Risk of Malignancy (ROM) of Thyroid FNA Diagnosed as Suspicious for Malignancy or Malignant: an Institutional Experience with Systematic Review and Meta-Analysis of Literature

Operation rate and cancer prevalence among thyroid nodules with FNAC report of suspicious for malignancy (TIR4) or malignant (TIR5) according to Italian classification system: a systematic review and meta-analysis

BACKGROUND

In the Italian system for reporting thyroid cytology (ICCRTC), nodules suspicious for (TIR4) and consistent with (TIR5) malignancy are thought being 5% and 4-8% of all biopsies and having risk of malignancy of 60-80% and >95%, respectively. However, no evidence-based data exist about these figures. The present systematic review aimed at achieving solid estimates about TIR4 and TIR5 also considering potential influencing factors.

METHODS

The review was conducted according to MOOSE. Databases of Google Scholar and Cochrane were searched. No language restriction was used. The last search was performed on February 26th 2022. Quality assessment was performed. Proportion meta-analyses were performed using random-effect model. Statistical analyses were performed using OpenMeta [Analyst].

RESULTS

The online search retrieved 271 articles and 16 were finally included for quantitative analysis. The risk of bias was generally low. The pooled cancer prevalence in TIR4 was 92.5% (95%CI 89.4-95.6%) with unexplained moderate heterogeneity. The pooled cancer rate among TIR5 was 99.7% (95%CI 99.3-100%) without heterogeneity. The resection rate in TIR4 and TIR5 showed heterogeneity, being the latter explained when using their prevalence among biopsies: the higher the prevalence, the higher the operation rate. The pooled risk difference between TIR5 and TIR4 was significant (OR 11.153).

CONCLUSIONS

These figures can form the basis for the next updated version of ICCRTC. Any institution using ICCRTC should revise its series of TIR4/TIR5 to calculate the cancer rate, and, importantly, consider the modifiers of the risk of malignancy. A cross check among institutions is advised.

Multifocal Fibrosing Thyroiditis: an Under-recognized Mimicker of Papillary Thyroid Carcinoma

Multifocal fibrosing thyroiditis (MFT) is an enigmatic entity, characterized by multiple fibrotic scar-like lesions with a paucicellular fibrotic center surrounded by a cellular peripheral area with reactive-appearing follicular cell atypia and variable chronic inflammation. Although poorly recognized and likely underreported in surgical pathology, the entity is considered rare with only 65 cases to date-including the current one reported to expand on the preoperative findings of this under-recognized entity. The average age of the patients is 46.8 years (range 15-71 years), 94% are female, with female to male ratio of 15:1. Individual MFT lesions typically have a superficial location. The average number of fibrotic lesions is 15.4 (range 2-51 per MFT case). Their average size is 3.1 mm (range 0.4-15.1). MFT is a disorder of diseased thyroids, typically found postoperatively in glands removed for other reasons, such as chronic lymphocytic/Hashimoto thyroiditis (32.3%), follicular nodular disease (nodular hyperplasia) (30.1%), hyperthyroidism/diffuse hyperplasia (Graves disease) (9.2%). Intriguing is the association with papillary thyroid carcinoma-present in 38.5% of MFT cases, and particularly with sub-centimetric and multifocal papillary thyroid carcinoma, with which MFT can be confused. Cases where MFT is the only thyroid pathology (7.7%) can be preoperatively mistaken for papillary thyroid carcinoma, due to worrisome ultrasound (US) and cytologic features, both of which are here documented for the first time as a component of this article. Wider recognition of MFT and of its cytologic and ultrasound features at preoperative evaluation may reduce unnecessary thyroidectomies.

Reporting Thyroid Cytology in a Globalized World

The Italian SIAPEC-AIT 2014 classification, the 2017 Bethesda System for Reporting Thyroid Cytology (TBSRTC), the 2016 UK Royal College of Pathologists (RCPath) thyroid reporting system, and the 2019 Japanese reporting system for thyroid aspiration cytology (JRSTAC2019) represent the most widely used reporting systems among clinicians and pathologists for the purpose of cytologically diagnosing, estimating the potential risk of malignancy (ROM), and defining the most appropriate treatment for a patient with a thyroid nodule. Although all the systems use overlapping diagnostic categories and morphologic criteria, they differ on the basis of the criteria for inclusion in the cytologic categories, which may, in turn, affect the ROM of a given category and the clinical management of the patient, particularly with regard to the “indeterminate” categories. The aim of this review is to analyze the main differences that emerge between the systems and to propose possible solutions for a comprehensive reporting system that integrates and harmonizes all the criteria of the Italian classification and the Bethesda system, also taking into account the impact that the new tumor entity NIFTP (non-invasive follicular tumor with papillary-like nuclear features) that has, in many instances, replaced the non-invasive form of the follicular variant of papillary carcinoma, has had on the modification of malignancy risks.

2D vs 3D laparoscopic right colectomy: A propensity score-matching comparison of personal experience with systematic review and meta-analysis

BACKGROUND

The benefits of laparoscopic approach for right colectomy have been well established. However, the technical difficulty to construct the intra-corporeal anastomosis is still cumbersome.

AIM

To analyze the results of 3D and 2D laparoscopic right colectomy and to compare it to the published series through a systematic review and meta-analysis.

METHODS

A retrospective study with propensity score matching analysis of patients undergoing laparoscopic right colectomy at Umbria2 Hospitals from January 2014 to March 2020 was performed. A systematic review was accomplished comparing 2D and 3D right colectomy.

RESULTS

In the personal series 47 patients of the 2D group were matched to 47 patients of the 3D group. The 3D group showed a favorable trend in terms of mean operative time (170.7 ± 32.9 min vs 183.8 ± 35.4 min; P = 0.053) and a significant lower anastomotic time (16.9 ± 2.3 min vs 19.6 ± 2.9 min, P < 0.001). The complete mesocolic excision (CME) subgroups analysis showed a shorter anastomotic time (16.5 ± 1.8 min vs 19.9 ± 3.0 min; P < 0.001) and operative time (175.0 ± 38.5 min vs 193.7 ± 37.1 min; P = 0.063) in the 3D group. Six studies and our series were included in the meta-analysis with 551 patients (2D group: 291; 3D group: 260).The pooled analysis demonstrated a significant difference in favour of the 3D group regarding the operative time (P < 0.001) and the anastomotic time (P < 0.001) while no differences were identified between groups in terms of blood loss (P = 0.827), LNH yield (P = 0.243), time to first flatus (P = 0.333), postoperative complications (P = 0.718) and length of stay (P = 0.835).

CONCLUSION

The meta-analysis results showed that 3D laparoscopic right colectomy shortens operative and anastomotic time without affecting the standard lymphadenectomy. In our series, the advantage of the 3D system becomes evident when CME and/or more complex associated procedure are requested significantly reducing both the total operative and the anastomotic time.

Thyroid FNA terminology: The case for a single unified international system for thyroid FNA reporting

The use of reporting terminologies for thyroid FNA cytology enables standardisation and international alignment of the reporting of thyroid cytology results, which is essential. There are currently three major internationally recognised systems: Bethesda (TBS), UK RCPath (Thy), and Italian (TIR). A fourth terminology system used in Japan has identical categories to TBS but with different nomenclature. The aim of this review is to discuss the strengths and weaknesses of the TBS, UK RCPath, and TIR systems, and to make the case for international terminology harmonisation and standardisation.

Radiomics Analysis of [18F]-Fluorodeoxyglucose-Avid Thyroid Incidentalomas Improves Risk Stratification and Selection for Clinical Assessment

Background: [¹⁸F]-Fluorodeoxyglucose (FDG)-avid thyroid lesions incidentally detected on positron emission tomography/computed tomography (PET/CT) scans represent a tumor lesion in about 30% of cases. The present study evaluated the ability of PET metrics and radiomics features to predict final diagnosis of [¹⁸F]FDG thyroid incidentalomas (TIs). Methods: A total of 104 patients with 107 TIs were retrospectively studied; 30 nodules (28%) were diagnosed as malignant. After volumetric segmentation of each thyroid lesion, metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized uptake values (SUVs), and metabolic heterogeneity were estimated, and 107 radiomics features were extracted following a standard protocol. Results: MTV, TLG, SUVmax, SUVmean, and SUVpeak among functional PET parameters, and gray-level co-occurrence matrix (GLCM)_InverseDifferenceMoment, shape_Sphericity, GLCM_SumSquares, firstorder_Maximum2DDiameterSlice, firstorder_Energy, and GLCM_Contrast among nonredundant radiomics features, showed significantly different values between malignant and benign TIs (Mann-Whitney U-test, p < 0.01 for all). Univariate logistic regression revealed that these parameters demonstrated good ability to predict final diagnosis of TIs (p < 0.02 for all). Shape_Sphericity was the best predictor classifying 82% of TIs correctly (p < 0.0001). Only TLG, SUVmax, and shape_Sphericity retained significance (p < 0.0001) by multivariate analysis. Malignant lesion prevalence increased from 7% to 100% in accordance with the number (score, 0-3) of the three positive parameters present (χ² trend, p < 0.0001). A score of 0 excludes malignant TIs with a negative predictive value of 93%, while a score of 3 predicted malignancy with a positive predictive value of 100%. Conclusions: PET metrics and radiomics analysis can improve identification of [¹⁸F]FDG-avid TIs at high risk of malignancy. A model based on TLG, SUVmax, and shape_Sphericity may allow prediction of a final diagnosis, providing useful information for the management of TIs.

Exploring the Inter-observer Agreement Among the Members of the Italian Consensus for the Classification and Reporting of Thyroid Cytology

Classification schemes for reporting thyroid cytology of fine needle aspiration (FNA) of thyroid nodules are largely used in clinical practice, but the level of inter-observer agreement among cytopathologists is poorly acknowledged. The present study aimed to explore the inter-observer agreement among the experienced authors of the 2014 Italian Consensus for Classification and Reporting of Thyroid Cytology (ICCRTC). A stratified randomization was performed in order to obtain a sample homogeneously distributed and representative of all ICCRTC classes. Four high-experience raters were randomly selected among the extensors of the Italian consensus. They independently reviewed 60 FNA samples blindly of the initial cytological report and clinical features. Their overall agreement was evaluated according to Fleiss' kappa. The overall inter-observer agreement was moderate (κ 0.46). Specifically, a good agreement was found when the samples were consistent for malignancy (TIR5) or were not adequate for diagnosis (TIR1) (κ 0.67 and κ 0.73, respectively). A moderate agreement was present for suspicious-for-malignant category (TIR4), and a fair agreement was recorded in the two intermediate ones (TIR3A and TIR3B) (κ 0.36 and κ 0.35, respectively). For clinical purposes, the agreement was good (κ 0.74) in differentiating cases with surgical indication (TIR4/TIR5) from those in which surgery is not essential or requires limited extension (TIR3B/TIR3A/TIR2). In conclusion, the present study confirms the reliability of ICCRTC. These data represent a reference for cytopathologists using this system and are useful for the practice of clinicians and surgeons.

Ultrasound systems for risk stratification of thyroid nodules prompt inappropriate biopsy in autonomously functioning thyroid nodules

OBJECTIVE

Ultrasound (US) risk stratification systems (RSSs) have been developed to reduce the number of unnecessary fine-needle aspiration (FNA) biopsies in patients with thyroid nodules. Autonomously functioning thyroid nodules (AFTN) account for 5%-10% of palpable lesions and are very rarely malignant. The present study was undertaken to investigate how RSSs classify AFTNs and whether RSSs are able to avoid unnecessary FNA biopsies in such cases.

METHODS

Patients with AFTN who had undergone US, scintigraphy and thyroid function evaluation from December 2016 to December 2017 were selected. US images were retrospectively reviewed and AFTN reclassified according to AACE/ACE/AME, ACR-TIRADS, ATA, BTA, EU-TIRADS, K-TIRADS and TIRADS. Risk class and indication for FNA were assessed.

RESULTS

A number of 87 AFTNs from 85 consecutive patients were enrolled. A median diameter of 22 mm (range 10-59) was found, with an ovoid isoechoic nodule being the most frequent US presentation. When AFTNs were reclassified according to US RSSs, the most common categories were low and intermediate risk. AFTNs were assessed as being at high risk/high suspicion/malignant in 1%-9%, with good agreement among AACE/ACE/AME, ATA, EU-TIRADS, K-TIRADS and TIRADS. Remarkably, FNA was indicated in 27%-90% of AFTNs. A statistically significant difference among the systems was found; 8% of cases were nonclassifiable by one or more US RSS.

CONCLUSIONS

Ultrasound RSSs prompt inappropriate FNA in a significant number of patients with AFTN.