrence of multinodularity was higher in ITC than the NITC group (P < 001). Median TSH level was higher in patients with NITC than ITC while both were in the reference range (1.53 vs 1.03 μIU/mL, P < .001). The frequency of thyroiditis detected by US, and thyroid peroxidase antibody and thyroglobulin antibody positivities were similar in patients with ITC and NITC (P = .2, P = .86, and P = .26, respectively). The frequencies of capsular invasion (29.1% vs 7.9%), extrathyroidal extension (13% vs 4.2%), multifocality (35.8% vs 24.2%), non-complete resection (9.2% vs 1.8%), and lymph node metastasis (9.5% vs 1.8%) were significantly higher in the NITC group (P < .001, for each). Persistent/recurrent disease in patients with NITC was more frequent than patients with ITC (P = .004). This outcome was similar for cancers measuring ≤1 cm (P = .001).

CONCLUSION

ITC is often encountered in older patients and frequently determined in early stages with more favorable histopathological features and better prognosis.

Comparison of the prevalence of incidental and non-incidental papillary thyroid microcarcinoma during 2008-2016: a single-center experience

Background

The incidence of papillary thyroid microcarcinoma (PTMC) is increasing; however, it is not clear whether this reflects an increase in the incidence of incidental or in that of non-incidentally (presurgically) discovered PTMC (IPTMC vs. NIPTMC). We assessed the incidence of IPTMC and NIPTMC over the past 9 years, to discern whether the increase in PTMC incidence is due to improved diagnostics or to a real increase in the incidence.

Methods

We performed a retrospective chart review of 4327 patients who were consecutively admitted to and surgically treated for thyroid pathology at a single institution. As a main presurgical diagnostic test, all patients underwent ultrasound-guided fine-needle aspiration biopsy (UG-FNAB). The analyzed time frame was divided into three equal periods (I: 2008–2010, II: 2011–2013, III: 2014–2016), and IPTMCs and NIPTMCs were assessed and compared in each period.

Results

We evaluated 393 (9.08%) patients with thyroid malignancy, of which 156 (3.60% of all thyroid tumors [TTs]; 39.69% of all thyroid cancers [TCs]) were diagnosed as PTMC. The prevalence of NIPTMC among all TCs increased from 16.66% in 2008 to 33.75% in 2016, while that of IPTMC decreased from 20.83% in 2008 to 13.75% in 2016. The incidence rates of NIPTMC and IPTMC in period III differed statistically significantly (p < 0.0001). The prevalence rate of NIPTMC in period III was higher than that in period II, yet comparable to that in period I (p = 0.0014; p = 0.2804, respectively).

Conclusions

The prevalence of NIPTMC, rather than that of IPTMC, is escalating; this may be due to better presurgical diagnosis.

Diagnostic Accuracy of Preoperative Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios in Detecting Occult Papillary Thyroid Microcarcinomas in Benign Multinodular Goitres

Objective

To investigate the diagnostic accuracy of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios in detecting occult papillary thyroid microcarcinomas in benign, multinodular goitres.

Methods

397 total thyroidectomy patients were identified from the institutional thyroid surgery database between 2007 and 2016 (94 males, 303 females, mean age 53 ± 14.5 years). NLR and PLR were calculated as the absolute neutrophil and absolute platelet counts divided by the absolute lymphocyte count, respectively, based on the preoperative complete blood cell count.

Results

NLR was significantly higher in carcinomas and microcarcinomas compared to benign pathology (p = 0.026), whereas a direct association could not be established for PLR. Both NLR and PLR scored low in all parameters of diagnostic accuracy, with overall accuracy ranging between 45 and 50%.

Conclusions

As surrogate indices of the systemic inflammatory response, NLR and PLR are inexpensive and universally available from routine blood tests. Although we found higher NLR values in cases of malignancy, NLR and PLR cannot effectively predict the presence of occult papillary microcarcinomas in otherwise benign, multinodular goitres.

The first postoperative-stimulated serum thyroglobulin is a prognostic factor for thyroid microcarcinomas

INTRODUCTION

Endogenous thyroid-stimulating hormone-stimulated thyroglobulin collected after total thyroidectomy is a useful predictor of better prognosis in patients with differentiated thyroid carcinomas in general, but studies with microcarcinomas are scarce.

OBJECTIVE

To assess whether the first postoperative stimulated thyroglobulin measurement is a prognostic factor in patients with microcarcinoma.

METHODS

The medical data of 150 differentiated thyroid carcinoma patients were studied retrospectively, and 54 (36%) cases with microcarcinoma were selected. The first postoperative stimulated thyroglobulin (1st stimulated thyroglobulin), measured after thyroidectomy, initial presentation data, and microcarcinomas treatment were assessed regarding outcome. Worse prognosis was defined as neoplasm persistence/recurrence.

RESULTS

Persistence/recurrence occurred in 27.8% of the cases. These patients were identified according to the following parameters: receiving more than one ¹³¹iodine dose (100% vs. 0%; p<0.0001); accumulated ¹³¹iodine dose (232.14±99.09 vs. 144±33.61mCi; p<0.0001); presented active disease in the last assessment (53.3% vs. 0%; p<0.0001); follow-up time (103.07±61.27 vs. 66.85±70.14 months; p=0.019); and 1st stimulated thyroglobulin (19.01±44.18 vs. 2.19±2.54ng/dL; p<0.0001). After multivariate logistic regression, only the 1stSTg [odds ratio=1.242; 95% confidence interval: 1.022-1.509; p=0.029] and follow-up time (odds ratio=1.027; 95% confidence interval: 1.007-1.048; p=0.007) were independent predictors of risk of persistence/recurrence. The cutoff point of 1.6ng/dL for the 1st stimulated thyroglobulin was significantly associated with disease persistence/recurrence [area under the curve=0.713 (p=0.019)].

CONCLUSION

The first stimulated thyroglobulin predicted disease persistence/recurrence in patients with microcarcinoma.