Cribriform-morular variant of papillary thyroid carcinoma: a distinctive type of thyroid cancer

The Long Journey towards Personalized Targeted Therapy in Poorly Differentiated Thyroid Carcinoma (PDTC): A Case Report and Systematic Review

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) has an intermediate prognosis between indolent well-differentiated thyroid carcinoma (TC) and anaplastic carcinoma. Herein, we present a case report with a PDTC component, along with a systematic review of the literature.

CASE REPORT

We report a case of a 45-year-old man diagnosed with a PDTC component, along with hobnail and tall-cell variant features positive for BRAFV600E mutation, after a total thyroidectomy and neck dissection. Radioactive iodine (RAI)-131 therapy was applied, but an early recurrence led to complementary surgeries. The anti-Tg rise, the presence of new lymph nodes, and the negative whole-bodyradioiodine scan were suggestive of a radioiodine-resistant tumor. Lenvatinib, sorafenib, dabrafenib/trametinib, cabozantinib and radiotherapy were all administered, controlling the tumor for a period of time before the patient ultimately died post-COVID infection. Systematic Review: We searched PubMed, Scopus, and WebofScience to identify studies reporting clinicopathological characteristics, molecular marker expression, and management of non-anaplastic TC with any proportion of PDTC in adult patients. Of the 2007 records retrieved, 82were included in our review (PROSPERO-ID545847).

CONCLUSIONS

Our case, together with the systematic review, imply that a combination of molecular-targetedtreatments may be safe and effective in patients with RAI-resistantBRAF-mutated advanced PDTC when surgery has failed to control tumor progression.

Molecular Alterations in Pediatric Solid Tumors

Pediatric tumors can be divided into hematologic malignancies, central nervous system tumors, and extracranial solid tumors of bone, soft tissue, or other organ systems. Molecular alterations that impact diagnosis, prognosis, treatment, and familial cancer risk have been described in many pediatric solid tumors. In addition to providing a concise summary of clinically relevant molecular alterations in extracranial pediatric solid tumors, this review discusses conventional and next-generation sequencing-based molecular techniques, relevant tumor predisposition syndromes, and the increasing integration of molecular data into the practice of diagnostic pathology for children with solid tumors.

Difficulties of Preoperative Diagnosis of Cribriform Morular Thyroid Carcinoma

Background

Cribriform morular thyroid carcinoma has been recently renamed in the 2022 WHO classification as a thyroid tumor of uncertain histogenesis. The epidemiologic, pathological, and pathophysiological characteristics distinguish it from papillary thyroid carcinoma (PTC). Preoperative genetic testing plays a role in facilitating the differential diagnosis.

Methods

This report presents a confirmed case of cribriform morular thyroid carcinoma. Initially, fine-needle aspiration cytology suggested a diagnosis of PTC. However, a genetic analysis did not reveal the typical mutations associated with follicular-cell-derived neoplasms.

Results

A 31-year-old woman was found to have a thyroid nodule at the left lobe measuring 11.8 × 10.2 × 12.4 mm. Ultrasonography indicated a hypoechoic, solid nodule with regular margins. Cytology revealed a papillary structure of tall cells, leading to a PTC diagnosis. Nevertheless, the genetic analysis failed to detect mutations such as BRAF V600E, NRAS Q61R, NRAS Q61K, HRAS Q61R, or HRAS Q61K mutation or the fusion of CCDC6-RET, NCOA4-RET, PAX8-PPARG, ETV6-NTRK3, TPM3-NTRK1, IRF2BP2-NTRK1, or SQSTM1-NTRK1 in the aspirated follicular cells. The patient subsequently underwent total thyroidectomy with central lymph node dissection. Pathological examination revealed a cribriform pattern of spindle-shaped cells with morular areas. Immunohistochemical staining showed positive results for β-catenin and TTF-1, except in the morular regions, and negative results for PAX8, thyroglobulin, and BRAF (clone VE1). The diagnosis was confirmed to be cribriform morular thyroid carcinoma.

Conclusion

Significant cytological similarity exists between PTC and cribriform morular thyroid carcinoma. Preoperative genetic analysis is important to differentiate these two diseases. Cribriform morular thyroid carcinoma can be differentiated from common follicular-cell-derived tumors by the absence of typical mutations; the presence of nuclear and cytoplasmic expressions of β-catenin; the presence of TTF-1, except in morular areas; and the absence of thyroglobulin.

A Rare Case of Persistent Multifocal Cribriform-Morular Thyroid Carcinoma

Background/Objective

Cribriform-morular thyroid carcinoma (CMTC) was considered a variant of papillary thyroid carcinoma (PTC) but is a separate entity in the 2022 World Health Organization classification. CMTC has an association with familial adenomatous polyposis (FAP). Our objective is to report a case of CMTC who was subsequently diagnosed with FAP, to highlight these associated entities and implications for management.

Case Report

A 15-year-old female with a history of iron-deficiency anemia and alpha-gal syndrome presented with several years of goiter and dysphagia. She also noted unintentional weight loss, abdominal pain, melena and hematochezia, and symptomatic anemia. Physical examination was significant for multiple thyroid nodules. Laboratory results revealed normal thyroid function and iron deficiency. Multiple nodules were visualized on thyroid ultrasound, and fine needle aspiration biopsy was consistent with PTC. Total thyroidectomy was performed with a revised diagnosis of multifocal CMTC, with administration of adjuvant radioactive iodine due to persistent disease. Genetic testing confirmed FAP and she was referred for upper endoscopy, colonoscopy, and an evaluation for colectomy.

Discussion

There are no best practice guidelines for management of CMTC. Management of CMTC is guided by FAP status; sporadic cases can be managed with hemithyroidectomy, while FAP-associated cases are better managed with total thyroidectomy. Recurrence is usually managed with surgical resection. The decision to treat with adjuvant radioactive iodine is often extrapolated from management of classic PTC.

Conclusion

Thyroid carcinoma in the setting of extensive family history of colorectal carcinoma should arouse suspicion for CMTC. Patients with CMTC should receive a referral for colonoscopy and genetic testing for FAP.

Thyroid Metastasis to the Colon

Approximately 1% of colorectal cancers can be attributed to metastatic neoplasms originating from other primary sources typically the lung, ovary, breast, prostate, kidney, or skin. Metastasis to the colon from the thyroid however is exceedingly rare. We present a 76-year-old man with a history of papillary thyroid carcinoma WHO presented with colon polyps consistent with carcinoma from his papillary thyroid carcinoma. The findings in this report suggest prompt colorectal cancer screening after thyroid cancer diagnosis and regular screening thereafter.

Cribriform Morular Thyroid Carcinoma - Ultimobranchial Pouch-Related? Deep Molecular Insights of a Unique Case

A 44-year-old female patient with a familial adenomatous polyposis (FAP) was diagnosed with a cribriform morular thyroid carcinoma (CMTC). We observed within the very necrotic tumor a small but distinct poorly differentiated carcinomatous component. As expected, next generation sequencing of both components revealed a homozygous APC mutation and in addition, a TERT promoter mutation. A TP53 mutation was found exclusively in the CMTC part, while the poorly differentiated component showed a clonal evolution, harboring an activating PIK3CA mutation and copy number gains of BRCA2, FGF23, FGFR1, and PIK3CB-alterations which are typically seen in squamous cell carcinoma. The mutational burden in both components was low, and there was no evidence for microsatellite instability. No mutations involving the mitogen-activated protein kinase (MAPK) pathway, typically seen in papillary thyroid carcinomas, were detected. Immunohistochemically, all tumor parts were negative for thyroglobulin, providing further evidence that this entity does not belong to the follicular epithelial cell-derived thyroid carcinoma group. CD5 was negative in the poorly differentiated component, making a relation to intrathyroidal thymic carcinoma rather unlikely. However, since this marker was seen in the morules, a loss in the poorly differentiated component and a relation to the ultimobranchial body cannot be excluded either. After total thyroidectomy and radioiodine ablation, the patient was disease-free with no residual tumor burden on 2-year follow-up.

Tuberous sclerosis complex mutations in patients with pancreatic neuroendocrine tumors. Observations on phenotypic and treatment-related associations

Pancreatic neuroendocrine tumors (PanNETs) in familial tuberous sclerosis (TSC1 and TSC2 mutations) have been known and studied. However, little is known about PanNET patients harboring the very rare (less than 2%) sporadic TSC mutations. Some renal tumors have been shown to harbor sporadic TSC mutations, with a distinctive morphological correlate. We hereby describe this rather unusual molecular alteration in well-differentiated pancreatic neuroendocrine tumors (WD PanNETs) with a focus on their morphology and treatment outcomes. Six cases of WD PanNETs harboring sporadic TSC mutations were identified retrospectively. H&E slides and corresponding immunostains were reviewed for all cases. Clinical, molecular, and radiological information was obtained using the electronic medical records. Cohort consisted of 4 males and 2 females. Median age at diagnosis was 50 years (range 33-74 years). Origin of neoplasm was the pancreas and, in all but one, patient had liver metastasis by the time of presentation. Six out of six cases demonstrated a unique tumor morphology, with ample eosinophilic cytoplasm. Tumors were arranged in sheets and nests; prominent cystic change was noted in one case. Two cases were additionally biopsied post-treatment with capecitabine and temozolomide, and showed even more abundant oncocytic cytoplasm, eccentric nuclei, and a prominent cherry red nucleolus, and were arranged in a cluster of 3-4 cells, separated by stromal cells. Every patient had a different TSC2 variant with no cases of TSC1 mutations. Other common variants included MEN1 (4/6), DAXX (2/6), and TP53 (2/6). Per the WH0 2019 classification, tumors were graded as NET-G3 (n = 3) and NET-G2 (n = 3). Ki-67 s ranged from 7.2 to 60. All cases had retained MMR protein expression. The majority of patients (4/6) have expired. Although they received multiple treatments, a consistent pattern observed in patients was marked radiologic response to chemotherapy with capecitabine and temozolomide (offered in 5/6 patients) with duration of responses reaching 11 months in the majority of cases, with one patient showing near complete pathologic response of localized disease. TSC2 mutations may confer distinctive appearance in WD PanNETs, reminiscent of their effects in renal tumors. Although not entirely specific, this distinct morphological pattern with abundant eosinophilic cytoplasm in WD PanNETs could be reflective of an associated TSC mutation, with suggestions of significant therapeutic response to a specific cytotoxic chemotherapy.

The First Case of Cribriform-Morular Thyroid Carcinoma and FAP with APC Gene Mutation in China: A Case Report and Brief Review

The cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) is now designated as morular cribriform thyroid carcinoma (CMTC) according to the 5^th edition of the World Health Organization (WHO) Classification of Thyroid Tumors. CMTC can appear within a familial adenomatous polyposis (FAP) or be sporadic. We report the first case of a young female patient in China who was diagnosed with FAP and CMTC with a mutation in exon 16 of the APC gene underlying the disease. The main purpose of this case report is to provide a special pathological type of thyroid tumors, which is expected to be helpful for clinical work in the future.

De novo familial adenomatous polyposis associated thyroid cancer with a c.2929delG frameshift deletion mutation in APC: a case report and literature review

BACKGROUND

Germline mutations in the APC gene located on chromosome 5q 21-22 can lead to familial adenomatous polyposis (FAP) and the development of colorectal cancer (CRC) if left untreated. As a rare extracolonic manifestation, thyroid cancer is diagnosed in about 2.6% of FAP patients. The genotype-phenotype correlation in FAP patients with thyroid cancer remains unclear.

CASE PRESENTATION

We present a 20-year-old female of FAP with thyroid cancer as the initial manifestation. The patient was asymptomatic and developed colon cancer liver metastases 2 years after the diagnosis of thyroid cancer. The patient underwent multiple surgical treatments in several organs, and regular colonoscopy with endoscopic polypectomy was performed. Genetic testing demonstrated the c.2929delG (p.Gly977Valfs*3) variant in exon 15 of the APC gene. This represents a previously undescribed APC mutation. This mutation causes loss of multiple structures on the APC gene including the 20-amino acid repeats, the EB1 binding domain, and the HDLG binding site, which may be pathogenic through β-catenin accumulation, cell cycle microtubule dysregulation, and tumor suppressor inactivation.

CONCLUSIONS

We report a de novo FAP case with thyroid cancer presenting atypically aggressive features harboring a novel APC mutation and review APC germline mutations in patients with FAP-associated thyroid cancer.

Cribriform-morular thyroid carcinoma: A case report with review of the literature

Cribriform-morular thyroid carcinoma (CM-TC) is a rare entity that usually occurs in association with familial adenomatous polyposis (FAP) but may be sporadic. Herein, we present a new case of cribriform-morular thyroid carcinoma occurring in a 28-year-old woman with no history of FAP.

Papillary Thyroid Carcinoma: Current Position in Epidemiology, Genomics, and Classification

Papillary thyroid carcinoma is the most common type of thyroid malignancy both in adults and pediatric population. Since the 1980s, there are changes in criteria in labelling thyroid lesions as "papillary thyroid carcinomas." Radiation exposure is a well-established risk factor for papillary thyroid carcinoma. Other environmental risk factors include dietary iodine, obesity, hormones, and environmental pollutants. Papillary thyroid carcinomas could occur in familial settings, and 5% of these familial cases have well-studied driver germline mutations. In sporadic papillary thyroid carcinoma, BRAF mutation is common and is associated with clinicopathologic and prognostic markers. The mutation could aid in the clinical diagnosis of papillary thyroid carcinoma. Globally, thyroid cancer is among the top ten commonest cancer in females. In both adult and pediatric populations, there are variations of prevalence of thyroid cancer and rising incidence rates of thyroid cancer worldwide. The increase of thyroid cancer incidence was almost entirely due to the increase of papillary thyroid carcinoma. The reasons behind the increase are complex, multifactorial, and incompletely understood. The most obvious reasons are increased use of diagnostic entities, change in classification of thyroid neoplasms, as well as factors such as obesity, environmental risk factors, and radiation. The prognosis of the patients with papillary thyroid carcinoma is generally good after treatment. Nevertheless, cancer recurrence and comorbidity of second primary cancer may occur, and it is important to have awareness of the clinical, pathological, and molecular parameters of papillary thyroid carcinoma.

Wnt3a but not CDX-2 expression is associated with differentiated thyroid cancer

OBJECTIVE

Thyroid neoplasm incidence has increased worldwide, mostly due to the advancements in medical imaging and screening rates. The aberrant Wnt/β-catenin pathway has been identified as a key mechanism, and it has also been related to the metastatic activity of differentiated thyroid cancer. We aimed to verify the difference in the expression of Wnt3a, a canonical activator of the β-catenin signaling, and CDX-2, a transcription factor upregulated by Wnt/β-catenin pathway, in multinodular goiter and differentiated thyroid cancer and to determine their prognostic value.

METHODS

We included 194 thyroid tissue surgical specimen and their clinicopathological data: study group (differentiated thyroid cancer, n=154) and control group (multinodular goiter, n=40). Immunohistochemistry (IHC) was performed on formalin-fixed, paraffin-embedded tissue by the primary antibodies Wnt3a and CDX-2.

RESULTS

High Wnt3a expression was significantly associated with differentiated thyroid cancer (p=0.031). CDX-2 was negative in all differentiated thyroid cancer cases (100%) and also in multinodular goiter. Wnt3a expression was significantly associated with tumors ≤20 mm (p=0.044) and with the absence of capsule invasion (p=0.031). The multivariate analyses suggested that older age (≥55), independent of capsular invasion and tumor size, was an independent prognostic factor for Wnt3a expression (p=0.058).

CONCLUSIONS

Wnt3a expression but not CDX-2 is correlated with differentiated thyroid cancer samples in comparison to multinodular goiter. Although its prognostic value was limited to tumor size and capsule invasion, a combined model in a panel of immune markers can add accuracy in the classification of challenging thyroid follicular-derived lesions.

Application of Immunohistochemistry in Papillary Thyroid Carcinoma

Immunohistochemistry (IHC) is an economic and precise method to localize the presence of specific protein at cellular level in tissue. Although many papillary thyroid carcinomas do not require IHC to render a diagnosis, there are certain scenarios in which IHC are important. The major diagnostic applications of IHC include confirmation of papillary thyroid carcinoma in sites other than the thyroid, distinguish papillary thyroid carcinoma from other primary thyroid neoplasms in thyroid, and identify papillary thyroid carcinoma from secondary tumors to the thyroid. At research level, IHC could help identify prognostic information, identify underlying genetic alterations, and predict response to treatment in papillary thyroid carcinoma. The understanding of principle and recent advances in IHC will improve the diagnosis and management of patients with thyroid lesions including papillary thyroid carcinoma.

Histopathological Assessment for Papillary Thyroid Carcinoma

Histologic assessments of papillary thyroid carcinoma are crucial for management of patients with the cancer as well as research on the cancer as papillary thyroid carcinoma has different histologic subtypes and many parameters which are essential in predicting the biological aggressiveness of the cancer. The histologic assessments should be guided by universally adopted protocols including World Health Organization (WHO) classification of endocrine tumors, International Collaboration on Cancer Reporting (ICCR) dataset, American Thyroid Association initial risk stratification for differentiated thyroid carcinomas and TNM stage groupings. The essential steps in histologic assessment involve the identification of characteristic features of papillary thyroid carcinoma, correct histologic subtyping, noting the number of carcinomas, measuring the size of the carcinoma, documenting the different aggressive histological parameters (mitotic activity, presence of tumor encapsulation/circumscription, lymphatic vessel invasion, blood vessel invasion, necrosis, extrathyroidal extension), resection margin status, associated pathology, presence of parathyroid gland, lymph node and distant metastases as well as synthesis of pathological stage based on the various clinical, macroscopic, and histological features.

Emodin inhibits the proliferation of papillary thyroid carcinoma by activating AMPK

Emodin has been demonstrated to serve antitumor roles in a variety of tumor types, but the effect of emodin on papillary thyroid carcinoma and its molecular mechanisms remain unclear. In the current study, the role of emodin on papillary thyroid carcinoma was analyzed in vitro and in vivo. TPC-1 cells were treated with emodin (0, 10, 25 or 50 µM), and cell viability and apoptosis were detected using Cell Counting Kit-8 and flow cytometry, respectively. The expression levels of AMPK-associated proteins were examined using western blot analysis. To study the effect of emodin on the AMPK pathway, AMPK activator, AICAR and an AMPK inhibitor, Dorsomorphin, were used in TPC-1 cells. In vivo, mice were used to confirm the mechanism of emodin on papillary thyroid carcinoma. The results of the current study indicated that emodin treatment induced cell apoptosis and cell cycle arrest in TPC-1 cells. Furthermore, the inhibitory effect increased in a dose dependent manner. Following emodin treatment, the cell viability of TPC-1 cells was significantly decreased, and apoptosis rate increased (P<0.05). Furthermore, the expression levels of AMPK were increased in the emodin group compared with the control group (P<0.05). Similar effects were observed following AMPK activator treatment in TPC-1 cells. Following AMPK activator treatment, cell proliferation and the cell cycle were inhibited. Also, the AMPK inhibitor was demonstrated to mediate the therapeutic effect of emodin. In addition, the results of the present study demonstrated that emodin inhibited the MEK/ERK pathway. Additionally, the in vivo results of the current study were consistent with those in vitro. In conclusion, the current study demonstrated that the administration of Emodin inhibited the proliferation of papillary thyroid cancer cells via activating AMPK pathway activity.

Molecular Alterations in Pediatric Solid Tumors

Pediatric tumors can be divided into hematologic malignancies, central nervous system tumors, and extracranial solid tumors of bone, soft tissue, or other organ systems. Molecular alterations that impact diagnosis, prognosis, treatment, and familial cancer risk have been described in many pediatric solid tumors. In addition to providing a concise summary of clinically relevant molecular alterations in extracranial pediatric solid tumors, this review discusses conventional and next-generation sequencing-based molecular techniques, relevant tumor predisposition syndromes, and the increasing integration of molecular data into the practice of diagnostic pathology for children with solid tumors.

A unique case of two somatic APC mutations in an early onset cribriform-morular variant of papillary thyroid carcinoma and overview of the literature

We report a case of a 22-year-old female patient who was diagnosed with a cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC). While at early ages this thyroid cancer variant is highly suggestive for familial adenomatous polyposis (FAP), there was no family history of FAP. In the tumor biallelic, inactivating APC variants were identified. The patient tested negative for germline variants based on analysis of genomic DNA from peripheral blood leukocytes. Somatic mosaicism was excluded by subsequent deep sequencing of leukocyte and normal thyroid DNA using next generation sequencing (NGS). This report presents a rare sporadic case of CMV-PTC, and to the best of our knowledge the first featuring two somatic APC mutations underlying the disease, with an overview of CMV-PTC cases with detected APC and CTNNB1 pathogenic variants from the literature.

[The role of molecular testing in thyroid tumors]

&sup1;I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; &sup2;Endocrinology Research Centre, Moscow, Russia Thyroid cancer is the most common endocrine gland cancer. In the last few decades, the molecular diagnostics for thyroid tumors have been widely researched. It is one of the few cancers whose incidence has increased in recent years from microcarcinomas to common, large forms, in all age groups, from children to the elder people. Most researches focus on the genetic basis, since our current knowledge of the genetic background of various forms of thyroid cancer is far from being complete. Molecular and genetic research has several main directions: firstly, differential diagnosis of thyroid tumors, secondly, the prognostic value of detected mutations in thyroid cancer, and thirdly, targeted therapy for aggressive or radioactive iodine-resistant forms of thyroid cancer. In this review, we wanted to update our understanding and describe the prevailing advances in molecular genetics of thyroid cancer, focusing on the main genes associated with the pathology and their potential application in clinical practice.

Papillary thyroid carcinoma with prominent myofibroblastic stromal component: clinicopathologic, immunohistochemical and next-generation sequencing study of seven cases

Papillary thyroid carcinoma with desmoid-type fibromatosis or nodular fasciitis-like stroma is an extremely unusual and poorly understood subtype of papillary thyroid cancer. Although prior studies have demonstrated alterations in the Wnt/β-catenin signaling pathway in some of these tumors, controversy still exists regarding the nature of the stromal spindle component. We have studied seven cases of papillary thyroid carcinoma with prominent myofibroblastic stroma, including six men and one woman aged 20-65 years (mean age = 44). All cases displayed areas consistent with conventional papillary thyroid carcinoma embedded in abundant myofibroblastic-like stroma. The myofibroblastic stroma in six cases resembled desmoid-type fibromatosis and in one case it more closely resembled nodular fasciitis. By immunohistochemical staining, the stromal spindle component showed positivity for SMA and low MIB1 proliferation index in all cases, and there was at least patchy strong nuclear positivity for beta-catenin in six/seven cases. Stains for cytokeratin AE1/AE3 and PAX8 were positive in the epithelial elements but negative in the stromal component. Next-generation sequencing was performed on six of seven cases. CTNNB1 gene mutations were identified in six/seven cases. The epithelial component showed BRAF mutations in two cases and an NRAS mutation in one case. The case with fasciitis-like stroma was negative for beta-catenin by sequencing and immunostaining as well as negative for USP6 gene rearrangement. Our findings indicate that papillary thyroid carcinoma with prominent myofibroblastic stroma may represent more than one category of lesions.

Thyroid Carcinomas That Occur in Familial Adenomatous Polyposis Patients Recurrently Harbor Somatic Variants in APC, BRAF, and KTM2D

Background: Familial adenomatous polyposis (FAP) is a condition typically caused by pathogenic germline mutations in the APC gene. In addition to colon polyps, individuals with FAP have a substantially increased risk of developing papillary thyroid cancer (PTC). Little is known about the events underlying this association, and the prevalence of somatic "second-hit" mutations in APC is controversial. Methods: Whole-genome sequencing was performed on paired thyroid tumor and normal DNA from 12 FAP patients who developed PTC. Somatic mutation profiles were compared with clinical characteristics and previously sequenced sporadic PTC cases. Germline variant profiling was performed to assess the prevalence of variants in genes previously shown to have a role in PTC predisposition. Results: All 12 patients harbored germline mutations in APC, consistent with FAP. Seven patients also had somatic mutations in APC, and seven patients harbored somatic mutations in KMT2D, which encodes a lysine methyl transferase. Mutation of these genes is extremely rare in sporadic PTCs. Notably, only two of the tumors harbored the somatic BRAF p.V600E mutation, which is the most common driver mutation found in sporadic PTCs. Six tumors displayed a cribriform-morular variant of PTC (PTC-CMV) histology, and all six had somatic mutations in APC. Additionally, nine FAP-PTC patients had rare germline variants in genes that were previously associated with thyroid carcinoma. Conclusions: Our data indicate that FAP-associated PTCs typically have distinct mutations compared with sporadic PTCs. Roughly half of the thyroid cancers that arise in FAP patients have somatic "second-hits" in APC, which is associated with PTC-CMV histology. Somatic BRAF p.V600E variants also occur in some FAP patients, a novel finding. We speculate that in carriers of heterozygous pathogenic mutations of tumor suppressor genes such as APC, a cooperating second-hit somatic variant may occur in a different gene such as KTM2D or BRAF, leading to differences in phenotypes. The role of germline variance in genes other than APC (9 of the 12 patients in this series) needs further research.

Multi-omics Signatures and Translational Potential to Improve Thyroid Cancer Patient Outcome

Recent advances in high-throughput molecular and multi-omics technologies have improved our understanding of the molecular changes associated with thyroid cancer initiation and progression. The translation into clinical use based on molecular profiling of thyroid tumors has allowed a significant improvement in patient risk stratification and in the identification of targeted therapies, and thereby better personalized disease management and outcome. This review compiles the following: (1) the major molecular alterations of the genome, epigenome, transcriptome, proteome, and metabolome found in all subtypes of thyroid cancer, thus demonstrating the complexity of these tumors and (2) the great translational potential of multi-omics studies to improve patient outcome.

A rare case of the recurrent surgery for cribriform-morular variant of papillary thyroid carcinoma

INTRODUCTION

The cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) is an uncommon subtype of PTC, and it is associated with familial adenomatous polyposis (FAP).

PRESENTATION OF CASE

We describe a 32-year-old female who presented recurrent CMV-PTC with FAP. Surgery performed after the recurrent disease resulted in left recurrent laryngeal nerve palsy due to formation of strong scar after initial operation. The histopathological examination revealed the recurrent CMV-PTC without thyroid capsular invasion in remnant thyroid tissue of berry ligament. In addition, the immunohistochemical analysis showed that β-Catenin was diffusely positive in both cytoplasm and nucleus in CMV-PTC tissue.

CONCLUSION

Total thyroidectomy in CMV-PTC with FAP should be performed at initial surgery due to high recurrence.

Ectopic thyroid with benign and malignant findings: A case series

•

Thyroid heterotopy can be a cause of tumorous oropharyngeal and neck lesions.

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We present three cases of ectopic thyroid tissue with compression of the upper aerodigestive tract in the lingual area, thyroglossal duct cyst, and right submandibular region.

•

We describe clinical and imaging examinations for diagnosis and treatment.

Introduction

Ectopia is the most common sporadically occurring thyroid heterotopy. We present three cases of ectopic thyroid tissue with compression of the upper aerodigestive tract. The first case involved ectopic thyroid tissue in the lingual area of a 60-year-old male with dysphagia, swelling at the base of the tongue, and stomatolalia. The second case was a 66-year-old female with papillary thyroid carcinoma (PTC) in a thyroglossal duct cyst. The third patient was a 50-year-old female with aberrant thyroid tissue in the right submandibular region, with a cribriform-morular variant of PTC (CMV-PTC).

Methods

After resecting the heterotopic tissue and verifying the presence of PTC, the second and third cases underwent total thyroidectomy, and the third patient also underwent radioactive iodine ablation (RAI). Postoperative athyreosis was compensated by permanent levothyroxine substitution.

Results

The diagnosis of ectopic thyroid tissue is challenging. Clinical examination together with imaging methods play a key role, especially postoperative histological examination along with scintigraphy and single photon emission computed tomography (SPECT). Ultrasonography should be used to exclude normally localized thyroid tissue and to distinguish other tumorous diseases. In the pre-operative examination, ultrasound-guided fine-needle aspiration biopsy (US-FNAB) often results in technically-difficult sampling and non-diagnostic cytology.

Conclusion

Resection is the most suitable therapy for clinical symptoms of a foreign body in the upper aerodigestive tract and inflammatory complications; total thyroidectomy follows in case of malignant transformation. Thyroid heterotopy is a rare pathological condition, yet it should be taken into consideration during differential diagnosis of tumorous oropharyngeal and neck lesions.

MicroRNA-96-3p promotes metastasis of papillary thyroid cancer through targeting SDHB

Background

MicroRNA (MiRNA) is a small non-coding RNA which is implicated in a cohort of biological function in cancer, including proliferation, metastasis, apoptosis and invasion. MiR-96 has been reported to be involved in many cancers, including papillary thyroid cancer. However, the role of miR-96-3p in papillary thyroid cancer metastasis is still unclear.

Methods

qRT-PCR is used to detect the level of miR-96-3p and mRNA of SDHB in PTC tissues and cell lines. Western blot assays are used to verify the protein expression of SDHB. The transwell assays are performed to identify the migration ability of PTC cell lines. Moreover, dual-luciferase 3'-UTR reporter assays are chosen to illuminate the direct target of miR-96-3p.

Results

The relative miR-96-3p upregulate in PTC tissues and three PTC cell lines (B-CPAP, K-1 and TPC-1 cells) while the relative SDHB is opposite. Our results revealed that the miR-96-3p promotes metastasis and invasion in PTC cell lines (K-1 and TPC-1 cells) by direct targeting SDHB and influence the downstream protein AKT.

Conclusions

Taken together, the miR-96-3p is involved in PTC metastasis and invasion by direct targeting SDHB and the downstream molecule AKT and mTOR.

Influencers on Thyroid Cancer Onset: Molecular Genetic Basis

Thyroid cancer, a cancerous tumor or growth located within the thyroid gland, is the most common endocrine cancer. It is one of the few cancers whereby incidence rates have increased in recent years. It occurs in all age groups, from children through to seniors. Most studies are focused on dissecting its genetic basis, since our current knowledge of the genetic background of the different forms of thyroid cancer is far from complete, which poses a challenge for diagnosis and prognosis of the disease. In this review, we describe prevailing advances and update our understanding of the molecular genetics of thyroid cancer, focusing on the main genes related with the pathology, including the different noncoding RNAs associated with the disease.

Multifocality in a Patient with Cribriform-Morular Variant of Papillary Thyroid Carcinoma Is an Important Clue for the Diagnosis of Familial Adenomatous Polyposis

Background: Cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) is a rare subtype of PTC, which occurrs predominantly in young women. This disease much more frequently presents in patients with familial adenomatous polyposis (FAP). FAP is an autosomal dominant inherited disease, which arises from germline mutations in the adenomatous polyposis coli (APC) gene. To clarify the distinctive clinical features of CMV-PTC, a comparison study was performed between familial types and sporadic types. Methods: Between 2007 and 2018, 15 CMV-PTC patients underwent thyroidectomy in Samsung Medical Center. The clinical features of these patients were retrospectively reviewed. Results: All patients were women with a median age of 26 years (range 17-46 years). The median maximum diameter was 1.0 cm (range 0.4-3.5 cm). All tumors underwent immunostaining and showed nuclear and/or cytoplasmic staining for β-catenin. On ultrasonography, most nodules had benign-looking features (well-defined, hypoechoic, and oval to round shapes without calcification), but a few nodules had capsular invasion and taller than wide shape. On preoperative fine-needle aspiration cytology, five patients (33%) were diagnosed as CMV-PTC, nine (60%) as PTC, but one (7%) as follicular neoplasm or PTC-follicular variant. Six patients (40%) had FAP, and four of them had total colectomy due to FAP. Five of them had a family history of FAP or colon cancer, or thyroid cancer. Germline mutations in the APC gene were found in all six patients with CMV-PTC associated with FAP, and five of them had de novo mutations. All patients with FAP-associated CMV-PTC had multiple tumors. All CMV-PTC patients had excellent response to initial therapy. Conclusions: Because of the association between FAP or colon cancer with multifocal CMV-PTC, we confirm that mutational analysis of the APC gene and colonoscopy should be carried out in these patients when multiple thyroid tumors are found.

Control of Lung Metastases and Colon Polyposis with Lenvatinib Therapy in a Patient with Cribriform-Morular Variant of Papillary Thyroid Carcinoma and an APC Gene Mutation: A Case Study

Background: The cribriform-morular variant (CMV) is a rare subtype of papillary thyroid carcinoma (PTC), and is often associated with familial adenomatous polyposis (FAP). This variant is generally indolent, but some aggressive cases have been reported. Patient Findings: We present the case of a 24-year-old woman who underwent total thyroidectomy with prophylactic central lymph node dissection and modified radical neck dissection for CMV-PTC. No distant metastases were identified preoperatively. However, multiple large lung metastases were detected three and half years after surgery. She also had FAP with a germline APC gene mutation. Summary: She was started on lenvatinib because of the metastatic disease. One month after the initiation of lenvatinib (24 mg), her lung metastases reduced significantly. She has continued lenvatinib for 24 months (present dose, 10 mg). The lung metastases have not progressed during this period. Only a few small polyps were newly detected on endoscopy after lenvatinib administration. This number was considerably higher before therapy, when an average of 21-75 polyps were resected at each endoscopy session. Conclusions: This is the first report of the use of lenvatinib for the treatment of distant metastases from CMV-PTC. In addition to the efficacy in treating metastatic lesions of this rare variant of PTC, lenvatinib shows promise in the management of associated FAP. This treatment strategy may be useful in the management of recurrent CMV-PTC and in those with FAP who refuse colectomy.

Cribriform-Morular Variant of Papillary Thyroid Carcinoma Shows High Ki-67 Labeling Indices, despite Its Excellent Prognosis

OBJECTIVE

This study aimed to demonstrate that the cribriform-morular variant (CMV) of papillary thyroid carcinoma (PTC) has high Ki-67 labeling indices, despite its excellent prognosis.

METHODS

We examined 21 CMV-PTCs and 5 conventional PTCs (C-PTCs) resected at Kuma Hospital between 2008 and 2018. All of the patients with CMV-PTC were women. Their ages ranged from 17 to 35 years, with a mean of 25.2 years. An immunohistochemical study using β-catenin, estrogen receptor (ER), and Ki-67 was performed. For apoptotic analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining was performed.

RESULTS

All CMV-PTCs were encapsulated with thick fibrous connective tissue. Eleven and one CMV-PTCs exhibited capsular invasion and extrathyroidal invasion, respectively. Two patients showed regional nodal metastasis. The Ki-67 labeling index ranged from 4.8 to 36.4% (mean 15.2%). Apoptotic cells were counted, which showed 2-52 positive cells (mean 12.6) per 10 high-power fields. The Ki-67 labeling index was positively correlated with the apoptotic cell count (r = 0.48, p = 0.030). Ki-67 labeling indices of CMV-PTCs were significantly higher than those of C-PTCs (p = 0.0027). Ages and tumor sizes did not have significant correlations with Ki-67 labeling indices or apoptotic cell counts.

CONCLUSION

This study is the first to demonstrate disproportionally high Ki-67 labeling indexes in a large number of CMV-PTC cases, despite the fact that these cases had favorable prognoses. The favorable prognosis of CMV-PTC may be attributable to encapsulation and nuclear ER expression.

Cribriform-morular variant of papillary thyroid carcinoma and its association with familial adenomatous polyposis

The cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) is an uncommon variant of papillary thyroid carcinoma. CMV-PTC can be associated with familial adenomatous polyposis (FAP), an autosomal-dominant polyposis syndrome caused by a mutation in the APC gene that leads to a disruption of the Wnt/beta-catenin pathway. Understanding the relation between CMV-PTC and FAP is a diagnostic tool for both pathologists and clinicians, because FAP has several implications for patients and their families.

New and Emerging Biomarkers in Endocrine Pathology

Significant advances in genomics and molecular genetics in recent years have reshaped the practice of endocrine pathology. Pan-genomic studies, including the pioneering ones on papillary thyroid carcinoma, phaeochromocytoma/paraganglioma, and adrenal cortical carcinoma from the Cancer Genome Atlas (TCGA) project, provided a comprehensive integrated genomic analysis of endocrine tumors into distinct molecularly defined subtypes. Better understanding of the molecular landscape and more accurate definition of biological behavior has been accordingly achieved. Nevertheless, how any of these advances are translated into routine practice still remains a challenge in the era of precision medicine. The challenge for modern pathology is to keep up the pace with scientific discoveries by integrating novel concepts in tumor classification, molecular genetics, prognostication, and theranostics. As an example, pathology plays a role in the identification of hereditary disease, while it offers the tools for complementing molecular genetics, for example, validation of variants of unknown significance deriving from targeted sequencing or whole exome/genome sequencing approach. Immunohistochemistry has arisen as a cost-effective strategy in the evaluation either of somatic mutations in tumors and/or germline mutations in patients with familial cancer syndromes. Herein, a comprehensive review focusing on novel and emerging biomarkers is presented in order pathologists and other endocrine-related specialists to remain updated and become aware of potential pitfalls and limitations in the field of endocrine pathology.

Cribriform pattern in lung invasive adenocarcinoma correlates with poor prognosis in a Chinese cohort

The 2011 International　Association　for　the　Study　of　Lung　Cancer/American　Thoracic　Society/European　Respiratory　Society (IASLC/ATS/ERS) lung adenocarcinoma classification and the following 2015 WHO classification have both been validated for their predictive values of histologic subtypes for prognosis. We sought to investigate the clinicopathological and prognostic significance of the cribriform pattern in lung adenocarcinomas. Histologic subtypes were evaluated in 395 patients who underwent complete resection for invasive lung adenocarcinomas between 2011 and 2013. Cribriform pattern was correlated with clinicopathological factors as well as molecular and survival data. One hundred and thirty cases (33%) were present with cribriform pattern (5-100%; mean ± SD, 24% ± 22%). Thirty two (8%) of those were reclassified into cribriform predominant tumors. Presence of cribriform pattern (≥5%) was significantly associated with lymph/vascular invasion (P＜0.001), nodal positivity (P = 0.003), higher T stage(P = 0.005) and higher TNM stage (P = 0.001). Cribriform pattern (≥10%) was highly associated with worse disease-free survival (DFS) and overall survival (OS) (mean DFS: 42.6 months, P < 0.001; mean OS: 64.1 months, P = 0.012). The DFS or OS for cribriform predominant tumors was similar to that for solid or micropapillary tumors. In multivariate analysis, cribriform pattern (≥10%) or cribriform predominant subtype was an independent predictor for DFS. Cribriform pattern was a specific pattern compared to other acinar patterns, presenting with more aggressive behavior. Moreover, presence of cribriform pattern was a strong predictor for worse prognosis and should be considered a high grade pattern. Our study provides further evidence for cribriform pattern to be acknowledged as an independent subtype in the future classification.

Cribriform-Morular Variant of Papillary Thyroid Carcinoma: Clinical and Pathological Features of 30 Cases

BACKGROUND

Cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) is rare; it may occur in cases of familial adenomatous polyposis (FAP) or be sporadic. To clarify the clinicopathological features of CMV-PTC, the medical records of these patients were investigated retrospectively.

MATERIALS AND METHODS

Between 1979 and 2016, a total of 17,062 cases with PTC underwent initial surgery at Ito Hospital. Of these, 30 (0.2%) cases histologically diagnosed with CMV-PTC were reviewed.

RESULT

The patients were all women, with a mean age at the time of surgery of 24 years. Seven (23%) cases were thought to have FAP because they had colonic polyposis or a family history of FAP or APC gene mutation. The remaining 23 (77%) were thought to be sporadic. Multiple tumors were detected in 6 cases, with a solitary tumor in 24. One patient had lung metastasis at diagnosis. Eleven patients underwent total thyroidectomy or subtotal thyroidectomy, and 19 underwent lobectomy. Twenty-six (87%) patients underwent neck lymph node dissection. Three patients had tumor metastasis in central lymph nodes, but these were incidentally detected metastatic classical PTC (cPTC) based on histological examination. In this series, there were no cases of LN metastases of CMV-PTC. During a mean follow-up of 15 years, one patient had new cPTC in the remnant thyroid after initial surgery, and the other patients showed no signs of recurrence.

CONCLUSION

CMV-PTC occurred in young women, their long-term prognosis was excellent. Total thyroidectomy is recommended for FAP-associated CMV-PTC, but modified neck lymph node dissection is not necessary.

65 YEARS OF THE DOUBLE HELIX: Endocrine tumour syndromes in children and adolescents

As medicine is poised to be transformed by incorporating genetic data in its daily practice, it is essential that clinicians familiarise themselves with the information that is now available from more than 50 years of genetic discoveries that continue unabated and increase by the day. Endocrinology has always stood at the forefront of what is called today 'precision medicine': genetic disorders of the pituitary and the adrenal glands were among the first to be molecularly elucidated in the 1980s. The discovery of two endocrine-related genes, GNAS and RET, both identified in the late 1980s, contributed greatly in the understanding of cancer and its progression. The use of RET mutation testing for the management of medullary thyroid cancer was among the first and one of most successful applications of genetics in informing clinical decisions in an individualised manner, in this case by preventing cancer or guiding the choice of tyrosine kinase inhibitors in cancer treatment. New information emerges every day in the genetics or system biology of endocrine disorders. This review goes over most of these discoveries and the known endocrine tumour syndromes. We cover key genetic developments for each disease and provide information that can be used by the clinician in daily practice.

Characteristics of cribriform morular variant of papillary thyroid carcinoma in post-Chernobyl affected region

The aim is to study the characteristics of cribriform morular variant of papillary thyroid carcinoma (CMV-PTC) in patients living in the radiation-affected area of Belarus. The clinical and pathological features of 35 patients with CMV-PTC from Belarus were studied and compared with those of conventional papillary thyroid carcinoma diagnosed in the same period. The patients with CMV-PTC were all females and were younger at presentation (mean age = 24) than those with conventional papillary thyroid carcinoma. Familial adenomatous polyposis (FAP) was identified in 20% of the patients with CMV-PTC. The majority of the CMV-PTCs (29/35; 83%) were staged as pT1 and were less advanced than conventional papillary thyroid carcinoma. There was no evidence of lymph node metastases or distant metastases. CMV-PTCs were positive for β-catenin, APC (adenomatous polyposis coli) and p53 proteins. No psammoma bodies were identified on microscopic examination. Over a median follow-up of 9 years, all the patients were alive, and there was no cancer recurrence or mortality related to the thyroid cancer. To conclude, CMV-PTC in patients in the radiation-affected region behaves in an indolent fashion. They had distinctive features that are different from patients with conventional papillary thyroid carcinoma living in the same region.

Genomic Hallmarks of Thyroid Neoplasia

The genomic landscape of thyroid cancers that are derived from follicular cells has been substantially elucidated through the coordinated application of high-throughput genomic technologies. Here, I review the common genetic alterations across the spectrum of thyroid neoplasia and present the resulting model of thyroid cancer initiation and progression. This model illustrates the striking correlation between tumor differentiation and overall somatic mutational burden, which also likely explains the highly variable clinical behavior and outcome of patients with thyroid cancers. These advances are yielding critical insights into thyroid cancer pathogenesis, which are being leveraged for the development of new diagnostic tools, prognostic and predictive biomarkers, and novel therapeutic approaches.