Poorly differentiated thyroid carcinoma arising from substernal goiter: a case report

Introduction and importance

Poorly differentiated thyroid carcinomas represent a rare heterogeneous group of malignant tumors that constitute ~2-4% of all thyroid neoplasms. Substernal goiter (SG) is defined as an enlargement of the thyroid gland that is located below the thoracic inlet. Malignant neoplasms arising from a SG were reported in only 2-3% of cases.This case report has been reported in line with the Surgical CAse REport (SCARE) Criteria.21.

Case presentation

This article presents a 54-year-old Syrian female who presented at our institution due to dysphagia, dyspnea, cervical swelling, and loss of appetite. Following clinical and radiological examinations, total thyroidectomy with lymph node dissection was performed. Microscopic examination revealed an infiltrative growth pattern of insular, trabecular, and solid formations of epithelial cells with scant eosinophilic cytoplasm, hyperchromatic nuclei, and bizarre mitotic figures with areas of necrosis. Subsequently, the final diagnosis was confirmed as a multifocal poorly differentiated thyroid carcinoma arising from a SG.

Clinical discussion

The heterogeneity of histologic features of poorly differentiated thyroid carcinoma represents a diagnostic challenge. Diagnosis of poorly differentiated thyroid carcinomas is based on the Turin Criteria, which highlights histopathological features. Computed tomography plays a major role in SG for further evaluation.

Conclusion

In this manuscript, the authors aimed to present a unique case report with challenging diagnostic features including the rapid development of an infiltrative poorly differentiated thyroid carcinoma from a SG highlighting the importance of a detailed histopathological examination of thyroid nodules in the absence of significant medical history.

Anaplastic and poorly differentiated thyroid carcinomas: genetic evidence of high-grade transformation from differentiated thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is the most advanced and aggressive thyroid cancer, and poorly differentiated thyroid carcinoma (PDTC) lacks anaplastic histology but has lost architectural and cytologic differentiation. Only a few studies have focused on the genetic relationship between the two advanced carcinomas and coexisting differentiated thyroid carcinomas (DTCs). In the present study, we investigated clinicopathologic features and genetic profiles in 57 ATC and PDTC samples, among which 33 cases had concomitant DTC components or DTC history. We performed immunohistochemistry for BRAF V600E, p53, and PD-L1 expression, Sanger sequencing for TERT promoter and RAS mutations, and fluorescence in situ hybridization for ALK and RET rearrangements. We found that ATCs and PDTCs shared similar gene alterations to their coexisting DTCs, and most DTCs were aggressive subtypes harboring frequent TERT promoter mutations. A significantly higher proportion of ATCs expressed p53 and PD-L1, and a lower proportion expressed PAX-8 and TTF-1, than the coexisting DTCs. Our findings provide more reliable evidence that ATCs and PDTCs are derived from DTCs.

Expanding Our Knowledge of DICER1 Gene Alterations and Their Role in Thyroid Diseases

Mutations in DICER1, a gene involved in RNA interference, have been associated with a wide range of multi-organ neoplastic and non-neoplastic conditions. Historically known for its association with pleuropulmonary blastoma, DICER1 syndrome has received more attention due to the association with newly discovered diseases and tumors. Recent studies evaluating DICER1 mutations and DICER1-driven thyroid disease in both pediatric and adult thyroid nodules revealed thyroid disease as the most common manifestation of DICER1 mutations. This study undertakes a comprehensive investigation into DICER1 mutations, focusing on their role in thyroid diseases. Specific attention was given to thyroid follicular nodular disease and differentiated thyroid carcinomas in infancy as highly indicative of germline DICER1 mutation or DICER1 syndrome. Additionally, poorly differentiated thyroid carcinoma and thyroblastoma were identified as potential indicators of somatic DICER1 mutations. Recognizing these manifestations should prompt clinicians to expedite genetic evaluation for this neoplastic syndrome and classify these patients as high risk for additional multi-organ malignancies. This study comprehensively synthesizes the current knowledge surrounding this genetically associated entity, providing intricate details on histologic findings to facilitate its diagnosis.

Werner syndrome associated with poorly differentiated thyroid carcinoma and systemic sclerosis-like skin manifestations: A case report

Werner syndrome (WS) is an autosomal recessive disorder characterised by premature ageing. WS patients often experience scleroderma-like manifestation including skin sclerosis and skin ulcer, making it difficult to differentiate WS from systemic sclerosis (SSc). Moreover, there is a high incidence of malignancy and arteriosclerosis-related disease in WS patients. We herein describe a 36-year-old woman with WS who had poorly differentiated thyroid carcinoma, one of the rare phenotypes of thyroid tumour. This case suggested the importance to distinguish WS from SSc and early diagnosis of malignancy.

Downhill Varices in the Hypopharynx of a Patient with a Large Thyroid Tumor: A Case Report

Downhill varices are usually caused by superior vena cava (SVC) obstruction due to bronchogenic carcinoma or mediastinal tumors. These structures exhibit retrograde blood flow and are located in the proximal esophagus. Varices in the hypopharynx resulting from mediastinal thyroid tumor are extremely rare. A 70-year-old man with a 35-year history of a growing thyroid tumor on the right side of his neck visited a local hospital. Fine-needle aspiration cytology of the tumor revealed benign goiter. Contrast-enhanced computed tomography showed a huge tumor (13 × 10 × 5 cm) in the right to left lobe of the thyroid that extended into the mediastinum. A well-enhanced mass mimicking hypopharyngeal cancer was identified in the hypopharynx. Endoscopic examination showed varices in the postcricoid region, so biopsy was contraindicated. The preoperative diagnosis was adenomatous goiter and hypopharyngeal varices caused by obstruction of the internal jugular and brachiocephalic vein by the goiter. Total thyroidectomy was performed and the hypopharyngeal varices had disappeared by the next day. The histopathological diagnosis of the thyroid tumor was poorly differentiated carcinoma. Mediastinal thyroid tumor rarely causes downhill varices due to SVC obstruction. However, signs of SVC obstruction were absent in this case, and varices were present in the hypopharynx, not in the upper esophagus. Obstructed venous flow from the thyroid plexus might circulate via the superior laryngeal vein and cause varices in the postcricoid region. When a patient with a large mediastinal tumor has a tumor-like lesion in the hypopharynx, downhill varices should be considered before scheduling a biopsy.

An Extremely Rare Case of Poorly Differentiated Thyroid Carcinoma Arising in Malignant Struma Ovarii and Concurrent Papillary Thyroid Carcinoma: A Case Study

Ovarian tumors can be classified by their origin - epithelial tumors, germ cell tumors, and stromal tumors. Malignant struma ovarii (MSO) are 0.01% of all ovarian tumors. In order to be classified as a struma ovarii, more than 50% of the teratoma consists of thyroid tissue. The thyroid tissue in the struma ovarii exhibits the same histological and physiological properties as that of the cervical thyroid tissue. Poorly differentiated thyroid carcinoma (PDTC) is an extremely rare occurrence when arising from an MSO. Including this case report, there are only 10 reports of PDTC in the setting of MSO. Of these cases, this patient is the only one who presented with concurrent primary thyroid carcinoma (PTC). This case study examines how invaluable intra-professional collaboration is for appropriate diagnosis, along with attention to detail of identifying markers in pathology sections and use of the appropriate immunohistochemical analysis.

Predictive factors and clinicopathological characteristics of outcome in poorly differentiated thyroid carcinoma: a single-institution study

Objective

To elucidate the clinicopathological characteristics and prognostic factors of poorly differentiated thyroid carcinoma.

Method

A total of 24912 thyroid carcinoma patients admitted to the First Medical Center of Chinese People's Liberation Army General Hospital from 2005 to 2020 were retrospectively reviewed. A total of 94 patients (39 males and 55 females, a male-female ratio of 1:1.4) fulfilled the selection criteria. Of these, 73 patients had undergone surgery. The clinical and pathological data were collected from each enrolled patient. Univariate and multivariate Cox regression analyses were performed to determine independent prognostic factors. All analyses were performed with the SPSS version 26.0 and R version 1.2.5033 in the R Studio environment.

Results

The specimens included 20 cases of poorly differentiated thyroid carcinoma complicated with papillary thyroid carcinoma, 17 cases complicated with follicular thyroid carcinoma, 34 cases complicated with other pathological types and 23 with a separate entity. The patient demonstrated a large age span, median age was 57 years (range 8-85 years, average 55.20 ± 15.74 years). The survival time of the 94 cases was calculated, and the mean Overall survival time was 33 (range, 1-170) months, and the mean Recurrence-free survival time was 14 (range, 1-90) months. Recurrence-free mortality is related to the age at diagnosis, extrathyroidal extension and Associated thyroid cancer (p<0.05). In contrast, overall mortality is related to the age at diagnosis, sex, extrathyroidal extension, T stage (AJCC 8th), surgery and radiation (p<0.05).

Conclusion

Middle-aged and elderly patients are still at high risk for poorly differentiated thyroid carcinoma. The pathologic results of poorly differentiated thyroid carcinoma are varied, and reasonable treatment has an important impact on the prognosis of poorly differentiated thyroid carcinoma.

An Unexpected Finding of Poorly Differentiated Thyroid Carcinoma in a Toxic Thyroid Nodule

Poorly differentiated thyroid carcinoma (PDTC) is a rare entity of thyroid cancer with an intermediate clinical behavior between differentiated and anaplastic thyroid cancer. Here we present a patient who was referred to the endocrinology clinic for evaluation of hyperthyroidism and multinodular goiter. Due to presence of right toxic thyroid nodules and compressive symptoms, the patient underwent right lobectomy and isthmectomy, where surgical pathology revealed PDTC in the right thyroid lobe. Based on this unusual case of malignancy within a toxic nodule, we propose further evaluation of hot nodules with concerning features such as growth rate. Furthermore, exploration of relative sodium iodine symporter (NIS) expression in PDTC may help us better understand how iodine uptake changes as PDTC develops, which may impact our approach to assessing and treating PDTC in the future.

Unusual Clinical Manifestations of Thyroid Carcinoma

Thyroid cancer is considered the most common endocrine malignancy, with the most frequent presentation of differentiated thyroid cancer being a neck swelling or an incidental finding of a thyroid nodule on imaging. In this case series, we describe three cases of thyroid cancer with unusual clinical manifestations. The first case describes a patient who underwent parathyroidectomy for primary hyperparathyroidism and was found to have papillary thyroid cancer on a cervical lymph node biopsy. While this may be coincidental, the literature raises the question of whether there may be an association. The second case describes a patient who presents with a suspicious thyroid nodule and was subsequently diagnosed with follicular thyroid cancer on biopsy. This raises the question of performing thyroidectomy early in patients with a suspicious thyroid nodule but a false negative biopsy. The third case describes a patient with a scalp lesion found to have poorly differentiated thyroid carcinoma, a rare presentation of this form of cancer.

Outcomes of lenvatinib therapy in poorly differentiated thyroid carcinoma

Background and objective

Lenvatinib showed promising results in a subgroup of patients with poorly differentiated thyroid carcinoma (PDTC) in the SELECT trial. Our aim was to report the effectiveness and tolerability of lenvatinib in our series of PDTC patients.

Methods

Medical records of eight consecutive patients with PDTC treated with lenvatinib in a single center between January 2019 and October 2022 were retrospectively reviewed. Inclusion criteria were PDTC diagnosis based on Turin criteria and evidence of disease progression in the previous 6 months.

Results

Eight PDTC patients received an average dose of lenvatinib of 18.1 mg for a median duration of treatment of 10.3 months. The baseline Eastern Cooperative Oncology Group performance status was ≥2 in 50% of patients. Two patients had unresectable primary tumor. Seven patients showed extrathyroidal disease, particularly mediastinal lymph nodes (85.7%), lung (71.4%), and bone (71.4%). The disease control rate was 100%, with partial response and stable disease in 12.5 and 87.5%, respectively. The median time to best overall response was 3 months, and the median duration of response was 7.5 months. Median progression-free survival was 12 months and median overall survival was not reached. At 6, 12, and 18 months, overall survival was 87.5, 71.4, and 57.1%, respectively. All patients experienced drug-related adverse effects (AEs). Four (50%) had dose reductions and two (25%) had temporary treatment interruptions. Lenvatinib was stopped in two patients due to grade ≥3 AEs.

Conclusion

Lenvatinib is an effective treatment for real-world PDTC patients. Adequate management of comorbidities and AEs increases treatment tolerability and minimizes dose reductions.

PD-L1 expression in rare and aggressive thyroid cancers: A preliminary investigation for a role of immunotherapy

Background and Aim

Programmed cell death ligand-1 (PD-L1) immunoexpression status determines the response to immunotherapy in many cancers. Limited data exist on PD-L1 status in aggressive thyroid tumors. We investigated PD-L1 expression across thyroid cancers and correlated it with their molecular profile.

Materials and Methods

Sixty-five cases of differentiated thyroid carcinoma, poorly differentiated thyroid carcinoma (PDTC), and anaplastic thyroid carcinoma (ATC) were assessed for PD-L1 expression (clone SP263, VENTANA). The differentiated cases encompassed the aggressive hobnail and tall cell subtypes of papillary thyroid carcinoma (PTC) besides classical PTC and follicular thyroid carcinoma (FTC). Ten nodular goiters (NG) were also evaluated. Tumor proportion score (TPS) and H-score were calculated. BRAF^V600E and H-/K-/N-RAS were assessed using allele-specific real-time polymerase chain reaction (PCR). Fisher's exact and Kruskal-Wallis tests were used to investigate the associations between the categorical variables and compare PD-L1 scores with the mutation status.

Results

Most PTC (87%) and ATC (73%) cases were PD-L1 positive (TPS ≥1%), with significantly higher positivity rates than NG (20%). TPS >50% was seen in 60% ATC and 7% PTC cases. The median TPS and H-score of ATC were 56 (0-96.6) and 168 (0-275), respectively, and of PTC were 9.6 (4-16.8) and 17.8 (6.6-38.6), respectively. The scores were similar across the PTC subtypes. Only one case each of FTC and PDTC was PD-L1 positive. PD-L1 expression correlated significantly with BRAF^V600E, but not with RAS mutation.

Conclusions

ATC showed intense and diffuse PD-L1 staining. Although most PTCs were PD-L1 positive, the expression was weaker and patchy, irrespective of the histological subtype. Results of this pilot study indicate that ATC is most likely to respond to immunotherapy. PTC, FTC, and PDTC may be less amenable to immunotherapy. PD-L1 expression correlated significantly with BRAF^V600E, allowing for combined targeted therapy.

Prognostic of recurrence and survival in poorly differentiated thyroid cancer

The prognosis of poorly differentiated thyroid carcinomas (PDTC) defined by the Turin criteria is variable. The aim of this study on 51 PDTC patients was to determine clinical, histological and molecular prognostic factors associated with recurrence in patients with localized disease at initial treatment and with overall survival in patients with distant metastases. Of 40 patients for whom next-generation sequencing (NGS) by ThyroSeq v3 was able to be performed on historical samples, we identified high-risk molecular signature (TERT, TP53 mutations) in 24 (60%) cases, intermediate risk signature in 9 (22.5%) cases and low-risk signature in 7 (17.5%) cases. Potentially actionable mutations were identified in 10% of cases. After a median follow-up of 57.5 months, recurrence occurred in 11 (39%) of the 28 patients with localized disease. The American Thyroid Association (ATA) high risk of relapse, high mitotic count, high molecular risk signature and CD163 expression were associated with recurrence (P = 0.009, 0.01, 0.049, 0.03 respectively). After a median follow-up of 49.5 months, thyroid cancer-related death occurred in 53% of the patients with distant metastases. There was no significant prognostic factor associated with death in univariate analysis. However, none of the patients with intermediate ATA risk of recurrence and none of the patients with low-risk molecular signature died from the disease. In addition, high molecular-risk signature was associated with the presence of synchronous or metachronous distant metastasis (P = 0.007) and with poor overall survival (P = 0.01). In conclusion, ATA risk of relapse and high mitotic count was associated with higher rate of recurrence in localized PDTC. High molecular-risk signature was associated with the presence of distant metastasis and poor overall survival. Further studies are needed to determine if molecular testing adds to ATA risk stratification or response to therapy in predicting outcomes.

Core Needle Biopsy Can Early and Precisely Identify Large Thyroid Masses

Background

Large thyroid masses, particularly if rapidly growing, are often characterized by compression and infiltration of the vital structures of the neck. Therefore, an early and precise diagnosis, not only of malignancy but also of histotype, is mandatory to set up the right therapy. The aim of this study was to evaluate the diagnostic performance of fine needle aspiration cytology (FNAC) and core needle biopsy (CNB) in this setting.

Patients and Methods

We prospectively evaluated 95 patients with large and rapidly growing thyroid masses admitted to the University Hospital of Pisa between April 2014 and January 2020. All patients were submitted to FNAC and CNB in the same session. The ability of both procedures to diagnose the malignancy of the lesions, particularly the histotype, and to obtain sufficient material to perform molecular analysis was evaluated.

Results

FNAC obtained adequate tumor sample to reach a diagnosis in 76 of 95 (80%) patients, while a higher percentage was obtained with CNB (92/95, 96.8%). FNAC was able to identify the malignancy of the lesion in 74 of 95 (77.9%) cases, but only in 16 of 74 (21.6%) cases was it able to define the histotype. CNB was able to define the malignancy of the lesion in all but three cases (92/95, 96.8%), and in all specimens, the histotype was identified. Moreover, in all cases, the material extracted from CNB was optimal to perform molecular analysis. No surgery-related complications were experienced with both procedures.

Conclusions

CNB is a rapid and safe procedure with higher performance compared to FNAC in identifying the histotype of large and rapidly growing thyroid masses. Moreover, adequate material can be obtained to characterize the molecular profile for the treatment of potentially lethal cancers. In the era of precision medicine, CNB should be introduced in routine clinical practice as a key procedure for an early diagnosis and therapy of these diseases.

Poorly differentiated thyroid carcinoma: a clinician's perspective

Poorly differentiated thyroid carcinoma (PDTC) is a rare thyroid carcinoma originating from follicular epithelial cells. No explicit consensus can be achieved to date due to sparse clinical data, potentially compromising the outcomes of patients. In this comprehensive review from a clinician's perspective, the epidemiology and prognosis are described, diagnosis based on manifestations, pathology, and medical imaging are discussed, and both traditional and emerging therapeutics are addressed as well. Turin consensus remains the mainstay diagnostic criteria for PDTC, and individualized assessments are decisive for treatment option. The prognosis is optimal if complete resection is performed at early stage but dismal in nearly half of patients with locally advanced and/or distant metastatic diseases, in which adjuvant therapies such as 131I therapy, external beam radiation therapy, and chemotherapy should be incorporated. Emerging therapeutics including molecular targeted therapy, differentiation therapy, and immunotherapy deserve further investigations to improve the prognosis of PDTC patients with advanced disease.

Isolated adrenal metastases of papillary thyroid carcinoma

Not required for Clinical Vignette.

Postoperative radioiodine therapy impact on survival in poorly differentiated thyroid carcinoma: a population-based study

PURPOSE

The true impact of postoperative radioiodine therapy on survival has been controversial for patients with poorly differentiated thyroid carcinoma (PDTC). We aimed to determine the impact of postoperative radioiodine on survival in PDTC through a population-based study.

METHODS

Data on patients with PDTC were collected from the US SEER database (2004 to 2015). Patients were divided into the radioiodine group and nonradioiodine group. Survival comparison between groups was evaluated by Kaplan-Meier curves, log-rank test and multivariate Cox regression analysis. Akaike information criterion was used to select variables in the nomogram. The performance of the nomogram was assessed by discrimination (C-index) and calibration plots.

RESULTS

The radioiodine group had more aggressive features, such as advanced tumor node metastasis stage and radical surgery, compared to the nonradioiodine group. PDTC patients receiving radioiodine therapy had a significant survival advantage in terms of overall survival (OS) (P = 0.001) but not in terms of cancer-specific survival (P = 0.083). Multivariate analysis revealed radioiodine therapy was an independent favorable factor for OS in PDTC patients (hazard ratio = 0.57; 95% CI, 0.44-0.75, P < 0.001). Subgroup analysis identified patients' characteristics favoring radioiodine therapy. The nomogram (age, tumor size, extension, neck lymph nodes metastasis and radioiodine therapy) of OS for predicting 3-, 5- and 10-year OS probability showed good discrimination (C-index, 0.797) and calibration power.

CONCLUSION

Postoperative radioiodine therapy can prolong the long-term OS in patients with PDTC, and is an independent favorable prognostic factor for those patients. Further prospective studies are warranted.

Genomic Profiling of Aggressive Thyroid Cancer in Association With its Clinicopathological Characteristics

BACKGROUND/AIM

Poorly differentiated thyroid carcinoma (PDTC), anaplastic thyroid carcinoma (ATC), and advanced DTC have poor outcomes.

MATERIALS AND METHODS

We performed next-generation sequencing in nine selected aggressive thyroid cancers.

RESULTS

Among the nine patients, the driver gene mutations BRAF V600E (3/9) and NRAS Q61K (1/9) were detected. Other oncogenic mutations included ERBB2 (1/9) and CDK4 (1/9). Telomerase reverse transcriptase (TERT) promoter mutation was found in five cases. Among tumor suppressor genes, mutations in TP53 (3/9), ARID1A (1/9), APC (1/9), MEN1 (1/9), DICER1 (1/9), and MED12 (1/9) were identified. RET fusions were found in two cases, one with PTDC and the other with ATC. The ATC with RET fusion also harbored TP53 and TERT promoter mutations. None of the PDTC cases had BRAF or RAS gene alterations.

CONCLUSION

Since genetic alterations with therapeutic and prognostic implications were detected using next-generation sequencing, this technique is recommended to be performed for patients with aggressive thyroid cancer.

Development and validation of a nomogram model for cancer-specific survival of patients with poorly differentiated thyroid carcinoma: A SEER database analysis

BACKGROUND

This study aimed to establish and validate an accurate prognostic model, based on demographic and clinical parameters, for predicting the cancer-specific survival (CSS) of patients with poorly differentiated thyroid carcinoma (PDTC).

MATERIALS AND METHODS

Patients diagnosed with PDTC between 2004 to 2015 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Randomly split the data into training and validation sets. Kaplan-Meier analysis with the log-rank test was performed to compare the survival distribution among cases. Univariate and multivariate Cox proportional hazards regression analyses were used to identify independent prognostic factors, which were subsequently utilized to construct a nomogram for predicting the 5- and 10-year cancer-specific survival of patients with PDTC. The discriminative ability and calibration of the nomogram model were assessed using the concordance index and calibration plots, respectively. In addition, we performed a decision curve analysis to assess the clinical value of the nomogram. Simultaneously, we compared the predictive performance of the nomogram model against that of the American Joint Committee on Cancer (AJCC) T-, N-, M-stage.

RESULTS

A total of 970 eligible patients were randomly assigned to either a training cohort (n = 679) or a validation cohort (n = 291). The Kaplan-Meier analysis revealed that there were no significant differences in cumulative survival based on the race, radiation, and marital status of patients. The stepwise Cox regression model showed that the model was optimal when the following five variables were included: age, tumor size, T-, N-, and M-stage. A nomogram was developed as a graphical representation of the model and exhibited good calibration and discriminative ability in the study. Compared to the T-, N-, and M-stage, the C-index of nomogram (training group: 0.807, validation group: 0.802), the areas under the receiver operating characteristic curve of the training set (5-year AUC: 0.843, 10-year AUC:0.834) and the validation set (5-year AUC:0.878, 10-year AUC:0.811), and the calibration plots of this model all exhibited better performance. At last, compared with T-, N-, and M-stage, the decision curve analysis indicated that the nomogram had excellent clinical net benefit.

CONCLUSIONS

The nomogram developed by us can accurately predict the CSS of PDTC patients. It can help clinicians determine appropriate treatment strategies for poorly differentiated thyroid carcinoma patients.

Primary high-grade non-anaplastic thyroid carcinoma: a retrospective study of 364 cases

AIMS

We aimed to study the clinicopathological and molecular features of high-grade non-anaplastic thyroid carcinomas (HGTCs), a carcinoma with a prognosis intermediate between those of well-differentiated carcinoma and anaplastic carcinoma.

METHODS AND RESULTS

This study included 364 HGTC patients: 200 patients (54.9%) were diagnosed with poorly differentiated thyroid carcinoma (PDTC), based on the Turin consensus (HGTC-PDTC), and 164 were diagnosed with high-grade features that did not meet the Turin criteria (HGTC-nonPDTC). HGTCs are aggressive: the 3-year, 5-year, 10-year and 20-year disease-specific survival (DSS) rates were 89%, 76%, 60%, and 35%, respectively. Although DSS was similar between HGTC-PDTC and HGTC-nonPDTC patients, HGTC-PDTC was associated with higher rate of radioactive iodine avidity, a higher frequency of RAS mutations, a lower frequency of BRAF V600E mutations and a higher propensity for distant metastasis (DM) than HGTC-nonPDTC. Independent clinicopathological markers of worse outcome were: older age, male sex, extensive necrosis and lack of encapsulation for DSS; older age, male sex and vascular invasion for DM-free survival; and older age, necrosis, positive margins and lymph node metastasis for locoregional recurrence-free survival. The frequencies of BRAF, RAS, TERT, TP53 and PTEN alterations were 28%, 40%, 55%, 11%, and 10%, respectively. TP53, PTEN and TERT were independent molecular markers associated with an unfavourable outcome, independently of clinicopathological parameters. The coexistence of BRAF V600E and TERT promoter mutation increased the risk of DM.

CONCLUSIONS

The above data support the classification of HGTC as a single group with two distinct subtypes based on tumour differentiation: HGTC-PDTC and HGTC-nonPDTC.

Immune Checkpoint Protein Expression Defines the Prognosis of Advanced Thyroid Carcinoma

BACKGROUND

Patients with advanced thyroid carcinoma (TC), such as anaplastic thyroid carcinoma (ATC), poorly differentiated thyroid carcinoma (PDTC), and locally advanced papillary thyroid carcinoma (PTC), have poor prognoses and require novel treatments. Immune checkpoint (ICP) inhibitors have demonstrated encouraging and good results; nevertheless, their effect in advanced TCs remains largely unclear. Thus, we demonstrated ICP profiles and investigated their potential clinical significance.

METHODS

A total of 234 TC patients were involved, with 22 ATCs, 44 PDTCs, and 168 PTCs, including 58 advanced PTCs. Immunohistochemistry was performed to evaluate nine ICPs [programmed cell death ligand 1 (PDL1), Programmed cell death 1 (PD1), cytotoxic T lymphocyte-associated protein 4 (CTLA4), B and T lymphocyte attenuator (BTLA), T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT), lymphocyte activation gene 3 (LAG3), V-domain immunoglobulin suppressor of T-cell activation (VISTA), B7 homolog 3 (B7-H3), and T-cell immunoglobulin and mucin domain- 3 protein (TIM3)] expression via tissue microarrays (TMAs), and clinical correlations were analyzed simultaneously.

RESULTS

ATC had the highest positive rate of ICPs among the three pathological types, as well as relatively high ICP co-expression. ATC with high expression of PDL1 positivity had a poor prognosis. Shorter survival was associated with VISTA, B7H3, TIM3, and TIGIT expression in PDTC. The greater the co-expression of these four ICPs, the poorer the prognosis in PDTC patients. VISTA and B7H3 were the two most commonly expressed ICPs in advanced PTC, both of which were linked to a poor prognosis.

CONCLUSIONS

PDL1 is linked to the overall survival (OS) of ATC. A subset of PDTC is likely immunogenic with poor prognosis and co-expression of VISTA, B7H3, TIM3, and TIGIT. Furthermore, VISTA and B7H3 are prognostic biomarkers in advanced PTC. Single or combined blockade targeting these ICPs might be effective for advanced TCs in the future.

Prostate-Specific Membrane Antigen in Anaplastic and Poorly Differentiated Thyroid Cancer-A New Diagnostic and Therapeutic Target?

Several studies have demonstrated an expression of the prostate-specific membrane antigen (PSMA) in the cancer-related neovasculature of thyroid malignancies. Due to the poor prognosis and limited therapeutic options for patients with anaplastic (ATC) and poorly differentiated (PDTC) thyroid carcinoma, the aim of our study was to investigate the theranostic approach of PSMA expression in these patients. The PSMA uptake on Gallium-68 (⁶⁸Ga)-PSMA-positron emission tomography/computed tomography (PET/CT) and glucose uptake on F-18-Fluordeoxyglucose (¹⁸F-FDG)-PET/CTs were analysed in two ATC and six PDTC patients. The PSMA expression in corresponding patients' tissue samples was detected by immunohistochemistry. In addition, various tissue sections from 22 ATC and six PDTC patients were examined concerning PSMA expression. ⁶⁸Ga-PSMA-PET/CT showed heterogeneous PSMA expression among patients and lesions. Six of the eight analyzed patients (two ATC, four PDTC) showed increased glucose metabolism without increased PSMA uptake after PET/CT. In one patient (PDTC), ¹⁸F-FDG-PET/CT tracer uptake was positive and ⁶⁸Ga-PSMA-PET/CT showed heterogeneous results. Another patient (PDTC) evidenced only PSMA-positive lesions and received two cycles of Lutetium-177 (¹⁷⁷Lu)-PSMA therapy, which kept his disease stable for seven months. There was a correlation between immunohistochemical PSMA expression and uptake on ⁶⁸Ga-PMSA-PET/CT in three of the examined patients. Twenty-seven of the analyzed 39 ATC and 13 of the analyzed 22 PDTC tissue sections showed a strong PSMA expression. Considering the rarity of PDTC and ATC, which is the reason for the small patient population we studied, the findings of this study confirm the high diagnostic sensitivity and superiority of ¹⁸F-FDG-PET/CT in comparison to ⁶⁸Ga-PSMA-PET/CT in the diagnosis of ATC and PDTC. However, it can be suggested that ⁶⁸Ga-PMSA-PET/CT can be considered as a beneficial adjunct to the well-established ¹⁸F-FDG-PET/CT for a few individual selected patients with ATC and PDTC to detect lesions not discovered by ¹⁸F-FDG-PET/CT and to determine patients' eligibility for a radioligand therapy. Radiolabelled PSMA-ligands may, in the future, represent a theranostic approach with only minor side effects for a few individual selected patients with ATC and PDTC who need alternative treatment options in case of progression when established therapies are no longer effective. However, due to the small sample size of our collective, larger studies are needed to allow for a final evaluation on the significance of PSMA-targeted diagnostic and therapy for ATC and PDTC.

Poorly Differentiated Thyroid Carcinoma Coexisting with Graves' Disease Involving T3 Thyrotoxicosis due to Increased D1 and D2 Activities

Background: Poorly differentiated thyroid carcinoma is rare and patients are typically euthyroid. We report a novel rare case of poorly differentiated thyroid carcinoma with triiodothyronine (T3) thyrotoxicosis. Patient's Findings: A 77-year-old man presented to Kuma Hospital due to a neck tumor. A thyroid ultrasonography revealed a 220-mL mass in the right lobe. Laboratory data showed low serum thyrotropin (TSH), low free thyroxine (fT4), and high free T3 (fT3) levels. Anti-TSH receptor antibodies and thyroid-stimulating antibodies were positive. 131I scintigraphy showed diffuse uptake only in the left thyroid lobe. The patient underwent a total thyroidectomy and histological examination identified as poorly differentiated thyroid carcinoma. He was diagnosed with poorly differentiated thyroid carcinoma coexisting with Graves' disease. The tumor showed elevated type 1 iodothyronine deiodinases (D1) and type 2 iodothyronine deiodinases (D2) activities compared with that of the left thyroid lobe. Summary and Conclusions: Increased D1 and D2 activities in poorly differentiated carcinoma resulted in T3 toxicosis with a high serum fT3/fT4 ratio.

Impact of Epithelial-Mesenchymal Immunophenotype on Local Aggressiveness in Papillary Thyroid Carcinoma Invading the Airway

Primary thyroid tumours show different levels of aggressiveness, from indolent to rapidly growing infiltrating malignancies. The most effective therapeutic option is surgery when radical resection is feasible. Biomarkers of aggressiveness may help in scheduling extended resections such as airway infiltration, avoiding a non-radical approach. The aim of the study is to evaluate the prognostic role of E-cadherin, N-cadherin, Aryl hydrocarbon receptor (AhR), and CD147 in different biological behaviours. Fifty-five samples from three groups of thyroid carcinomas were stained: papillary thyroid carcinomas (PTCs) infiltrating the airway (PTC-A), papillary intra-thyroid carcinomas (PTC-B) and poorly differentiated or anaplastic thyroid carcinomas (PDTC/ATC). High expressions of N-cadherin and AhR were associated with higher locoregional tumour aggressiveness (p = 0.005 and p < 0.001 respectively); PDTC/ATC more frequently showed a high expression of CD147 (p = 0.011), and a trend of lower expression of E-cadherin was registered in more aggressive neoplasms. Moreover, high levels of AhR were found with recurrent/persistent diseases (p = 0.031), particularly when tumours showed a concomitant high N-cadherin expression (p = 0.043). The study suggests that knowing in advance onco-biological factors with a potential role to discriminate between different subsets of patients could help the decision-making process, providing a more solid therapeutic indication and an increased expectation for radical surgery.

Concomittant occurence of well-differentiated thyroid carcinoma metastasis and chronic lymphocytic leukemia in the same lymph node along with internal jugular vein thrombus: a case report

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is the most common adult leukemia. The coexistence of CLL and papillary thyroid carcinoma (PTC) is extremely rare. PTC sometimes shows microscopic vascular invasion but rarely cause a tumor thrombus in the internal jugular vein (IJV). It is also rare to find both differentiated and poorly differentiated types of thyroid cancer in the same metastatic location. We report a case of 63-year-old Turkish man with history of CLL who had CLL/SLL involvement and PTC metastasis in the same lymph node. Additionally, there was macroscopic metastasis to the IJV with poorly differentiated areas in the removed tumor thrombus. Patient was treated with total thyroidectomy, left radical neck dissection, resection of the left IJV segment that contained the tumor thrombus and radioactive iodine (RAI) therapy. Furthermore, metastatic lesions were found in the brain, lung and bone. Radiotherapy and chemotherapy were performed. However, our patient died approximately 12 months after thyroidectomy. To our knowledge, our present report is the first description with its current features.

Papillary Thyroid Carcinoma with High-Grade Features Versus Poorly Differentiated Thyroid Carcinoma: An Analysis of Clinicopathologic and Molecular Features and Outcome

Background: Similar to poorly differentiated thyroid carcinoma (PDTC), papillary thyroid carcinoma with high-grade features (PTC HGF) demonstrates increased mitotic activity and/or necrosis; however, PTC HGF is excluded from the World Health Organization (WHO) definition of PDTC based on maintained nuclear features of PTC. Methods: Consecutive tumors that met criteria for PTC HGF, defined as tumors with maintained nuclear features of PTC and mitoses numbering 5 or more per 10 contiguous high-power fields and/or tumor necrosis, and PDTC (defined as per the WHO criteria) were identified. Clinicopathologic characteristics, follow-up data, and targeted next-generation sequencing results were compared between groups. Results: There were 15 PTC HGF and 47 PDTC. PTC HGF was associated with a higher rate of pT4 disease (53% vs. 13%, p = 0.0027) and lymph node metastases (73% vs. 38%, p = 0.049). The disease-specific survival was worse for patients with PTC HGF compared with those with PDTC using Kaplan-Meier estimation (p < 0.001) and was worse in subgroup analysis evaluating patients with widely invasive PDTC (i.e., those with a similar rate of pT4 disease) and PTC HGF (p = 0.040). PTC HGF had a higher BRAF^V600E mutation rate (42% vs. 3%; p = 0.003), a trend toward more gene fusions (25% vs. 3%; p = 0.052), and a higher rate of relative gain of 1q (67% vs. 15%; p = 0.002) than PDTC. Conclusions: Our results demonstrate that PTC HGF are important to recognize based on their aggressive behavior. The molecular differences between PTC HGF and PDTC suggest that PTC HGF should be considered a distinct group from PDTC.

NTRK Fusion Genes in Thyroid Carcinomas: Clinicopathological Characteristics and Their Impacts on Prognosis

Chromosomal rearrangements of NTRK genes are oncogenic driver mutations in thyroid cancer (TC). This study aimed to identify NTRK fusion-positive thyroid tumors and to correlate them with clinical and pathological data and determine their prognostic significance. The cohort consisted of 989 different TC samples. Based on the detected mutation, samples were triaged, and those that were positive for a BRAF, HRAS, KRAS, NRAS, RET, RET/PTC or PAX8/PPARγ mutation were excluded from further analyses. NTRK fusion gene testing was performed in 259 cases, including 126 cases using next-generation sequencing. NTRK fusion genes were detected in 57 of 846 (6.7%) papillary thyroid carcinomas and in 2 of 10 (20.0%) poorly differentiated thyroid carcinomas. A total of eight types of NTRK fusions were found, including ETV6/NTRK3, EML4/NTRK3, RBPMS/NTRK3, SQSTM1/NTRK3, TPM3/NTRK1, IRF2BP2/NTRK1, SQSTM1/NTRK1 and TPR/NTRK1.NTRK fusion-positive carcinomas were associated with the follicular growth pattern, chronic lymphocytic thyroiditis and lymph node metastases. NTRK1-rearranged carcinomas showed a higher frequency of multifocality and aggressivity than NTRK3-rearranged carcinomas. Tumor size, presence of metastases, positivity for the NTRK3 or NTRK1 fusion gene and a late mutation event (TERT or TP53 mutation) were determined as factors affecting patient prognosis. NTRK fusion genes are valuable diagnostic and prognostic markers.

Predictive Factors for RAI-Refractory Disease and Short Overall Survival in PDTC

BACKGROUND

The clinical phenotype of poorly differentiated thyroid cancer (PDTC) can vary substantially. We aim to evaluate risk factors for radioiodine refractory (RAI-R) disease and reduced overall survival (OS).

METHODS

We retrospectively screened our institutional database for PDTC patients. For the assessment of RAI-R disease, we included patients who underwent dual imaging with ¹⁸F-FDG-PET and ¹²⁴I-PET/¹³¹I scintigraphy that met the internal standard of care. We tested primary size, extrathyroidal extension (ETE), and age >55 years as risk factors for RAI-R disease at initial diagnosis and during the disease course using uni- and multivariate analyses. We tested metabolic tumor volume (MTV), total lesion glycolysis (TLG) on ¹⁸F-FDG-PET, and the progression of stimulated thyroglobulin within 4-6 months of initial radioiodine therapy as prognostic markers for OS.

RESULTS

Size of primary >40 mm and ETE were significant predictors of RAI-R disease in the course of disease in univariate (81% vs. 27%, p = 0.001; 89% vs. 33%, p < 0.001) and multivariate analyses. Primary tumor size was an excellent predictor of RAI-R disease (AUC = 0.90). TLG/MTV > upper quartile and early thyroglobulin progression were significantly associated with shorter median OS (29.0 months vs. 56.9 months, p < 0.05; 57.8 months vs. not reached p < 0.005, respectively).

DISCUSSION

PDTC patients, especially those with additional risk factors, should be assessed for RAI-R disease at initial diagnosis and in the course of disease, allowing for early implementation of multimodal treatment. Primary tumor size >40 mm, ETE, and age >55 are significant risk factors for RAI-R disease. High MTV/TLG is a significant risk factor for premature death and can help identify patients requiring intervention.

Oncocytic Papillary Thyroid Carcinoma and Oncocytic Poorly Differentiated Thyroid Carcinoma: Clinical Features, Uptake, and Response to Radioactive Iodine Therapy, and Outcome

OBJECTIVE

The main objective of this study was to review the clinicopathologic characteristics and outcome of patients with oncocytic papillary thyroid carcinoma (PTC) and oncocytic poorly differentiated thyroid carcinoma (PDTC). The secondary objective was to evaluate the prevalence and outcomes of RAI use in this population.

METHODS

Patients with oncocytic PTC and PDTC who were treated at a quaternary cancer centre between 2002 and 2017 were retrospectively identified from an institutional database. All patients had an expert pathology review to ensure consistent reporting and definition. The cumulative incidence function was used to analyse locoregional failure (LRF) and distant metastasis (DM) rates. Univariable analysis (UVA) was used to assess clinical predictors of outcome.

RESULTS

In total, 263 patients were included (PTC [n=218], PDTC [n=45]) with a median follow up of 4.4 years (range: 0 = 26.7 years). Patients with oncocytic PTC had a 5/10-year incidence of LRF and DM, respectively, of 2.7%/5.6% and 3.4%/4.5%. On UVA, there was an increased risk of DM in PTC tumors with widely invasive growth (HR 17.1; p<0.001), extra-thyroidal extension (HR 24.95; p<0.001), angioinvasion (HR 32.58; p=0.002), focal dedifferentiation (HR 19.57, p<0.001), and focal hobnail cell change (HR 8.67, p=0.042). There was additionally an increased risk of DM seen in male PTC patients (HR 5.5, p=0.03).The use of RAI was more common in patients with larger tumors, angioinvasion, and widely invasive disease. RAI was also used in the management of DM and 43% of patients with oncocytic PTC had RAI-avid metastatic disease. Patients with oncocytic PDTC had a higher rate of 5/10-year incidence of LRF and DM (21.4%/45.4%; 11.4%/40.4%, respectively). Patients with extra-thyroidal extension had an increased risk of DM (HR 5.52, p=0.023) as did those with angioinvasion. Of the patients with oncocytic PDTC who received RAI for the treatment of DM, 40% had RAI-avid disease.

CONCLUSION

We present a large homogenous cohort of patients with oncocytic PTC and PDTC, with consistent pathologic reporting and definition. Patients with oncocytic PTC have excellent clinical outcomes and similar risk factors for recurrence as their non-oncocytic counterparts (angioinvasion, large tumor size, extra-thyroidal extension, and focal dedifferentiation). Compared with oncocytic PTCs, the adverse biology of oncocytic PDTCs is supported with increased frequency of DM and lower uptake of RAI.

Clinicopathological Characteristics and Prognosis of Poorly Differentiated Thyroid Carcinoma Diagnosed According to the Turin Criteria

OBJECTIVE

Poorly differentiated thyroid carcinoma (PDTC) is the primary cause of death in patients with nonanaplastic follicular cell-derived thyroid carcinoma. We purposed to identify the clinical and pathological characteristics of PDTC and their relationship with prognosis.

METHODS

A retrospective analysis was conducted on patients diagnosed with PDTC at our institution from 2010 to 2018. All of their histopathology slides were reviewed by 2 experienced pathologists based on the Turin criteria. Furthermore, information regarding clinical characteristics, pathological characteristics, treatment strategy, and follow-up events were collected. The Kaplan-Meier method was used for survival analysis, while the log-rank test was used to compare survival curves. Then, the Cox proportional hazards model was used to perform univariate and multivariate analyses.

RESULTS

Twenty-six patients with PDTC who met the Turin criteria were enrolled in this study. The median follow-up period of the included 26 patients was 76 months, while the 3- and 5-year survival rates were 40% and 18%, respectively. Notably, univariate analysis revealed that tumor size >4 cm (P = .038), extrathyroidal extension (ETE) (P = .020), distant metastases (P = .047), poorly differentiated areas >60% (P = .049), and Ki-67 labeling index >30% (P = .040) were associated with poor prognosis. On the other hand, multivariate analysis identified ETE (P = .007) and distant metastases (P = .031) as independent risk factors for poor prognosis.

CONCLUSION

PDTC is a rare carcinoma with high invasiveness and poor prognosis. Patients with ETE or distant metastases may have adverse outcomes.

The Oncocytic Variant of Poorly Differentiated Thyroid Carcinoma Shows a Specific Immune-Related Gene Expression Profile

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) is a rare, follicular cell-derived neoplasm with an unfavorable prognosis. The oncocytic variant of PDTC may be associated with even more adverse outcome than classical PDTC cases, but its specific molecular features are largely unknown. Our aim was to explore the immune-related gene expression profile of oncocytic and classical PDTC, in correlation with clinical and pathological characteristics (including programmed death ligand 1 [PD-L1] expression) and outcome, and in comparison with a control group of well-differentiated follicular carcinomas (WDFCs), including conventional follicular carcinomas (FTCs) and Hürthle cell carcinomas (HCCs).

METHODS

A retrospective series of 48 PDTCs and 24 WDFCs was analyzed by means of NanoString technology employing the nCounter PanCancer Immune Profiling panel. Gene expression data were validated using quantitative real-time polymerase chain reaction.

RESULTS

Oncocytic PDTCs showed a specific immune-related gene expression profile, with higher expression of LAIR2, CD274, DEFB1, IRAK1, CAMP, LCN2, LY96, and APOE, and lower expression of NOD1, as compared to conventional PDTCs. This molecular signature was associated with increased intratumoral lymphocytic infiltration, PD-L1 expression, and adverse outcome. Three of these genes, CD274, DEFB1, and IRAK1, as well as PD-L1 expression, were also the hallmarks of HCCs as compared to FTCs. By contrast, the panel of genes differentially regulated in PDTCs as compared to WDFCs was unrelated to the oncocytic phenotype.

CONCLUSIONS

Our results revealed a distinctive immune-related gene expression profile of oncocytic PDTC and confirmed a more aggressive outcome in this cancer subtype. These findings may provide guidance when exploring novel immunotherapeutic options for oncocytic PDTC patients.

Cytomorphologic features of thyroid disease in patients with DICER1 mutations: A report of cytology-histopathology correlation in 7 patients

BACKGROUND

Germline and somatic mutations of DICER1 have been identified in various types of neoplastic lesions, with germline DICER1 mutation being linked to autosomal dominant hereditary pleiotropic tumor syndrome (DICER1 syndrome). Patients with DICER1 syndrome are at increased risk of developing thyroid disease, including thyroid cancer. The goal of this study was to identify diagnostic cytologic features in thyroid fine-needle aspiration (FNA) samples from patients with DICER1 mutation.

METHODS

Cytology cases of thyroid FNA from 7 patients with DICER1 mutation were identified. Clinical, imaging, cytomorphologic, and molecular data were analyzed.

RESULTS

Cytologic preparations from reviewed cases showed thyroid lesions of follicular derivation with scant colloid, moderate cellularity, uniform follicular cells with round nuclei and inconspicuous nucleoli arranged in small crowded groups and microfollicles. Follicular neoplasm was diagnosed in 4 cases and follicular lesion of undetermined significance in 3 cases, based on the Bethesda System for Reporting Thyroid Cytopathology. Histopathological analysis of thyroid tissue confirmed neoplastic process in 6 out of 7 cases: follicular carcinoma (FC, 3 cases), papillary thyroid carcinoma (2 cases), poorly differentiated thyroid carcinoma (PDTC, 1 case). Genetic studies identified 3 different somatic variants of DICER1 gene, including transcript consequence c.5428G>T, which was detected in FC and PDTC (and has been described previously in multinodular goiter).

CONCLUSION

DICER1 mutation in all analyzed patients was identified as a result of thyroid FNA evaluation, emphasizing the critical role of FNA in the screening of patients with thyroid nodules, proper diagnosis of thyroid disease, and monitoring of patients with DICER1 mutation.

Poorly differentiated thyroid carcinoma of childhood and adolescence: a distinct entity characterized by DICER1 mutations

Poorly differentiated thyroid carcinomas (PDTC) in young individuals are rare and their clinical and histopathologic features, genetic mechanisms, and outcomes remain largely unknown. Here, we report a detailed characterization of a series of six PDTC in patients ≤21 years old defined by Turin diagnostic criteria studied for mutations and gene fusions characteristic of thyroid cancer using targeted next-generation sequencing (NGS) and whole-exome sequencing (WES). All tumors had solid, insular, or trabecular growth pattern and high mitotic rate, and five out of six tumors showed tumor necrosis. Targeted NGS assay identified somatic mutations in the DICER1 gene in five of six (83%) tumors, all of which were "hotspot" mutations encoding the metal-ion binding sites of the RNase IIIb domain of DICER1. WES was performed in five cases which confirmed all hotspot mutations and detected two tumors with additional inactivating DICER1 alterations. Of these two, one was a germline pathogenic DICER1 variant and the other had loss of heterozygosity for DICER1. No other mutations or gene fusions characteristic of adult well-differentiated thyroid cancer and PDTC (BRAF, RAS, TERT, RET/PTC, and other) were detected. On follow-up, available for five patients, three patients died of disease 8-24 months after diagnosis, whereas two were alive with no disease. The results of our study demonstrate that childhood- and adolescent-onset PDTC are genetically distinct from adult-onset PDTC in that they are strongly associated with DICER1 mutations and may herald DICER1 syndrome in a minority. As such, all young persons with PDTC may benefit from genetic counseling. Furthermore, their clinically aggressive behavior contrasts sharply with the indolent nature of the great majority of thyroid tumors with DICER1 mutations reported to date.

Mutational profiling of poorly differentiated and anaplastic thyroid carcinoma by the use of targeted next-generation sequencing

AIMS

To characterise the mutational profiles of poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC) and to identify markers with potential diagnostic, prognostic and therapeutic significance.

METHODS AND RESULTS

Targeted next-generation sequencing with a panel of 18 thyroid carcinoma-related genes was performed on tissue samples from 41 PDTC and 25 ATC patients. Genetic alterations and their correlations with clinicopathological factors, including survival outcomes, were also analysed. Our results showed that ATC had significantly higher mutation rates of BRAF, TP53, TERT and PIK3CA than PDTC (P = 0.005, P = 0.007, P = 0.005, and P = 0.033, respectively). Nine (69%) ATC cases with papillary thyroid carcinoma (PTC) components harboured BRAF mutations, all of which coexisted with a late mutation event (TP53, TERT, or PIK3CA). Nine cases with oncogenic fusion (six RET cases, one NTRK1 case, one ALK case, and one PPARG case) were identified in 41 PDTCs, whereas only one case with oncogenic fusion (NTRK1) was found among 25 ATCs. Moreover, all six cases of RET fusion were found in PDTC with PTC components, accounting for 33%. In PDTC/ATC patients, concurrent TERT and PIK3CA mutations were associated with poor overall survival after adjustment for TNM stage (P = 0.001).

CONCLUSIONS

ATC with PTC components is typically characterised by a BRAF mutation with a late mutation event, whereas PDTC with PTC components is more closely correlated with RET fusion. TERT and concurrent PIK3CA mutations predict worse overall survival in PDTC/ATC patients.

Prognostic Significance of Extent of Invasion in Poorly Differentiated Thyroid Carcinoma

Background: The 2017 World Health Organization (WHO) Classification of Tumors of Endocrine Organs defines poorly differentiated thyroid carcinoma (PDTC) as a tumor with conventional criteria of malignancy (capsular penetration or vascular invasion) with solid, insular, or trabecular growth, a lack of nuclear features of papillary thyroid carcinoma, and increased mitotic activity, tumor necrosis, or convoluted nuclei. The extent of invasion has been shown to be prognostic in follicular thyroid carcinoma and Hürthle cell carcinoma. Our aim was to evaluate how extent of invasion impacts clinical outcome for PDTC. Methods: We retrospectively identified 47 consecutively diagnosed cases of PDTC that were resected between 2005 and 2018. All cases were reviewed to confirm that the tumors met the 2017 Endocrine WHO criteria of PDTC. In addition, tumors were categorized as follows: encapsulated with capsular penetration only, encapsulated with focal vascular invasion (fewer than four foci), encapsulated with extensive vascular invasion (four or more foci), or widely invasive. Histopathologic characteristics and clinical outcome data were recorded. Results: A total of 47 cases of PDTC, including 15 oncocytic tumors, were identified from 28 (60%) women and 19 (40%) men (mean age of 57 years at diagnosis). The mean tumor size was 4.3 cm. Mitoses numbered 8 per 10 high-power fields (HPF) on average (range: 1-34), and necrosis was present in 21 (45%) cases. Eight (17%) cases were encapsulated with capsular penetration only, 5 (11%) were encapsulated with focal vascular invasion, 18 (38%) were encapsulated with extensive vascular invasion, and 16 (34%) were widely invasive. Of the 42 (89%) patients with follow-up data, 7 (17%) died of disease (with a mean survival time of 6.4 years), 11 (26%) have distant metastatic disease, and 24 (57%) have no evidence of disease (mean follow-up 5.6 years). Eight (19%) patients presented with M1 disease at diagnosis. The 5-year disease-free survival (DFS) for patients with M0 disease at diagnosis was 100% for patients with tumors with capsular invasion only or focal vascular invasion (n = 7), 73% for patients with encapsulated tumors with extensive vascular invasion (n = 11), and 17% for patients with widely invasive PDTCs (n = 6). DFS estimates by Kaplan-Meier analysis were significantly different between these groups (p = 0.0016). Conclusions: Extent of invasion appears to be an important parameter that affects clinical outcome for patients with PDTC. In our cohort, patients with encapsulated PDTC with capsular invasion only or focal vascular invasion had an excellent outcome.

Therapeutic Delivery of miR-143 Targeting Tumor Metabolism in Poorly Differentiated Thyroid Cancer Xenografts and Efficacy Evaluation Using 18F-FDG MicroPET-CT

Poorly differentiated thyroid carcinoma cells tend to be more aggressive and show enhanced glucose uptake which could be exploited for anti-cancer strategy. Previously, we identified hexokinase 2 (HK2) as a direct target of miR-143. In our current study, the effects of miR-143 on glucose metabolism and tumor biological behavior were investigated in FTC-133 cells which is a poorly differentiated thyroid carcinoma (PDTC). Additionally, tumor-bearing mice xenografts of PDTC were constructed, with encapsulated miR-143 agomir being administered intravenously. 18F-FDG microPET-CT scanning was used for the evaluation of therapeutic efficacy. The tumor-restrained effect of miR-143 was demonstrated in PDTC. Furthermore, microPET/CT imaging exhibited a reduction of 18F-FDG uptake in tumors, corresponding to the downregulated expression of HK2 in tissues. In summary, our results suggest that miR-143 can be an alternative treatment for PDTC and the specific assessment of therapeutic response to miR-143 can be achieved by 18F-FDG microPET/CT in advanced thyroid carcinoma xenografts.

Effect of Buparlisib, a Pan-Class I PI3K Inhibitor, in Refractory Follicular and Poorly Differentiated Thyroid Cancer

BACKGROUND

Dysregulation of the phosphatidylinositol 3-kinase (PI3K) pathway is frequent in advanced follicular (FTC) and poorly differentiated thyroid (PDTC) carcinomas and has been implicated in oncogenesis and tumor progression. This study investigated the efficacy and safety of buparlisib, a pan-PI3K inhibitor in radioiodine refractory FTC and PDTC.

METHODS

The primary endpoint of this open-label, multicenter, phase 2 pilot study was progression-free survival (PFS) at 6 months. The sample size was determined considering that a PFS ≤50% at 6 months would denote an absence of benefits (null hypothesis). Secondary endpoints were objective response rate, PFS at 12 months, overall survival at 6 and 12 months, and safety based on the frequency and severity of adverse events (AEs).

RESULTS

Forty-three patients (19M/24 F; median age: 67 years) with metastatic, radioiodine refractory, progressive disease received buparlisib, 100 mg, daily. Histology was PDTC in 25 (58%), FTC in 17 (40%), and Hürthle cell carcinoma in 1 (2%). RAS mutation was found in 44% (12/27) and activation of the PI3K pathway in 35% (8/23) of tested tumors. The probability of PFS was 41.7% [95% confidence interval (CI) 7.7-55.5] at 6 months and 20.9% [CI 0-35.7] at 12 months, lower than the 50% expected PFS. At 6 months, 25.6% patients had stable disease, 48.8% were progressive and 25.6% had stopped treatment due to AE. The response to therapy was not influenced by age, sex, histology, or genetic alterations. The overall survivals at 6 and 12 months were 85.9% [CI 76-97] and 78.7 % [CI 67-92], respectively. The mean tumor growth rate decreased from 3.78 mm/month [CI 2.61-4.95] before treatment to 0.8 mm/month [CI -0.2-1.88] during treatment (p < 0.02). Severe grade 3-4 AEs occurred in 27 patients (63%), including hepatitis (25%), hyperglycemia (21%), mood disorders (12%), and skin toxicity (12%), with favorable outcome after temporary or permanent treatment discontinuation or dose reduction.

CONCLUSIONS

Buparlisib did not result in significant efficacy in advanced FTC and PDTC. However, the decrease in tumor growth rate may suggest incomplete inhibition of oncogenic pathways and/or escape mechanisms. This should lead to evaluate combined therapy associating inhibitors of both the PI3K and mitogen-activated protein kinase pathways.

Thyroglobulin "Nonsecretor" Metastatic Poorly Differentiated Thyroid Carcinoma with Noniodine Concentrating Disease and Aggressive Clinical Course: A Clinical Case Series

Poorly differentiated thyroid carcinomas (PDTC) are a subgroup of thyroid cancers with aggressive behavior and worse prognosis compared to the well DTC. Limited diagnostic tools and therapeutic options exist for such cases, and the appropriate management algorithm continues to evolve in this subgroup. They pose difficulty in clinical management due to their behavioral heterogeneity and increased occurrence of aggressive clinical behavior underlining the need for management individualization. In the present communication, a case series of three clinically challenging cases of PDTC (with low serum thyroglobulin (Tg) and iodine nonavidity) are presented with a discourse on their management intrigues, unresolved issues and the requirement of a distinctive management protocol. A small fraction of PDTCs may show low serum Tg values, with the questionable significance of its role for the assessment and monitoring of disease burden in this group of patients. Given uncommon occurrence, limited and variable literature data, management guidelines for “nonsecretor” PDTC needs to be more clearly defined based on scientific evidence. The present clinical case series of PDTC with low serum thyroglobulin in the context of noniodine concentrating metastatic disease and aggressive clinical course (”nonsecretor” status) was noteworthy from this viewpoint.

Identification of CHEK1, SLC26A4, c-KIT, TPO and TG as new biomarkers for human follicular thyroid carcinoma

The search for preoperative biomarkers for thyroid malignancies, in particular for follicular thyroid carcinoma (FTC) diagnostics, is of utmost clinical importance. We thus aimed at screening for potential biomarker candidates for FTC. To evaluate dynamic alterations in molecular patterns as a function of thyroid malignancy progression, a comparative analysis was conducted in clinically distinct subgroups of FTC and poorly differentiated thyroid carcinoma (PDTC) nodules. NanoString analysis of FFPE samples was performed in 22 follicular adenomas, 56 FTC and 25 PDTC nodules, including oncocytic and non-oncocytic subgroups. The expression levels of CHEK1, c-KIT, SLC26A4, TG and TPO were significantly altered in all types of thyroid carcinomas. Based on collective changes of these biomarkers which correlating among each other, a predictive score has been established, allowing for discrimination between benign and FTC samples with high sensitivity and specificity. Additional transcripts related to thyroid function, cell cycle, circadian clock, and apoptosis regulation were altered in the more aggressive oncocytic subgroups only, with expression levels correlating with disease progression. Distinct molecular patterns were observed for oncocytic and non-oncocytic FTCs and PDTCs. A predictive score correlation coefficient based on collective alterations of identified here biomarkers might help to improve the preoperative diagnosis of FTC nodules.

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET-PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular-patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non-invasive follicular thyroid neoplasm with papillary-like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen-activated protein kinase and phosphoinositide 3-kinase-PTEN-AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance.

Long-term efficacy and safety of fourth-line multikinase inhibitor treatment with lenvatinib in a young papillary thyroid carcinoma patient

Lenvatinib, a multikinase inhibitor, is approved for the treatment of patients with radioiodine-refractory metastatic thyroid cancer on the basis of a Phase III, prospective, double-blind, randomized, placebo-controlled trial that showed longer progression-free survival in the drug-treated arm. Here, we report the case of a young papillary thyroid cancer patient, pretreated with three other kinase inhibitors, who achieved a long-term clinical benefit from lenvatinib in the fourth-line setting.

A review of the recent literature

Poorly differentiated thyroid carcinoma (PDTC) is a follicular cell-derived tumour that was recognised as a distinct entity by the World Health Organisation in 2004. The natural history and pathological features of PDTC are reported to be intermediate between those of well-differentiated and undifferentiated (anaplastic) thyroid carcinomas. Preoperative identification of PDTC could facilitate better initial patient management in many cases, namely more extensive surgery, without any delay. However, according to some experts, a diagnosis of PDTC can only be rendered on histologic specimens based on criteria recommended in the Turin proposal. Although high-grade features (namely necrosis and mitoses) can be recognised in FNA material, other cytomorphological features have limited value for the preoperative diagnosis of PDTC and specific features for a definitive diagnosis of PDTC have not yet been clearly defined. Here, we review the current status and future prospects for cytological recognition of PDTC; we emphasise the features that should raise suspicion of this rare condition in FNA cytology and provide an update on molecular features and management of PDTC. Despite proposed histological criteria for the diagnosis of PDTC, its recognition on routine thyroid cytology presents a notable challenge. Current and future advances in molecular testing could contribute to the cytological diagnosis of PDTC.

Oncocytic variant of poorly differentiated thyroid carcinoma: "Is diagnosis possible by fine-needle aspiration?"

Poorly differentiated thyroid carcinoma (PDTC) is a very rare entity, and the diagnosis can be made on histopathology specimens. However, recognition of characteristic features of PDTC is significant on fine-needle aspirations (FNAs) to differentiate this entity from well-differentiated and anaplastic thyroid carcinomas. Here, we present an FNA case concordant with “oncocytic variant of PDTC” and discuss whether definitive diagnosis can be given on FNAs to assess the prognosis in clinically inoperable patients.

Description and Comparison of the Sonographic Characteristics of Poorly Differentiated Thyroid Carcinoma and Anaplastic Thyroid Carcinoma

OBJECTIVES

Although poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma account for a substantial portion of the morbidity and mortality associated with thyroid cancer, a chance of a cure exists with aggressive treatment, especially in patients with poorly differentiated thyroid carcinoma. The goal of this study was to evaluate the sonographic characteristics of poorly differentiated thyroid carcinoma and to compare the sonographic findings of poorly differentiated and anaplastic thyroid carcinomas.

METHODS

The study included 29 patients with 30 poorly differentiated thyroid carcinomas and 26 patients with 26 anaplastic thyroid carcinomas. Two radiologists retrospectively reviewed sonographic findings. Clinical and sonographic findings were compared between poorly differentiated and anaplastic thyroid carcinomas by univariate and multivariate analyses.

RESULTS

In the group of patients with poorly differentiated thyroid carcinoma, the mean age was 53.7 years (range, 14-73 years), and the mean tumor size was 3.6 cm (range, 0.6-10.0 cm). The common sonographic findings of poorly differentiated thyroid carcinoma were heterogeneous echogenicity (93.3%), solitary nodules (80.0%), a circumscribed margin (63.3%), an oval-to-round shape (63.3%), and hypoechogenicity (60.0%). A circumscribed margin (P = .003) and an oval-to-round shape (P = .015) were significantly more frequent in poorly differentiated thyroid carcinoma than in anaplastic thyroid carcinoma. In the multivariate analysis, only the circumscribed margin on sonography was an independent predicting factor for poorly differentiated thyroid carcinoma (odds ratio, 4.642).

CONCLUSIONS

Both poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma commonly present as a relatively large malignant mass on sonography; however, poorly differentiated thyroid carcinoma showed a significantly higher incidence of a circumscribed margin and an oval-to-round shape than anaplastic thyroid carcinoma. Knowledge of sonographic characteristics will be useful for differentiation of poorly differentiated and anaplastic thyroid carcinomas.

Fine needle aspiration cytology features of poorly differentiated thyroid carcinoma

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) is an uncommon thyroid malignancy with biological behaviour intermediate between well-differentiated and undifferentiated thyroid carcinoma. The cytological diagnosis of PDTC is often difficult as a result of a lack of well-established cytomorphological features and a considerable degree of morphological overlap with other commoner thyroid neoplasms.

OBJECTIVE

To review the cytomorphological features of PDTC with the aim of highlighting salient diagnostic morphological features and differential diagnostic problems.

METHODS

Seven cases of histologically proven PDTC with available aspiration cytology smears were reviewed for the presence of distinguishing cytomorphological features.

RESULTS

The architectural arrangement of tumour cells was the most important diagnostic parameter. Cellular nests, three-dimensional clusters dyscohesive aggregates and singly dispersed cells in the background were present in all cases. A unique 'garlanded appearance', owing to the peripheral orientation of nuclei within the tumour cell clusters, was noted (71.4%) along with the presence of basement membrane-like material (71.4%). Transgressing vessels (85.7%) and endothelial wrapping of cell clusters (71.4%) were also noted. Interestingly, most cases lacked necrosis and mitotic activity that are included in the histological diagnostic criteria for PDTC.

CONCLUSION

Although PDTC has considerable cytomorphological overlap with well-differentiated thyroid tumours, this present study highlights certain cytomorphological features that may suggest the correct pre-operative diagnosis, important for the appropriate management.

Neoadjuvant chemotherapy in 13 patients with locally advanced poorly differentiated thyroid carcinoma based on Turin proposal - a single institution experience

BACKGROUND

There is a paradigm that chemotherapy is ineffective in thyroid carcinoma. The aim of our study was to find out whether neoadjuvant chemotherapy before thyroid surgery had an effect on the size of primary tumour in patients with poorly differentiated thyroid carcinoma (PDTC) based on Turin proposal.

PATIENTS AND METHODS

Altogether, 13 patients (8 women, 5 men; median age 61 years) with PDTC based on Turin proposal were treated with neoadjuvant chemotherapy between 1986 and 2005. Tumour diameter was from 4.5 to 18 cm (median 9 cm). Regional and distant metastases were detected in 6 and 9 patients, respectively. Eight patients had pT4 tumour.

RESULTS

Altogether, 29 (range 1-5) cycles of chemotherapy were given. Tumour diameter decreased in all the patients and by more than 30% in 5 patients (= 38%). Two of these five patients had also preoperative external beam irradiation (EBRT). Total thyroidectomy, lobectomy and neck dissection were performed in 10, 3 and 5 cases, respectively. R0 and R1 resection was done in 5 and 8 cases, respectively. Eight patients had postoperative EBRT of the neck and upper mediastinum. The 5-year and 10-year cause-specific survival rates of patients were 66% and 20%, respectively.

CONCLUSIONS

After neoadjuvant chemotherapy a partial tumour regression was observed in 38% of patients with PDTC based on Turin proposal.

Poorly differentiated thyroid carcinoma: a retrospective clinicopathological study

Poorly differentiated thyroid carcinoma (PDTC) is an independent thyroid cancer histotype. In spite of its scarcity, it represents the main cause of death from non-anaplastic follicular cell-derived thyroid cancer. However, given the newness of this entity, few data are available on its clinical behaviour and no explicit consensus sets its treatment. To report the experience of a tertiary medical centre in morocco with PDTC over a period of 7 years. Retrospective study selecting all patients treated for thyroid carcinoma in Nuclear Medicine Department of a tertiary medical centre in Casablanca over seven years period. Patient's files were reviewed for background data, clinico-pathological characteristics, treatment and outcome. Seven patients were included in the study. Patient's average age was 60 years old (30-81) including six women and one man. All patients underwent a total thyroidectomy completed by cervical lymph node dissection in 57% of cases. Mean primary tumour size was 4cm (1-9cm). Patients were classified pT3 in 70% of cases, pT1 and pT2 in 15% each. Vascular invasion was found in 85% of cases. Pathological subtypes found were "insular carcinoma" in 85% of cases. Radioiodine therapy (RIT) was indicated in all cases. Follow-up period ranged between 10 months and 6 years. It showed a complete remission in 57% of cases, persistent disease in 28% of cases and a progressive disease in 15% of cases with a local recurrence. To date, the survival rate is 85%. PDTC is an aggressive thyroid cancer histotype. Treatment remains surgical followed by RIT if the tumour is radioavid. Multimodality therapy is indicated depending on the case and close monitoring is always indicated given the high risk of relapse.

Search for new genetic biomarkers in poorly differentiated and anaplastic thyroid carcinomas using next generation sequencing

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC) are very rare tumors with extremely aggressive behavior. Their comprehensive genetic background is still unclear. Some of the main genetic changes of differentiated thyroid carcinomas, such as mutations in BRAF and RAS genes, as well as changes in CTNNB1, PIK3CA, TP53, AXIN1, PTEN or APC genes leading to the dedifferentiation of the tumors, are described.

MATERIALS AND METHODS

DNAs from fresh frozen thyroid tissues of 3 PDTCs and 5 ATCs were extracted. The next-generation sequencing (NGS) approach was used to target 94 genes involved in cancer. The samples were prepared using a TruSight Cancer panel and sequenced with a MiSeq sequencer. Analysis of variants was performed by the MiSeq Reporter and NextGENe software and stringent criteria for prioritization of the variants were used in the Illumina VariantStudio software.

RESULTS

Using NGS, we identified 26 genetic changes in 18 genes, novel variants included.

CONCLUSION

NGS is a useful tool for searching for new variants and genes involved in PDTC and ATC. It seems that each of these rare tumor types has its own specific genetic background. These data could be helpful for recognizing new genetic markers and targets for future personalized therapy.

Cribriform-morular variant of papillary thyroid carcinoma displaying poorly differentiated features

Cribriform-morular variant of papillary thyroid carcinoma (CMVPTC) usually occurs in the setting of familial adenomatous polyposis (FAP) although it can rarely arise sporadically. Poorly differentiated thyroid carcinoma (PDTC) is a follicular cell-derived neoplasm with more aggressive behavior than well-differentiated carcinomas such as CMVPTC. We report the case of a 35-year-old woman without FAP history who presented a left neck mass and complained of back pain. Imagiological examinations revealed a nodule in the left lobe of thyroid and multiple nodular lesions in the bone and lungs suggestive of metastases. The patient was submitted to total thyroidectomy and radioactive iodine. The tumor was composed of CMVPTC and PDTC components that shared the same somatic APC gene mutation (p.Cys520Tyr_fsX534). Besides this mutation, no CTNNB1, BRAF, N-RAS, and H-RAS gene mutations were detected in any of the 2 components. To the best of our knowledge, this is the first report of a sporadic CMVPTC with transformation into PDTC. Although the majority of CMVPTCs carry an indolent clinical outcome, the coexistence of poorly differentiated areas may justify the aggressiveness of the CMVPTC reported here.