Papillary thyroid carcinoma with heterotopic ossification is a special subtype with extensive progression

Overexpression of FMOD in Thyroid Carcinoma Triggers M1-Like Tumor-Associated Macrophage Polarization by Targeting Rap1B

Thyroid carcinoma, with limited efficacy of current treatment, influences the lives and health of many people. It is important to explore potential therapeutic targets for thyroid carcinoma. Fibromodulin (FMOD) has been indicated to be connected with the progression of different kinds of tumors, with unknown functions in thyroid carcinoma. In this study, the potential candidate therapeutic targets for thyroid carcinoma were identified by bioinformatics methods, and FMOD was screened out for verification. Cell counting kit-8, wound healing, transwell, and flow cytometry assays were conducted to determine the role of FMOD overexpression in cell viability, migration, invasion, and apoptotic rate of thyroid carcinoma cells, respectively. Subcutaneous tumor growth was monitored in nude mice. Tumor-associated macrophages (TAMs) were co-cultured with thyroid carcinoma cells, and the surface marker of M1-like TAMs, CD80, was identified by flow cytometry. Ras-association proximate 1B (Rap1B), the downstream target of FMOD, was predicted by bioinformatic techniques and validated by Rap1B overexpression rescue. FMOD was identified as a tumor suppressor gene in thyroid carcinoma through bioinformatic techniques. FMOD overexpression inhibited cell viability, migration, and invasion and stimulated apoptosis of thyroid carcinoma cells. In vivo, FMOD upregulation could suppress the growth of solid tumors. Moreover, FMOD overexpression in thyroid carcinoma cells promoted M1-like TAM polarization. FMOD downregulated Rap1B expression in thyroid carcinoma cells, and Rap1B overexpression rescue reversed the impact of FMOD on tumor progression and TAM polarization. In conclusion, FMOD exhibited an inhibitory effect on thyroid carcinoma by stimulating M1-like TAM polarization via targeting Rap1B.

Prognostic impact of fibrosclerotic changes in non-papillary, non-anaplastic, follicular cell-derived thyroid carcinomas

In non-papillary follicular cell-derived thyroid carcinomas, prognostic factors are scarce. Intratumoral fibrosis was identified as an adverse factor in papillary and medullary carcinomas, but it has not been investigated in other subtypes. We aimed at exploring the presence of intratumoral fibrosclerosis in a cohort of 132 non-papillary follicular cell-derived thyroid carcinomas (53 follicular and 31 oncocytic carcinomas, including 10 high grade differentiated thyroid carcinomas and 48 poorly differentiated carcinomas) and correlating its presence and extent with clinical and pathological features and survival. For each case, all available hematoxylin and eosin slides were reviewed, and the presence of fibrosclerosis was assessed as the percentage of tumor area and semi-quantitatively scored as absent, mild (≤ 10%) or extensive (> 10%). In addition, digital image analysis was applied in 65 cases. Scoring of intratumoral fibrosis showed a strong agreement between two observers and between observers and digital image quantification. The presence and extent of intratumoral fibrosis were significantly associated with poorly differentiated carcinoma histology, large tumor size, extent of vascular invasion, presence of necrosis, high mitotic index, positive nodal status, and aggressive clinical outcome, and with a shorter disease-free and disease-specific survival, the former also in follicular and oncocytic carcinomas analyzed separately. These data support the potential use of fibrosis in the clinical practice since it is both easily assessable and significantly associated with the presence of parameters of aggressiveness. In addition, fibrosis is correlated with decreased survival rate independently from the tumor histotypes, suggesting its potential role as novel prognostic factor in non-papillary follicular cell-derived thyroid carcinomas.

Heterotopic Ossification with Intrathyroidal Extramedullary Hematopoiesis in Multifocal Papillary Thyroid Carcinoma: Histopathological Findings and Literature Review

In recent decades, there has been an increase in the identification of thyroid nodules, both benign and malignant, due to the rise in imaging studies and complementary tests. Among thyroid gland tumors, papillary thyroid carcinoma (PTC) stands out as the most prevalent. Degenerative changes, mainly in the form of nodular goiter, have been recorded, occasionally including areas of calcification and, more rarely, ossification; although the latter seldom progresses to calcinosis. Ectopic bone formation, known as osseous metaplasia, is a rare phenomenon in the thyroid gland, even more so when associated with extramedullary hematopoiesis (EMH), characterized by the presence of hematopoietic elements outside the bone marrow. We present the first documented instance in our country of a patient diagnosed with malignant thyroid nodule, specifically PTC, exhibiting areas of heterotopic ossification with EMH on histopathological examination of the surgical specimen. A possible relationship between heterotopic ossification, EMH, and PTC is suggested. Various growth factors such as bone morphogenetic proteins (BMPs), specific BMP subtypes, and associated receptors could play a crucial role in initiating and developing ectopic bone formation in the context of PTC. However, further research is needed to fully elucidate its clinical significance and impact on the therapeutic management of these patients.

Blood leukocytes as a non-invasive diagnostic tool for thyroid nodules: a prospective cohort study

BACKGROUND

Thyroid nodule (TN) patients in China are subject to overdiagnosis and overtreatment. The implementation of existing technologies such as thyroid ultrasonography has indeed contributed to the improved diagnostic accuracy of TNs. However, a significant issue persists, where many patients undergo unnecessary biopsies, and patients with malignant thyroid nodules (MTNs) are advised to undergo surgery therapy.

METHODS

This study included a total of 293 patients diagnosed with TNs. Differential methylation haplotype blocks (MHBs) in blood leukocytes between MTNs and benign thyroid nodules (BTNs) were detected using reduced representation bisulfite sequencing (RRBS). Subsequently, an artificial intelligence blood leukocyte DNA methylation (BLDM) model was designed to optimize the management and treatment of patients with TNs for more effective outcomes.

RESULTS

The DNA methylation profiles of peripheral blood leukocytes exhibited distinctions between MTNs and BTNs. The BLDM model we developed for diagnosing TNs achieved an area under the curve (AUC) of 0.858 in the validation cohort and 0.863 in the independent test cohort. Its specificity reached 90.91% and 88.68% in the validation and independent test cohorts, respectively, outperforming the specificity of ultrasonography (43.64% in the validation cohort and 47.17% in the independent test cohort), albeit with a slightly lower sensitivity (83.33% in the validation cohort and 82.86% in the independent test cohort) compared to ultrasonography (97.62% in the validation cohort and 100.00% in the independent test cohort). The BLDM model could correctly identify 89.83% patients whose nodules were suspected malignant by ultrasonography but finally histological benign. In micronodules, the model displayed higher specificity (93.33% in the validation cohort and 92.00% in the independent test cohort) and accuracy (88.24% in the validation cohort and 87.50% in the independent test cohort) for diagnosing TNs. This performance surpassed the specificity and accuracy observed with ultrasonography. A TN diagnostic and treatment framework that prioritizes patients is provided, with fine-needle aspiration (FNA) biopsy performed only on patients with indications of MTNs in both BLDM and ultrasonography results, thus avoiding unnecessary biopsies.

CONCLUSIONS

This is the first study to demonstrate the potential of non-invasive blood leukocytes in diagnosing TNs, thereby making TN diagnosis and treatment more efficient in China.

Heterotopic bone formation with extramedullary haematopoiesis in a thyroid nodule

The presence of mature bone and bone marrow in the thyroid gland is an exceedingly rare occurrence. Extramedullary haematopoiesis (EMH) and heterotopic bone formation (HBF) should be suspected when cytology of thyroid nodules reveals evidence of megakaryocytes or bone marrow fat, respectively. The cause of these abnormalities has not been fully elucidated, but the role of bone morphogenic factors (BMPs) in their pathogenesis has been suggested. Both EMH and HBF can be seen in both benign and malignant primary thyroid conditions, and although they have not been definitively associated with significant pathology, it is recommended that extension studies be considered in the event of these findings to rule out concomitant haematological conditions.

Clinical and Pathological Features and Gene Expression Profiles of Clinically Aggressive Papillary Thyroid Carcinomas

Papillary thyroid carcinoma (PTC) is considered an indolent neoplasm but it may demonstrate aggressive behavior. We aimed to identify clinical and pathological characteristics and molecular signatures associated with aggressive forms of PTCs. We selected 43 aggressive PTC cases based on the presence of metastases at the time of diagnosis, the development of distant metastasis during follow-up, and/or biochemical recurrence, and 43 PTC patients that were disease-free upon follow-up, matching them according to age, sex, pT, and pN parameters. Twenty-four pairs (a total of 48 cases) and 6 normal thyroid tissues were studied using targeted mRNA screening of cancer-associated genes employing NanoString nCounter® technology. In general, aggressive PTCs showed distinctive clinical and morphological features. Among adverse prognostic parameters, the presence of necrosis and an increased mitotic index were associated with shorter disease-free and overall survivals. Other parameters associated with shorter disease-free or overall survivals include a lack of tumor capsule, the presence of vascular invasion, tumor-infiltrating lymphocytes, fibrosclerotic changes, age > 55 years, and a high pTN stage. Various pathways were differentially regulated in non-aggressive as compared to aggressive PTC, including the DNA damage repair, the MAPK, and the RAS pathways. In particular, the hedgehog pathway was differentially de-regulated in aggressive PTC as compared to non-aggressive PTC cases, being WNT10A and GLI3 genes significantly up- and down-regulated in aggressive PTC and GSK3B up-regulated in non-aggressive PTC cases. In conclusion, our study revealed specific molecular signatures and morphological features in aggressive PTC that may be useful to predict more aggressive behavior in a subset of PTC patients. These findings may be useful when developing novel, tailored treatment options for these patients.

Ossifying pilomatricoma and a novel hypothesis for its pathogenesis: A case report and comprehensive literature review

RATIONALE

Pilomatricoma is a benign skin appendageal tumor derived from hair follicle matrix cells that commonly affects the head, neck, and upper extremities of the pediatric population. Since the original tumor description, diverse variants have been reported in the literature. Pilomatricoma with florid osseous metaplasia is described as an ossifying pilomatricoma and is recognized as a distinct variant of this benign tumor. However, the pathogenesis of this variant remains unclear. In this study, we present an uncommon case of ossifying pilomatricoma and address the pathogenesis of metaplastic ossification through a comprehensive literature review.

PATIENT CONCERNS

A 14-year-old boy presented with an asymptomatic protuberant mass in the preauricular region.

DIAGNOSIS

Based on its clinicopathological features, we diagnosed the lesion as an ossifying pilomatricoma.

INTERVENTIONS AND OUTCOMES

The lesion was surgically removed under local anesthesia. The postoperative course was uneventful during the 6-month postoperative follow-up.

LESSONS

We suggest that metaplastic ossification in ossifying pilomatricoma represents another feature of foreign body reaction to keratinous materials containing shadow cells in old lesions and a walling-off phenomenon to prevent exposure of surrounding tissues to keratinous materials.

New insights on fibrodysplasia ossificans progressiva: discussion of an autoptic case report and brief literature review

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic condition with soft tissue progressive ossification, leading to severe disability. We describe a 27-years-old female affected by FOP who died after a fall. An autopsy was performed. Upper and lower extremities resulted in fixed flexion, with kyphoscoliosis of the spine and chest wall deformity. Moreover, a cranial fracture was pointed out. At histology, atypical abundance of corpora amylacea in gray matter was observed. In a sample of macroscopically non-affected muscular tissue, small areas with necrosis of myocytes and hyperplasia of fibroblasts were seen in light microscopy, with intracellular inorganic dystrophic inclusions in transmission electron microscopy. Thyroid gland histology showed diffuse lymphocytic infiltration. Postmortem examination of FOP patients provided precious information about involvement of other tissues, suggesting an initial and widespread inflammatory/dystrophic phase, to be further investigated, because it might reveal new insights about a FOP mutation cascade.

Thyroid Nodules with Isolated Macrocalcifications: Malignancy Risk of Isolated Macrocalcifications and Postoperative Risk Stratification of Malignant Tumors Manifesting as Isolated Macrocalcifications

Objective

To determine the malignancy risk of isolated macrocalcifications (a calcified nodule with complete posterior acoustic shadowing) detected on ultrasonography (US) and to evaluate the postoperative American Thyroid Association (ATA) risk stratification of malignant tumors manifesting as isolated macrocalcifications.

Materials and Methods

A total of 3852 thyroid nodules (≥ 1 cm) of 3061 consecutive patients who had undergone biopsy between January 2011 and June 2018 were included in this study. We assessed the prevalence, malignancy rate, and size distribution of isolated macrocalcifications and evaluated the histopathologic features and postoperative ATA risk stratification of malignant tumors manifesting as isolated macrocalcifications.

Results

Isolated macrocalcifications were found in 38 (1.2%) of the 3061 patients. Final diagnosis was established in 30 (78.9%) nodules; seven malignant tumors were diagnosed as papillary thyroid carcinomas (PTCs). The malignancy rate of the isolated macrocalcifications was 23.3% in the 30 nodules with final diagnoses and 18.4% in all nodules. Among the six surgically-treated malignant tumors, five (83.3%) had an extrathyroidal extension (ETE) (minor ETE 1, gross ETE 4), and two (33.3%) had macroscopic lymph node metastasis. Four (66.7%) malignant tumors were categorized as high-risk tumors, one as an intermediate-risk tumor, and one as a low-risk tumor using the ATA risk stratification. Histopathologically, out of the six malignant tumors, ossifications were noted in four (66.7%) and predominant calcifications in two (33.3%).

Conclusion

The US pattern of isolated macrocalcifications (≥ 1 cm) showed an intermediate malignancy risk (at least 18.4%). All malignant tumors were PTCs, and most showed an aggressive behavior and a high or intermediate postoperative ATA risk.

Goblet Cell Adenocarcinoma With Heterotopic Ossification: A Rare Case Report and Review of Literature

Heterotopic bone formation is a rare phenomenon when associated with gastrointestinal neoplasms. Here we present a rare case of heterotopic ossification associated with goblet cell adenocarcinoma of the appendix, and a literature review of such cases associated with neoplasms within and out of the gastrointestinal tracts. We reviewed the clinical data and when available, immunohistochemical markers of osteoblastic differentiation. Our review shows similar findings to prior reports of apparent high association of heterotopic bone formation with neoplasms with mucinous features. Two, previously proposed main hypotheses of the mechanisms are reviewed. The unique feature about this case is that goblet cell adenocarcinoma was not reported previously in the setting of bone formation.

Anatomical Assessment of the Adult Skeleton of Zebrafish Reared Under Different Thyroid Hormone Profiles

Thyroid hormone (TH) directs the growth and maintenance of tissues throughout the body during development and into adulthood, and plays a particularly important role in proper ossification and homeostasis of the skeleton. To better understand the roles of TH in the skeletogenesis of a vertebrate model, and to define areas of the skeleton that are particularly sensitive to developmental TH, we examined the effects of hypo- and hyperthyroidism on skeletal development in zebrafish. Performing a bone-by-bone anatomical assessment on the entire skeleton of adult fish, we found that TH is required for proper ossification, growth, morphogenesis, and fusion of numerous bones. We showed that the pectoral girdle, dermatocranium, Weberian apparatus, and dentary are particularly sensitive to TH, and that TH affects development of skeletal element regardless of bone type and developmental origin. Indeed, the hormone does not universally promote ossification: we found that developmental TH prevents ectopic ossification in multiple thin bones and within connective tissue of the jaw. In all, we found that TH regulates proper morphogenesis and ossification in the majority of zebrafish bones, and that the requirement for the hormone extends across bone types and developmental profiles. Anat Rec, 302:1754-1769, 2019. © 2019 American Association for Anatomy.

Multifocal papillary carcinoma of the thyroid with heterotopic ossification and extramedullary hematopoiesis associated with a lipomatous follicular nodule

Heterotopic ossification has been described in papillary thyroid carcinoma in association with high incidence of extrathyroidal invasion, multifocality, lymph node metastasis, and older age. Nevertheless, it has not been described as a specific subtype of papillary thyroid carcinoma, because of its rarity. We described the case of an 80-year-old female patient, with familial history of papillary thyroid carcinoma. In the annual screening examination, she was diagnosed with thyroid nodules. The patient was submitted to a thyroidectomy because the fine needle aspiration cytology was positive for malignancy according to the Bethesda classification. The surgical specimen analyses showed a multifocal papillary carcinoma with one major lesion in the left lobe measuring 0.9 cm, and two small lesions (0.4 cm and 0.2 cm) in the right lobe. Only the biggest lesion in the right lobe had the osteoid matrix with rare osteoclasts and fat metaplasia with progenitor cells. There was perineural invasion, but vascular invasion was not identified. The margins were free and there was no extrathyroidal extension. In the left lobe there was an oncocytic nodule and a lipomatous follicular nodule. In recent years there has been a significant increase in the diagnosis of thyroid cancer, mainly because of the finding of microcarcinomas as a result of many requests for cervical image exams. Future studies may define (i) whether papillary thyroid carcinoma with heterotopic ossification is a true histological variant; (ii) the causes of that alteration; and (iii) eventual follow-up implications.

Clinical-pathological correlations in three patients with fibrodysplasia ossificans progressiva

OBJECTIVE

Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disorder in which heterotopic bone forms in the soft tissues. This often occurs in response to injury or inflammation, leading to joint immobilization and significant disability. There are currently no definitive treatment options for this devastating disease. Although the most dramatic phenotype in FOP is the episodic and progressive heterotopic ossification, patients report a number of symptoms that affect other organ systems. Post-mortem examination of FOP patients may contribute to our understanding of the underlying pathophysiology and complications of this disease. Here, we present the autopsy findings from three patients with FOP.

FINDINGS

Autopsy findings in two of the three patients confirmed that the cause of death was cardiorespiratory failure in the setting of severe thoracic insufficiency from heterotopic ossification. Both of these patients also had evidence of right ventricular dilatation likely secondary to thoracic insufficiency. The third patient died from complications of a traumatic head injury after a fall but also had post-mortem evidence of thoracic insufficiency syndrome. All three patients had extensive, widespread heterotopic ossification and joint deformities consistent with FOP. There was extensive ossification of the spinal ligament in these patients, which may contribute to cervical spine rigidity. One patient was diagnosed post-mortem with a brainstem malformation. No additional significant abnormalities were noted in the other organ systems. Finally, we also demonstrate that cadaveric skin fibroblasts can be isolated for use as a potential source for future in vitro cell culture studies.

CONCLUSIONS

This autopsy case series provides valuable information about the underlying complications of FOP and contributes significantly to our knowledge of this rare yet debilitating disorder. Thoracic insufficiency syndrome, right heart dysfunction, widespread heterotopic ossification, spinal ligament ossification, and CNS malformations were clearly evident; however, most other non-bone tissues appeared to be spared from gross malformations. Finally, the ability to isolate live cells from cadaveric skin is an important technique that will facilitate future studies, particularly as induced pluripotent stem cells and other cell-based technologies evolve. This case series highlights the importance of post-mortem examinations and their contribution to our current knowledge of disease pathophysiology and comorbidities.

Pathologic significance of a novel oncoprotein in thyroid cancer progression

BACKGROUND

The incidence of thyroid cancer is increasing worldwide, and there is an emerging need to develop accurate tools for diagnosis. Fine needle aspiration biopsy has greatly improved evaluation of thyroid nodules, but challenges with indeterminate lesions remain in up to 25% of biopsies. Novel tissue biomarkers may assist in improved nodule characterization. Microcalcifications occurring in thyroid cancers suggest proteins involved in bone formation may play a role in thyroid carcinogenesis. We evaluated the expression of the known osteogenic protein, Enigma, in thyroid cancer as a candidate oncoprotein and role in carcinogenesis based on association with other known oncoproteins such as bone morphogenetic protein-1 (BMP-1).

METHODS

The expression of both Enigma and BMP-1 were evaluated by immunohistochemistry (IHC) in an equal number of benign (n = 120) and different histological subtypes of malignant (n = 120) human archival thyroid nodules with and without calcification. The colocalization of Enigma with BMP-1 was evaluated by confocal microscopy using the BZ analyzer.

RESULTS

Enigma was strongly expressed in thyroid cancer tissue with a higher immunoreactive score in advanced thyroid cancer compared to less advanced and benign nodules. Enigma was localized either in cytoplasm or nucleus depending on the histological subtypes. Higher expression of Enigma was associated with the tumor size and lymph node involvement. There was clear and strong colocalization signal of Enigma and that of BMP-1. Expression of Enigma occurred without regard to calcification in cancer tissue.

CONCLUSION

Enigma may serve as an oncoprotein marker, identifying benign from malignant thyroid tissue on FNA. Enigma may have a role in carcinogenesis of thyroid cancer independent of tissue calcification, possibly in relation to interaction with BMP-1.

A rare presentation: A case report of osseous metaplasia and mature bone formation in a follicular adenoma of the thyroid

•

Osseous metaplasia and bone formation may be seen in a broad spectrum of diseases involving the thyroid gland especially in malignant neoplasms of the thyroid gland.

•

However, this differentiation is not unique to malignant neoplasms. It may also be encountered in follicular adenomas of the thyroid.

•

Awareness of thyroid nodules undergoing hemorrhagic, cystic, and fibrotic changes, as well as calcification and ossification is paramount in proper diagnosis and treatment of these pathologies.

•

Particularly, patient’s history, associated risk factors and clinical presentation are the most important factors to consider in clinical differentiation of malignant and benign diagnoses.

•

All ossifications in a thyroid nodule should be considered suspicious for malignancy until proven otherwise.

Introduction

Cases of multinodular goiter, thyroid hyperplasia, follicular adenoma, papillary thyroid carcinoma, and anaplastic thyroid carcinoma have been reported with histopathologic findings of osseous metaplasia (OM), bone marrow metaplasia (BMM), ectopic bone formation (EBF), ossification, and extramedullary hematopoiesis (EMH). To date no report of a follicular adenoma with OM and mature EBF in the absence of EMH has been reported in the English language.

Presentation of case

63-year-old woman with an incidental finding of thyroid nodule unable to be biopsied. One area was found to contain OM with mature EBF and without vascular invasion. The surrounding tissue was unremarkable, and no malignancy was found.

Discussion

Ectopic bone formation and osseous metaplasia in a thyroid nodule has an extensive differential diagnosis, from thyroid related pathologies to parathyroid causes, congenital syndromes, and hamartomas. A common theory amongst these is the role of basic fibroblast growth factor (bFGF) and bone morphogenetic protein-2 (BMP-2), signaling factors involved in cellular proliferation and growth.

Conclusion

This is the first case report of a follicular adenoma with OM and EBF in the absence of EMH. In this case, this adenoma was an incidental finding and the patient had no symptoms or accompanying laboratory abnormalities. Her benign presentation underscores the importance of awareness of the more common changes a thyroid nodule can undergo, such as hemorrhagic, cystic, and fibrotic changes, as well as the rarer changes of calcification with eventual ossification.

Basic fibroblast growth factor as a potential biomarker for diagnosing malignant tumor metastasis in women

Previous studies have reported that basic fibroblast growth factor (bFGF) is associated with tumor genesis, growth and prognosis. The present study was conducted to detect the levels of bFGF expression in women with non-small cell lung cancer (NSCLC), colon cancer, breast cancer and melanoma, and analyze its association with the clinicopathological characteristics of malignant tumors. The tumor tissues were obtained from 508 female patients with malignant tumors between March 2008 and May 2015 (103 NSCLC, 147 colon cancer, 206 breast cancer and 52 melanoma). Histological examination was performed on paraffin-embedded tissues. The immunohistochemical peroxidase-conjugated streptavidin method was used to detect bFGF protein expression in the tissues. The level of bFGF protein expression was significantly increased in patients with NSCLC with poor differentiation and lymph node metastasis compared with patients with moderately/well differentiated NSCLC without lymph node metastasis. Increased levels of bFGF protein expression were observed in patients with colon cancer with lymph node metastasis compared with patients without lymph node metastasis, and in patients with breast cancer with tumor-node-metastasis stage III–IV and lymph node metastasis compared with patients in stage I–II and without lymph node metastasis. The rate of positive bFGF staining in patients with melanoma with lymph node metastasis was significantly higher compared with patients without lymph node metastasis. These results suggested that bFGF may be associated with the process of malignant tumor genesis and growth, and the expression of bFGF protein may be a potential and effective biomarker for diagnosing malignant tumor metastasis in females. The present study may also provide theoretical bases for the clinical application of bFGF monoclonal antibody in molecular targeted therapies in tumors.

Metastatic thyroid carcinoma without identifiable primary tumor within the thyroid gland: a retrospective study of a rare phenomenon

Metastatic papillary thyroid carcinoma (PTC) without an identifiable primary tumor despite extensive microscopic examination of the thyroid gland is a rare but true phenomenon.We retrieved 7 of such cases and described in detail the clinical and pathologic features of these tumors. BRAF V600E immunohistochemistry and Sequenom molecular profile were conducted in selected cases. All patients harbored metastatic disease in the central (n=3), lateral (n=3), or both neck compartments (n=1). The histotype of the metastatic disease was PTC (n=5), poorly differentiated thyroid carcinoma in association with a PTC columnar variant (n=1), and anaplastic thyroid carcinoma in association with a PTC tall cell variant (n=1). Fibrosis was present in the thyroid of 5 patients. All patients with PTC were alive without evidence of recurrence. The 76-year-old patient with poorly differentiated thyroid carcinoma did not recur and died of unknown causes. Finally, the patient with anaplastic thyroid carcinoma was alive with distant metastasis at last follow-up. The median follow-up for this cohort was 2.2years (range, 0.8-17). BRAF V600E was detected in 4 of 6 cases by immunohistochemistry. In conclusion, metastatic nodal disease without identifiable thyroid primary is a rare but real phenomenon of unknown mechanisms. Although most tumors are low grade and well differentiated, aggressive behavior due to poorly differentiated or anaplastic carcinoma can happen. Most cases are BRAF^V600E-positive thyroid tumors. A papillary carcinoma phenotype is found in all reported cases.

Primary Thyroid Carcinoma with Low-Risk Histology and Distant Metastases: Clinicopathologic and Molecular Characteristics

BACKGROUND

Distant metastases (DM) are a rare occurrence in well-differentiated thyroid carcinoma. The aim of this study was to analyze the clinical, pathologic, and molecular features of primary thyroid carcinoma with low-risk histology that develop DM.

METHODS

A detailed clinicopathologic review and targeted next-generation sequencing were performed on a cohort of well-differentiated thyroid carcinoma lacking gross extrathyroidal extension, extensive vascular invasion, or significant lymph node metastases but exhibiting DM.

RESULTS

Primary well-differentiated thyroid carcinoma with low-risk histologic features and DM was a rare occurrence, accounting for only 3% of metastatic non-anaplastic thyroid carcinoma. All 15 cases meeting the inclusion criteria harbored DM at presentation. The majority (11/15) of these tumors were follicular variant of papillary thyroid carcinoma (PTC), especially the encapsulated form (n = 8). The remaining patients harbored encapsulated Hürthle cell carcinoma (n = 2), encapsulated follicular carcinoma (n = 1), and an encapsulated papillary carcinoma classical variant (n = 1). Of the 12 encapsulated carcinomas, 10 had capsular invasion only and no vascular invasion. Ninety-two percent of the tumors exhibited extensive intra-tumoral fibrosis. Among the eight tumors that were subjected to next-generation sequencing analysis, a RAS mutation was the main driver (5/8), and TERT promoter mutation was highly prevalent (6/8). In four cases, TERT promoter mutations were associated with RAS or BRAF mutations. BRAF-mutated classical variant of papillary carcinoma also presented with DM but was less common (1/8). In 11/15 cases, the clinician was able to diagnose distant disease based on the clinical presentation. In 3/4 incidental cases that were genotyped, TERT promoter mutations were found.

CONCLUSIONS

When DM occur in primary thyroid carcinoma with low-risk histology, they are almost always found at presentation. The majority are encapsulated follicular variant of PTC with capsular invasion only. TERT promoter mutations occur at a higher rate than that seen in PTC in general and may help explain the aggressive behavior of these histologically deceptive primary carcinomas.

Extracellular Superoxide Dismutase Expression in Papillary Thyroid Cancer Mesenchymal Stem/Stromal Cells Modulates Cancer Cell Growth and Migration

Tumor stroma-secreted growth factors, cytokines, and reactive oxygen species (ROS) influence tumor development from early stages to the metastasis phase. Previous studies have demonstrated downregulation of ROS-producing extracellular superoxide dismutase (SOD3) in thyroid cancer cell lines although according to recent data, the expression of SOD3 at physiological levels stimulates normal and cancer cell proliferation. Therefore, to analyze the expression of SOD3 in tumor stroma, we characterized stromal cells from the thyroid. We report mutually exclusive desmoplasia and inflammation in papillary and follicular thyroid cancers and the presence of multipotent mesenchymal stem/stromal cells (MSCs) in non-carcinogenic thyroids and papillary thyroid cancer (PTC). The phenotypic and differentiation characteristics of Thyroid MSCs and PTC MSCs were comparable with bone marrow MSCs. A molecular level analysis showed increased FIBROBLAST ACTIVATING PROTEIN, COLLAGEN 1 TYPE A1, TENASCIN, and SOD3 expression in PTC MSCs compared to Thyroid MSCs, suggesting the presence of MSCs with a fibrotic fingerprint in papillary thyroid cancer tumors and the autocrine-paracrine conversion of SOD3 expression, which was enhanced by cancer cells. Stromal SOD3 had a stimulatory effect on cancer cell growth and an inhibitory effect on cancer cell migration, thus indicating that SOD3 might be a novel player in thyroid tumor stroma.

Bone morphogenetic protein-2 expression in an intraductal papillary mucinous neoplasm with marked ossification: A case report

Intratumoral ossification has been reported in a number of epithelial tumors, but its presence in intraductal papillary mucinous neoplasms (IPMNs) is very rare. Herein, we present a rare case of IPMN with marked ossification. A 56-year-old Japanese man was under follow-up for a previously diagnosed IPMN. Seven years later, he was found to have dilatation of the main pancreatic duct and an enlarged solid mass, for which pancreaticoduodenectomy was performed. Macroscopically, multiple and cystically dilated pancreatic branch ducts, as well as a dilated main pancreatic duct, were identified. There was a solid, polypoid hard mass measuring 15 × 12 mm in the cystically dilated branch of the duct in the pancreatic head. Histological examination revealed papillary proliferation of atypical cuboidal or columnar epithelial cells in the dilated main and branch pancreatic ducts. The solid mass included an invasive adenocarcinoma component with a tubular or trabecular structure that showed pronounced ossification. We diagnosed the patient with invasive IPMN accompanied by marked ossification. Immunohistochemically, tumor cells in both the non-invasive and invasive lesions expressed bone morphogenetic protein-2 (BMP-2). While the mechanism of intratumoral ossification is unclear, it may have involved BMP-2 in the present case.

Mesenchymal Stem/Stromal Cells in Stromal Evolution and Cancer Progression

The study of cancer biology has mainly focused on malignant epithelial cancer cells, although tumors also contain a stromal compartment, which is composed of stem cells, tumor-associated fibroblasts (TAFs), endothelial cells, immune cells, adipocytes, cytokines, and various types of macromolecules comprising the extracellular matrix (ECM). The tumor stroma develops gradually in response to the needs of epithelial cancer cells during malignant progression initiating from increased local vascular permeability and ending to remodeling of desmoplastic loosely vascularized stromal ECM. The constant bidirectional interaction of epithelial cancer cells with the surrounding microenvironment allows damaged stromal cell usage as a source of nutrients for cancer cells, maintains the stroma renewal thus resembling a wound that does not heal, and affects the characteristics of tumor mesenchymal stem/stromal cells (MSCs). Although MSCs have been shown to coordinate tumor cell growth, dormancy, migration, invasion, metastasis, and drug resistance, recently they have been successfully used in treatment of hematopoietic malignancies to enhance the effect of total body irradiation-hematopoietic stem cell transplantation therapy. Hence, targeting the stromal elements in combination with conventional chemotherapeutics and usage of MSCs to attenuate graft-versus-host disease may offer new strategies to overcome cancer treatment failure and relapse of the disease.

Role of hemithyroidectomy in differentiated thyroid cancer

PURPOSE OF REVIEW

The incidence of differentiated thyroid cancer (DTC), especially among small tumors, is increasing worldwide, despite the fact that the mortality rate from thyroid cancer remains stable. Total thyroidectomy with or without radioiodine therapy is actually the standard treatment. In the last 2 decades, several studies have shown that lobectomy could be an alternative to total thyroidectomy in low-risk DTC without compromising overall survival. The aim of this article was to assess the role of conservative surgery (hemithyroidectomy) in DTC reviewing the literature data.

RECENT FINDINGS

Recent advances in diagnostic techniques allow treatment to be tailored to patients' needs. The latest consensus guidelines suggest that patients with high-risk tumors should undergo total thyroidectomy, whereas patients with small, low-risk, node-negative DTC may be candidates for conservative surgery. Careful risk evaluation and stratification makes it possible to individualize treatment, avoid overtreatment and guarantee a good long-term prognosis with low recurrence risk. Excellent prognosis of DTC would require large sample sizes and long-term follow-up for prospective trials comparing the outcomes of total thyroidectomy vs. lobectomy; however, there are several remarkable retrospective studies.

SUMMARY

Based on current clinical data, a conservative surgery might be appropriate for patients with low-risk DTC.

Association Between BMP-2 and Carcinogenicity

STUDY DESIGN

Literature review.

OBJECTIVE

To evaluate the association between recombinant human bone morphogenetic protein-2 (rhBMP-2) and malignancy.

SUMMARY OF BACKGROUND DATA

The use of rhBMP-2 in spine surgery has been the topic of much debate as studies assessing the association between rhBMP-2 and malignancy have come to conflicting conclusions.

METHODS

A systematic review of the literature was performed using the PubMed-National Library of Medicine/National Institute of Health databases. Only non-clinical studies directly addressing BMP-2 and cancer were included. Articles were categorized by study type (animal, in vitro cell line/human/animal), primary malignancy, cancer attributes, and whether BMP-2 was pro-malignancy or not.

RESULTS

A total of 4,131 articles were reviewed. Of those, 515 articles made reference to both BMP-2 and cancer, 99 of which were found to directly examine the role of BMP-2 in cancer. Seventy-five studies were in vitro and 24 were animal studies. Forty-three studies concluded that BMP-2 enhanced cancer function, whereas 18 studies found that BMP-2 suppressed malignancy. Thirty-six studies did not examine whether BMP-2 enhanced or suppressed cancer function. Fifteen studies demonstrated BMP-2 dose dependence (9 enhancement, 6 suppression) and one study demonstrated no dose dependence. Nine studies demonstrated BMP-2 time dependence (6 enhancement, 3 suppression). However, no study demonstrated that BMP-2 caused cancer de novo.

CONCLUSION

Currently, conflicting data exist with regard to the effect of exogenous BMP-2 on cancer. The majority of studies addressed the role of BMP-2 in prostate (17%), breast (17%), and lung (15%) cancers. Most were in vitro studies (75%) and examined cancer invasiveness and metastatic potential (37%). Of 99 studies, there was no demonstration of BMP-2 causing cancer de novo. However, 43% of studies suggested that BMP-2 enhances tumor function, motivating more definitive research on the topic that also includes clinically meaningful dose- and time-dependence.

LEVEL OF EVIDENCE

2.