New Immunohistochemical Markers for Pleural Mesothelioma Subtyping

Pleural mesothelioma (PM) comprises three main subtypes: epithelioid, biphasic and sarcomatoid, which have different impacts on prognosis and treatment definition. However, PM subtyping can be complex given the inter- and intra-tumour morphological heterogeneity. We aim to use immunohistochemistry (IHC) to evaluate five markers (Mesothelin, Claudin-15, Complement Factor B, Plasminogen Activator Inhibitor 1 and p21-activated Kinase 4), whose encoding genes have been previously reported as deregulated among PM subtypes. Immunohistochemical expressions were determined in a case series of 73 PMs, and cut-offs for the epithelioid and non-epithelioid subtypes were selected. Further validation was performed on an independent cohort (30 PMs). For biphasic PM, the percentage of the epithelioid component was assessed, and IHC evaluation was also performed on the individual components separately. Mesothelin and Claudin-15 showed good sensitivity (79% and 84%) and specificity (84% and 73%) for the epithelioid subtype. CFB and PAK4 had inferior performance, with higher sensitivity (89% and 84%) but lower specificity (64% and 36%). In the biphasic group, all markers showed different expression when comparing epithelioid with sarcomatoid areas. Mesothelin, Claudin-15 and CFB can be useful in subtype discrimination. PAI1 and PAK4 can improve component distinction in biphasic PM.

SMARCA4 as a support for the differential diagnosis of poorly differentiated lung carcinomas

Among non-small cell lung cancers (NSCLCs), sarcomatoid carcinomas account for 3%. They are rare tumours with a poor prognosis, classified into three subgroups, namely pleomorphic carcinoma, pulmonary blastoma and carcinosarcoma. In the 5th edition of WHO Classification of Thoracic Tumours more space is given to SMARC4-deficient lung cancers. Although studies on SMARCA4-deficient lung tumours are limited, a small percentage of SMARCA4 loss is present within NSCLCs. This finding is clinically relevant, as the loss of the SMARCA4 gene is associated with a worse prognosis. In our study, we analysed the presence of the main catalytic subunit of the SMARCA4 gene, the BRG1 protein, in 60 sarcomatoid lung tumours. The results of our study show that 5.3% of sarcomatoid carcinomas have BRG1-loss in tumour cells, proving that a non-negligible amount of lung sarcomatoid carcinomas are SMARCA4-deficient. These data open the debate on the necessity of including the detection of SMARCA4 within a standardised immunohistochemical panel.

Outcomes of the Tall-Cell Variant of Papillary Thyroid Carcinoma in Patients with Different Ages: A 17-Year Mono-Institutional Experience

The tall-cell variant of papillary thyroid carcinoma (TCPTC) is the most common aggressive variant of papillary thyroid carcinoma (PTC) and typically occurs in older patients. In this study, we analyzed retrospectively the largest mono-institutional series of PTCs with tall-cell features (989 patients) over a 17-year period, re-evaluating tumors based on age at presentation and outcomes in different age groups. We divided patients into three age groups following different criteria (the criterion from the American Joint Committee on Cancer Tumor Node Metastasis (AJCC TNM) guidelines, criterion for the statistical division into tertiles and adolescent/post-adolescent criterion) to analyze the clinicopathological characteristics in different age groups, especially in terms of recurrence-free survival (RFS) and distant recurrence-free survival (DRFS). We obtained three main results: 1. the population is distributed among the different age groups, and therefore, this type of cancer is not exclusively found among those of an older age; 2. in the RFS analysis, we can see a higher probability of local recurrence in the younger and older groups and, unexpectedly, a lower probability of local recurrence in the “median age” group; and 3. in the DRFS analysis, we can observe a higher probability of distant recurrence in older patients. From a molecular perspective, no significant differences in the mutational status of BRAF were detected according to different age groups, while mutations in the TERT promoter were exclusively present in older patients of all age groups, highlighting the potential prognostic implications of TERT promoter mutations in PTCs. In conclusion, the results of this series confirm that TC morphology alone in PTCs does not have the same negative prognostic significance in the younger population as in the older population. The reason for these different outcomes remains unclear and needs further studies.

Thyroid Metastasis from Primary Breast Cancer

Breast cancer (BC), the most commonly diagnosed malignancy, frequently metastasizes to the bone, lungs, brain and liver at advanced stages, whereas the thyroid gland represents a rare target site for secondary disease. We examined the most recent literature about thyroid metastasis (TM) from BC after we encountered a peculiar case of a 71-year-old woman who developed sudden dysphagia, severe hypothyroidism and hypoparathyroidism due to TM 18 years after the diagnosis of her primary cancer. Based on published data, the prevalence of TM in BC ranges from 3% to 34%, with a median onset time of 48.2 months, although longer time intervals are not infrequent. TM negatively impacts the prognosis of these patients, however thyroid surgery can limit the local disease burden. Therefore, we suggest that clinicians involved in the follow-up care of BC patients should consider a differential diagnosis of secondary thyroid malignancy when incidental lesions are diagnosed during radiological evaluations or local symptoms affect the cervical region, even many years after the diagnosis of the primary cancer.

Dissecting tumor lymphocyte infiltration to predict benefit from immune-checkpoint inhibitors in metastatic colorectal cancer: lessons from the AtezoT RIBE study

BACKGROUND

Tumor immune cells influence the efficacy of immune-checkpoint inhibitors (ICIs) and many efforts aim at identifying features of tumor immune microenvironment able to predict benefit from ICIs in proficient mismatch repair (pMMR)/microsatellite stable (MSS) metastatic colorectal cancer (mCRC).

METHODS

We characterized tumor immune cell infiltrate, by assessing tumor-infiltrating lymphocytes (TILs), Immunoscore, Immunoscore-IC, and programmed death ligand-1 (PD-L1) expression in tumor samples of patients with mCRC enrolled in the AtezoTRIBE study, a phase II randomized trial comparing FOLFOXIRI/bevacizumab/atezolizumab to FOLFOXIRI/bevacizumab, with the aim of evaluating the prognostic and predictive value of these features.

RESULTS

Out of 218 patients enrolled, 181 (83%), 77 (35%), 157 (72%) and 162 (74%) specimens were successfully tested for TILs, Immunoscore, Immunoscore-IC and PD-L1 expression, respectively, and 69 (38%), 45 (58%), 50 (32%) and 21 (13%) tumors were classified as TILs-high, Immunoscore-high, Immunoscore-IC-high and PD-L1-high, respectively. A poor agreement was observed between TILs and Immunoscore or Immunoscore-IC (K of Cohen <0.20). In the pMMR population, longer progression-free survival (PFS) was reported for Immunoscore-high and Immunoscore-IC-high groups compared with Immunoscore-low (16.4 vs 12.2 months; HR: 0.55, 95% CI: 0.30 to 0.99; p=0.049) and Immunoscore-IC-low (14.8 vs 11.5 months; HR: 0.55, 95% CI: 0.35 to 0.85; p=0.007), respectively, with a significant interaction effect between treatment arms and Immunoscore-IC (p for interaction: 0.006) and a trend for Immunoscore (p for interaction: 0.13). No PFS difference was shown according to TILs and PD-L1 expression. Consistent results were reported in the overall population.

CONCLUSIONS

The digital evaluation of tumor immune cell infiltrate by means of Immunoscore-IC or Immunoscore identifies the subset of patients with pMMR mCRC achieving more benefit from the addition of the anti-PD-L1 to the upfront treatment. Immunoscore-IC stands as the most promising predictor of benefit from ICIs.

Autopsy Study of Testicles in COVID-19: Upregulation of Immune-Related Genes and Downregulation of Testis-Specific Genes

CONTEXT

Infection by SARS-CoV-2 may be associated with testicular dysfunction that could affect male fertility.

OBJECTIVE

Testicles of fatal COVID-19 cases were investigated to detect virus in tissue and to evaluate histopathological and transcriptomic changes.

METHODS

Three groups were compared: (a) uninfected controls (subjects dying of trauma or sudden cardiac death; n = 10); (b) subjects dying of COVID-19 (virus-negative in testes; n = 15); (c) subjects dying of COVID-19 (virus-positive in testes; n = 9). SARS-CoV-2 genome and nucleocapsid antigen were probed using RT-PCR, in situ hybridization, and immunohistochemistry (IHC). Infiltrating leukocytes were typed by IHC. mRNA transcripts of immune-related and testis-specific genes were quantified using the nCounter method.

RESULTS

SARS-CoV-2 was detected in testis tissue of 9/24 (37%) COVID-19 cases accompanied by scattered T-cell and macrophage infiltrates. Size of testicles and counts of spermatogenic cells were not significantly different among groups. Analysis of mRNA transcripts showed that in virus-positive testes immune processes were activated (interferon-alpha and -gamma pathways). By contrast, transcription of 12 testis-specific genes was downregulated, independently of virus positivity in tissue. By IHC, expression of the luteinizing hormone/choriogonadotropin receptor was enhanced in virus-positive compared to virus-negative testicles, while expression of receptors for androgens and the follicle-stimulating hormone were not significantly different among groups.

CONCLUSION

In lethal COVID-19 cases, infection of testicular cells is not uncommon. Viral infection associates with activation of interferon pathways and downregulation of testis-specific genes involved in spermatogenesis. Due to the exceedingly high numbers of infected people in the pandemic, the impact of virus on fertility should be further investigated.

Trop-2 and Nectin-4 immunohistochemical expression in metastatic colorectal cancer: searching for the right population for drugs' development

BACKGROUND

Trop-2 and Nectin-4 are transmembrane proteins overexpressed in many tumours and targets of antibody-drug conjugates (ADC). In metastatic colorectal cancer (mCRC), the role of Trop-2 and Nectin-4 has been poorly investigated.

METHODS

Tumour samples of patients randomised in the phase III TRIBE2 were assessed for Trop-2 and Nectin-4 expression.

RESULTS

Three hundred eighty-six tumours were assessed for Trop-2 expression. 90 (23%), 115 (30%) and 181 (47%) were Trop-2 high, medium and low, respectively. Patients with low Trop-2 tumours achieved longer PFS (12 versus 9.9 months, p = 0.047) and OS (27.3 versus 21.3 months, p = 0.015) than those with high/medium Trop-2 tumours. These findings were confirmed in multivariate analysis (p = 0.022 and p = 0.023, respectively). A greater OS benefit from treatment intensification with FOLFOXIRI/bevacizumab was observed in patients with high/medium Trop-2 tumours (p-for-interaction = 0.041). Two hundred fifty-one tumours were assessed for Nectin-4 expression. Fourteen (5%), 67 (27%) and 170 (68%) were high, medium and low, respectively. No prognostic impact was observed based on Nectin-4 expression and no interaction effect was reported between Nectin-4 expression groups and treatment arm.

CONCLUSIONS

In mCRC, expression levels of Trop-2 and Nectin-4 are heterogeneous, suggesting a target-driven development of anti-Trop2 and anti-Nectin-4 ADCs. Medium/high Trop-2 expression is associated with worse prognosis and higher benefit from chemotherapy intensification.

MicroRNA expression profiling of RAS-mutant thyroid tumors with follicular architecture: microRNA signatures to discriminate benign from malignant lesions

PURPOSE

RAS mutations represent common driver alterations in thyroid cancer. They can be found in benign, low-risk and malignant thyroid tumors with follicular architecture, which are often diagnosed as indeterminate nodules on preoperative cytology. Therefore, the detection of RAS mutations in preoperative setting has a suboptimal predictive value for malignancy. In this study, we investigated differentially expressed microRNA (miRNA) in benign and malignant thyroid tumors with follicular architecture carrying mutations in RAS genes.

METHODS

Total RNA was purified from 60 RAS-mutant follicular-patterned thyroid tumors, including follicular adenoma (FA), noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), papillary and follicular thyroid carcinoma cases (PTC, FTC); 22 RAS-negative FAs were used as controls. The expression analysis of 798 miRNAs was performed by digital counting (nCounter nanoString platform).

RESULTS

Comparing RAS-mutant and RAS-negative FAs, 12 miRNAs showed significant deregulation, which was likely related to the oncogenic effects of RAS mutations. Twenty-two miRNAs were differentially expressed in RAS-mutant benign versus malignant tumors. Considering the tumor type, 24 miRNAs were deregulated in PTC, 19 in NIFTP, and seven in FTC and compared to FA group; among these, miR-146b-5p, miR-144-3p, and miR-451a showed consistent deregulation in all the comparisons with the highest fold change.

CONCLUSIONS

The miRNA expression analysis of follicular-patterned thyroid tumors demonstrated that RAS mutations influences miRNA profile in benign tumors. In addition, several miRNAs showed a histotype-specific deregulation and could discriminate between RAS-mutant benign and RAS-mutant malignant thyroid lesions, thus deserving further investigation as potential diagnostic markers.

The Italian Consensus for the Classification and Reporting of Thyroid Cytology: Cytohistologic and molecular correlations on 37,371 nodules from a single institution

BACKGROUND

The Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) includes six diagnostic categories (TIR 1/1C, TIR 2, TIR 3A, TIR 3B, TIR 4, and TIR 5), each indicating a different risk of malignancy. The objective of this monocentric retrospective study was to evaluate the distribution of the ICCRTC classes at the authors' institution and assess their cytohistologic correlations.

METHODS

The authors retrospectively collected 37,371 consecutive cytologic reports of thyroid nodules and described the clinical-pathologic features of the different cytologic categories. The cytologic diagnoses also were compared with histologic outcomes in a subset of patients.

RESULTS

The cytologic classes were distributed as follows: nondiagnostic, 15.6%; benign, 66.5%; low-risk indeterminate, 10% (TIR 3A); high-risk indeterminate, 3.5% (TIR 3B); suspicious, 1.7%; and malignant, 2.6%. According to histology, the risk of malignancy was very high in the nondiagnostic category (29.8%), with young male patients more exposed to malignancy, and it was relatively high among benign (7.8%) and indeterminate nodules (32.5% in TIR 3A; 52.1% in TIR 3B), mainly because of the high prevalence of follicular architecture in malignant tumors. On histology, the malignancy rates were 92.4% and 99.3% for the suspicious and malignant categories, respectively; aggressive variants of papillary thyroid carcinoma were mostly diagnosed in these categories.

CONCLUSIONS

In this series, nondiagnostic nodules showed high prevalence and, surprisingly, high malignancy rates. Malignant tumors with follicular architecture represented a diagnostic pitfall in benign and indeterminate nodules. The suspicious and malignant categories had high specificity for malignancy. Importantly, the ICCRTC had high reliability for identifying preoperatively aggressive histotypes of thyroid carcinoma.

Barking up the Right Tree: Using Tree Bark to Track Airborne Particles in School Environment and Link Science to Society

Children's exposure to air pollution affects both their health and learning skills. Fine and ultrafine particulate matter (PM2.5, PM1), notably issued from traffic sources in urban centers, belong to the most potential harmful health hazards. However their monitoring and the society's awareness on their dangers need to be consolidated. In this study, raising teacher and pupil involvement for air quality improvement in their schools environment is reached through developing a passive monitoring technique (bio-sensors made of tree bark). The experiment was implemented in two urban elementary schools situated close to a main traffic road of the city of Toulouse (South of France). Magnetic properties, carbonaceous fraction measurements, and scanning electronic microscopy (SEM-EDX) investigations were realized both on passive bio-sensors and filters issued from active sampling. We find that traffic is the main PM1 source for both outdoors and indoors at schools. Higher levels of outdoor PM in the school's environments compared to urban background are reached especially in the cold period. The schools proximity to a main traffic source and lack of ventilation are the main causes for observed PM1 accumulation in classrooms. The co-working experiment with educational teams and pupils shows that the use of bio-sensors is a driver for children empowerment to air pollution and therefore represents a potential key tool for the teachers though limiting eco-anxiety. As PM accumulation is observed in many scholar environments across Europe, the proposed methodology is a step toward a better assessment of PM impact on pupil's health and learning skills.

Suppression of Pituitary Hormone Genes in Subjects Who Died From COVID-19 Independently of Virus Detection in the Gland

CONTEXT

Involvement of the pituitary gland in SARS-CoV-2 infection has been clinically suggested by pituitary hormone deficiency in severe COVID-19 cases, by altered serum adrenocorticotropic hormone (ACTH) levels in hospitalized patients, and by cases of pituitary apoplexy. However, the direct viral infection of the gland has not been investigated.

OBJECTIVE

To evaluate whether the SARS-CoV-2 genome and antigens could be present in pituitary glands of lethal cases of COVID-19, and to assess possible changes in the expression of immune-related and pituitary-specific genes.

METHODS

SARS-CoV-2 genome and antigens were searched in the pituitary gland of 23 patients who died from COVID-19 and, as controls, in 12 subjects who died from trauma or sudden cardiac death. Real-time reverse transcription polymerase chain reaction (PCR), in situ hybridization, immunohistochemistry, and transmission electron microscopy were utilized. Levels of mRNA transcripts of immune-related and pituitary-specific genes were measured by the nCounter assay.

RESULTS

The SARS-CoV-2 genome and antigens were detected in 14/23 (61%) pituitary glands of the COVID-19 group, not in controls. In SARS-CoV-2-positive pituitaries, the viral genome was consistently detected by PCR in the adeno- and the neurohypophysis. Immunohistochemistry, in situ hybridization, and transmission electron microscopy confirmed the presence of SARS-CoV-2 in the pituitary. Activation of type I interferon signaling and enhanced levels of neutrophil and cytotoxic cell scores were found in virus-positive glands. mRNA transcripts of pituitary hormones and pituitary developmental/regulatory genes were suppressed in all COVID-19 cases irrespective of virus positivity.

CONCLUSION

Our study supports the tropism of SARS-CoV-2 for human pituitary and encourages exploration of pituitary dysfunction after COVID-19.

Down-regulation of miR-7-5p and miR-548ar-5p predicts malignancy in indeterminate thyroid nodules negative for BRAF and RAS mutations

PURPOSE

The value of molecular markers in refining preoperative risk assessment of indeterminate thyroid nodules is being widely investigated. MicroRNAs (miRNA) are emerging as promising biomarkers for diagnostic and prognostic purposes. The aim of this study is to identify miRNAs specifically deregulated in mutation-negative indeterminate thyroid nodules.

METHODS

Ninety-eight nodules preoperatively diagnosed as TIR 3A or TIR 3B with available histological diagnosis of follicular adenoma (FA), noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP), and follicular variant papillary thyroid carcinoma (FV-PTC) have been retrospectively selected. Mutations in BRAF and RAS genes have been tested in all samples by real-time PCR; miRNAs were purified from cytology slides of 60 samples; expression analysis of 798 miRNAs was measured by the nCounter system.

RESULTS

Point mutations in BRAF and RAS genes were detected in 32 out of 98 nodules (32.7%), the majority of which in FV-PTCs. Differential expression of miRNA in wild-type nodules highlighted that two miRNAs, namely miR-7-5p and miR-548ar-5p, were downregulated in FV-PTCs compared to FAs. The combined expression of these miRNAs, tested by ROC analysis, showed an area under the curve of 0.79. Sensitivity and negative predictive value were high both in wild-type (93% and 92%, respectively) and in mutated nodules (94% and 85%, respectively).

CONCLUSION

The analysis of miR-7-5p and miR-548ar-5p expression in indeterminate thyroid nodules demonstrated a promising value in ruling out malignancy.

Predictive Biomarkers in Thyroid Cancer

In molecular pathology, predictive biomarkers identify which patients are likely to respond to targeted drugs. These therapeutic agents block specific molecules directly involved in cancer growth, dedifferentiation and progression. Until few years ago, the only targeted drugs available for advanced thyroid cancer included multi-tyrosine kinase inhibitors, mainly targeting the MAPK pathway and the angiogenic signaling. The administration of these drugs does not necessarily require a molecular characterization of tumors to assess the presence of predictive alterations. However, the availability of new selective targeted drugs for thyroid cancer patients is changing the diagnostic strategies for the molecular characterization of these tumors. The search for targetable alterations can be performed directly on tumor tissue by using a variety of methodologies, depending also on the number and type of alterations to test (i.e. single nucleotide variation or gene rearrangement). Herein, a comprehensive review of the currently available targeted treatments for thyroid cancer, related predictive markers and testing methodologies is provided.

Adipose tissue in COVID-19: detection of SARS-CoV-2 in adipocytes and activation of the interferon-alpha response

OBJECTIVE

Obesity is a recognized risk factor for the progression to severe forms of COVID-19, yet the mechanisms of the association are unclear.

METHODS

Subcutaneous abdominal adipose tissue specimens of subjects deceased from COVID-19 (n = 23) were compared to those of controls dying abruptly from causes other than infectious (accidental trauma, sudden cardiac death). Alterations of lung parenchyma consistent with moderate to severe disease were detected in all COVID-19 cases, not in controls. Investigations included: histopathologic features, detection of virus antigens and genome, characterization of infiltrating leukocytes, transcription levels of immune-related genes.

RESULTS

By RT-PCR, the SARS-CoV-2 genome was detected in the adipose tissue of 13/23 (56%) cases of the COVID-19 cohort. The virus nucleocapsid antigen was detected in the cytoplasm of 1-5% adipocytes in 12/12 COVID-19 cases that were virus-positive by PCR in the adipose tissue (one case could not be assessed due insufficient tissue). The adipose tissue of COVID-19 cases showed leukocyte infiltrates and upregulation of the interferon-alpha pathway. After adjusting for age and sex, the activation score of IFN-alpha was directly related with transcription levels of the ACE2 gene, a key entry factor of SARS-CoV-2.

CONCLUSIONS

In lethal COVID-19 cases, the SARS-CoV-2 nucleocapsid antigen has been detected in a sizeable proportion of adipocytes, showing that the virus may directly infect the parenchymal cells of subcutaneous fat. Infection appears to activate the IFN alpha pathway and to attract infiltrating leukocytes. Due to the huge numbers of adipocytes in adults, the adipose tissue represents a significant reservoir for SARS-CoV-2 and an important source of inflammatory mediators.

Intestinal Ischemia: Unusual but Fearsome Complication of COVID-19 Infection

The pathophysiology of gastrointestinal damage in coronavirus disease (COVID-19) is probably multifactorial. It is not clear whether the etiology of intestinal ischemia may be directly related to viral replication or may result from hyper-coagulability following SARS-CoV-2 infection.To confirm a pathogenic role of COVID-19, we retrospectively investigated the presence of SARS-CoV-2 virus in the ischemic bowel of five COVID-19 patients undergoing emergency surgery for intestinal ischemia in the period of March 2020-May 2021. Immunohistochemical positivity with weak intensity was observed in four out of five cases, but only one case was strongly positive both at immunohistochemistry and at molecular analysis. The histological alterations in the intestinal tissue samples showed similarity with the well-known alterations described in typical targetorgans of the virus (e.g., the lung). This observation suggests a similar mechanism of action of the virus. Further larger studies are, thus, required to confirm this preliminary finding. Clinicians should carefully monitor all COVID-19 patients for the possible presence of a SARS-CoV-2 intestinal infection, a potential cause of ischemia and bowel perforation.

Inflammatory Profiles of Tracheal Biopsies From SARS-CoV-2 Patients

Purpose

An increasing number of laryngotracheal complications in mechanically ventilated COVID-19 patients has been reported in the last few months. Many etiopathogenetic hypotheses were proposed but no clear explanation of these complications was identified. In this paper we evaluated the possibility that the tracheal mucosa could be a high viral replication site that could weaken the epithelium itself.

Methods

Subjects for the COVID-19 group and the control group were selected retrospectively according to specific criteria. Patients’ basic and clinical data were recorded and analyzed. Tracheal samples of both groups were collected during surgical tracheostomies and then analyzed from a histological and genetic-transcriptional point of view.

Results

Four COVID-19 patients were enrolled in this study and compared with four non-COVID-19 patients. No laryngotracheal complications were identified in both groups. The SARS-CoV-2 was detected in one out of four COVID-19 samples. A subepithelial inflammatory lymphomonocyte infiltrate was observed in all patients but two cases of the COVID-19 group showed vasculitis of small subepithelial vessels associated with foci of coagulative necrosis. Two gene sets (HALLMARK_INFLAMMATORY_RESPONSE and HALLMARK_ESTROGEN_RESPONSE_LATE) were significantly deregulated in COVID-19 patients compared to the control group.

Conclusion

The altered inflammatory response of the COVID-19 patients could be another possible explanation of the increasing number of laryngotracheal complications.

Clinical-Pathological and Molecular Evaluation of 451 NIFTP Patients from a Single Referral Center

BACKGROUND

Non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTPs) were introduced in thyroid pathology in 2016. NIFTPs are a group of follicular neoplasm with an indolent behaviour. In this study, we gathered a large retrospective cohort of NIFTPs and compared those presenting as solitary lesions and NIFTPs found in multifocal setting.

METHODS

A retrospective search of NIFTPs was performed, and the clinico-pathological features were recorded. For a subgroup of patients, pre-surgical ultrasound (US) evaluation, cytological diagnosis, and molecular analysis were available.

RESULTS

We collected 451 NIFTPs; 254 (56.3%) were truly solitary tumours, while 197 coexisted with one or more NIFTP/cancer. Contrasting unifocal and multifocal settings, NIFTPs size was the only significantly different parameter. Preoperatively, NIFTP nodules mostly showed low-risk US characteristics, indeterminate cytology and a RAS-like molecular profile.

CONCLUSION

NIFTPs often coexist with collateral thyroid tumours. However, no clinical-pathological differences can be observed between solitary and "multifocal" NIFTPs. Despite the well-established clinical indolence of NIFTP, a careful monitoring of the contralateral lobe should not be excluded.

COVID-19 autopsy cases: detection of virus in endocrine tissues

PURPOSE

The SARS-CoV-2 genome has been detected in a variety of human samples including blood, urine, semen, and faeces. However, evidence of virus presence in tissues other than lung are limited.

METHODS

We investigated whether SARS-CoV-2 could be detected in 50 autoptic specimens of endocrine organs from 29 patients who died of COVID-19.

RESULTS

The virus was detected in 25 specimens including ten abdominal subcutaneous adipose tissue samples (62%), six testes (67%), and nine thyroid (36%) samples. The analysis of multiple endocrine organ samples obtained from the same patients showed that, in virus-positive cases, the viral genome was consistently detected in all but two matched specimens.

CONCLUSION

Our findings show that the virus spread into endocrine organs is a common event in severe cases. Further studies should assess the rate of the phenomenon in clinically mild cases. The potential long-term effects of COVID-19 on endocrine functions should be taken into consideration.

Clinical-Pathological Features and Treatment Outcome of Patients With Hobnail Variant Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC) with hobnail areas above 30% is classified as hobnail variant (HVPTC). Although it is widely accepted that HVPTC has a worse outcome than classical PTC, it is unclear whether PTC with hobnail features below 30% is as aggressive as HVPTC. We gathered the largest mono-institutional series of PTC with hobnail areas and HVPTC to evaluate differences in terms of pathological features of aggressiveness, molecular profile, and treatment outcome. A total of 99 PTC with hobnail features above 5% were retrospectively selected; 34 of them met the criteria for HVPTC (0.4% of all PTC diagnosed at our institution). All tumors showed high rates of extra-thyroidal extension (40.4%), lymph node metastasis (68.1% of patients with lymphadenectomy), and vascular emboli (49.5%), with no differences according to the 30% cutoff. On the other hand, distant metastases were present in HVPTC only (9.4%). Also, advanced age, advanced disease stage, and TERT promoter mutation were associated with HVPTC. More than half of the patients with follow-up had structural or biochemical persistence after 1 year from surgery. Structural persistence was significantly more common in patients with HVPTC (37.5% vs. 8.7%), while no differences were observed considering structural and biochemical persistence together. The presence of hobnail features identifies locally aggressive tumors, and, consequently, it should be always acknowledged in the pathological report. However, tumors with more than 30% hobnail areas frequently present TERT promoter mutations, advanced disease stage, and structural persistence after radioiodine ablation.

Activation of Type I and Type II Interferon Signaling in SARS-CoV-2-Positive Thyroid Tissue of Patients Dying from COVID-19

Background: Thyroid dysfunctions have been reported after Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. However, the biological mechanisms behind these conditions remain unexplored. Herein, we report on changes of the immune transcriptome in autoptic thyroid tissues of people who have died from coronavirus disease 2019 (COVID-19). Methods: Twenty-five autoptic thyroid specimens of subjects dying from COVID-19 were investigated. Eleven autoptic thyroid specimens of subjects dying from causes other than infectious conditions served as controls. RNA transcripts of 770 immune-related genes together with RNA genomes of multiple coronavirus types were measured by the nCounter system. Reverse transcription-polymerase chain reaction for two SARS-CoV-2 genes was used to assess virus positivity. Results were validated by immunohistochemistry. Results: The SARS-CoV-2 genome and antigens were detected in 9 of 25 (36%) thyroid specimens from the COVID-19 cohort. Virus-negative thyroid tissues from COVID-19 subject did not show changes of gene transcription nor significant numbers of infiltrating immune cells. Conversely, SARS-CoV-2-positive thyroid specimens showed marked upregulation of immune genes, especially those proper of the type I and type II interferon (IFN) pathways. In infected tissues, infiltrates of innate immune cells (macrophages and polymorphonuclear neutrophils) were prevalent. Conclusions: The thyroid gland can be directly infected by the SARS-CoV-2. Infection strongly activates IFN pathways. The direct viral insult combined with an intense immune response may trigger or worsen thyroid conditions in predisposed individuals.

Prevalence of Delta-Like Protein 3 in a Consecutive Series of Surgically Resected Lung Neuroendocrine Neoplasms

Delta-like protein 3 (DLL3) is a protein of the Notch pathway, and it is a potential therapeutic target for high-grade lung neuroendocrine tumors (NETs), i.e., small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC). However, DLL3 prevalence in lung NETs and its association with clinicopathological characteristics and prognosis remained unclear. We analyzed the immunohistochemical expression of DLL3 and its prognostic role in a consecutive series of 155 surgically resected lung NETs, including typical carcinoid (TC), atypical carcinoid (AC), LCNEC, and SCLC patients. The DLL3 expression was categorized as high (>50% positive tumor cells) or low (<50%). In addition, tumors were categorized by H-score (i.e., percentage of positive cells by staining intensity, ≥150 vs. <150). DLL3 staining was positive in 99/155 (64%) samples, and high DLL3 expression was frequently observed in high-grade tumors. In detail, 46.9% and 75% of SCLC and 48.8% and 53.7% of LCNEC specimens showed a high DLL3 expression by using H-score and percentage of positive tumor cells, respectively. Regarding low-grade NETs, only 4.9% and 12.2% TCs and 19.5% and 24.4% ACs had high DLL3 expression considering H-score and percentage of positive tumor cells, respectively. High DLL3 expression was associated with advanced American Joint Committee on Cancer (AJCC) stage, peripheral location, and chromogranin A expression in high-grade tumors (p < 0.05). In low-grade NETs, high DLL3 expression was associated with female sex, peripheral location, a higher number of mitoses, higher Ki-67 index, presence of necrosis, and pleural infiltration (p < 0.05). No association was observed between high DLL3 expression and overall survival (OS) and disease-free survival (DFS) in high-grade NETs, whereas high DLL3 expression was associated with lower DFS in ACs (p = 0.01). In conclusion, our study demonstrated a high prevalence of DLL3 expression in high-grade lung NET patients and its association with aggressive clinicopathological features. These findings confirm that DLL3 could represent a useful biomarker for target therapy in high-grade tumors. Our results also suggest that the DLL3 expression could identify a subset of AC tumors with more aggressive behavior, thus providing the basis for new therapeutic options in this group of patients.

Tall cell percentage alone in PTC without aggressive features should not guide patients' clinical management

CONTEXT

Recent diagnostic criteria updates of the tall cell variant of papillary thyroid carcinoma (TCPTC) by the World Health Organization (WHO) have determined the inclusion of tumors with 30% to 49% of tall cells. However, the impact of tall cell percentage on papillary thyroid carcinoma (PTC) patients' prognosis is still debated.

OBJECTIVE

We aimed to evaluate whether tall cell percentage affects patient outcome in the absence of aggressive features.

METHODS

Rates of aggressive features, recurrence-free survival (RFS), and distant RFS (5-year median follow-up) were compared among tumors with less than 30%, 30% to 49% and at least 50% tall cells. We also evaluated the impact of the new tall cell cutoff on patient management.

RESULTS

Overall, 3092 tumors (15.7% of all PTCs) were collected: A total of 792 PTCs had less than 30%, 503 had 30% to 49%, and 1797 had 50% or more tall cell areas. With the new WHO definition, the number of TCPTCs increased by 28%. There were no differences in recurrence rates according to tall cell percentage. The coexistence of BRAF and TERT promoter mutations predicted a worse RFS. Considering the new definition of TCPTC, the level of risk according to the American Thyroid Association increased from low to intermediate in 4.2% of cases. However, the recurrence rate within this subgroup was comparable to low risk.

CONCLUSION

TCPTC and PTC with tall cell areas can be considered as a unique group with similar recurrence risk. However, whenever aggressive features are absent, tumors have a low risk of recurrence independently of tall cell percentage.

Biomarkers and Gene Signatures to Predict Durable Response to Pembrolizumab in Non-Small Cell Lung Cancer

Simple Summary

Not all patients with advanced or metastatic non-small cell lung cancer (NSCLC) respond to pembrolizumab, even if their tumor expresses PD-L1. This is a monocentric study aimed at identifying potential predictive biomarkers for pembrolizumab first-line treatment. Tumor microenvironment was characterized by gene expression analysis in 46 tumor samples from 25 NSCLC patients with and 21 without durable clinical benefit. As expected, patients achieving clinical benefit had a greater infiltration of immune cells. In particular, CD8 T-cell and NK cell scores were strongly associated with durable benefit. Single immune cell markers such as XCL1/2 showed a high performance in predicting durable response to pembrolizumab with an AUC of 0.85. In the same series PD-L1 expression levels had an AUC equal to 0.61. Identified predictive biomarkers can improve patients’ selection, thus optimizing treatment definition.

Abstract

Pembrolizumab has been approved as first-line treatment for advanced Non-small cell lung cancer (NSCLC) patients with tumors expressing PD-L1 and in the absence of other targetable alterations. However, not all patients that meet these criteria have a durable benefit. In this monocentric study, we aimed at refining the selection of patients based on the expression of immune genes. Forty-six consecutive advanced NSCLC patients treated with pembrolizumab in first-line setting were enrolled. The expression levels of 770 genes involved in the regulation of the immune system was analysed by the nanoString system. PD-L1 expression was evaluated by immunohistochemistry. Patients with durable clinical benefit had a greater infiltration of cytotoxic cells, exhausted CD8, B-cells, CD45, T-cells, CD8 T-cells and NK cells. Immune cell scores such as CD8 T-cell and NK cell were good predictors of durable response with an AUC of 0.82. Among the immune cell markers, XCL1/2 showed the better performance in predicting durable benefit to pembrolizumab, with an AUC of 0.85. Additionally, CD8A, CD8B and EOMES showed a high specificity (>0.86) in identifying patients with a good response to treatment. In the same series, PD-L1 expression levels had an AUC of 0.61. The characterization of tumor microenvironment, even with the use of single markers, can improve patients’ selection for pembrolizumab treatment.

Molecular Alterations in Relation to Histopathological Characteristics in a Large Series of Pediatric Papillary Thyroid Carcinoma from a Single Institution

Papillary thyroid carcinoma (PTC) presents distinct clinico-pathological and molecular differences in children compared with adult patients. Whether the presence of rearrangements or point mutations is associated with aggressive PTC clinical presentation is still controversial. In this study, PTCs diagnosed in patients aged less than 18 years were retrospectively searched from the institutional archive and tumor tissue was tested for point mutations in BRAF and RAS genes and for rearrangements in RET, NTRK1, NTRK3, ALK, PPARG, BRAF and THADA. A total of 163 PTCs were analyzed. Point mutations were found in 83 (51%) and gene fusions in 48 cases (30%). The most frequent alteration was the BRAFV600E mutation (36.8%), followed by NTRK3 fusion (11%), NRAS mutation (10.4%) and RET fusion (10.4%). Fusion-driven PTCs showed more frequently infiltrative growth, larger tumors, extrathyroidal extension and N1b disease. PTCs showing solid growth pattern were significantly enriched in gene fusions. This is one of the largest cohorts of pediatric PTCs. Fusion-driven tumors most frequently show aggressive pathological features; the search for rearrangements, especially in tumors with solid areas, could improve the characterization of pediatric PTCs and offer possible therapeutic options.

Multiple Resistance Mechanisms to Tyrosine Kinase Inhibitors in EGFR Mutated Lung Adenocarcinoma: A Case Report Harboring EGFR Mutations, MET Amplification, and Squamous Cell Transformation

Resistance to EGFR tyrosin kinase inhibitors (TKI) inevitably occurs. Here it is reported the case of a young patient affected by lung adenocarcinoma harboring the L858R EGFR sensitive mutation. The patient developed multiple TKI resistance mechanisms: T790M EGFR resistance mutation, detected only on tumor cell-free DNA, squamous cell transformation and MET amplification, both detected on a tumor re-biopsy. The co-occurrence of squamous cell transformation and de novo MET amplification is an extremely rare event, and this case confirms how dynamic and heterogeneous can be the temporal and spatial tumor evolution under treatment pressure.

Role of Prophylactic Central Compartment Lymph Node Dissection on the Outcome Of Patients With Papillary Thyroid Carcinoma and Synchronous Ipsilateral Cervical Lymph Node Metastases

OBJECTIVE

Prophylactic central compartment lymph node dissection (pCCND) results in a higher percentage of surgical-related complications. To date, no evidence of the impact of pCCND on the clinical outcome of papillary thyroid carcinoma (PTC) patients with synchronous ipsilateral cervical lymph node metastases has been reported.

METHODS

We evaluated all consecutive patients affected by PTC and synchronous ipsilateral cervical, but without evidence of central compartment, lymph node metastases. We selected 54 consecutive patients (group A) treated by total thyroidectomy, ipsilateral cervical lymph node dissection, and pCCND and 115 patients (group B) matched for sex, age at diagnosis, number and dimension of the metastatic lateral cervical lymph nodes, without pCCND. Clinical outcome after a median of 5 years and surgical-related complications were assessed.

RESULTS

The two groups were completely similar in terms of clinical features. Clinical outcomes showed a higher percentage of biochemical and indeterminate but not structural response in group B. Group B required significantly more radioiodine treatments, but no difference was shown in the need to repeat surgery for recurrences. Conversely, the prevalence of permanent hypoparathyroidism was significantly higher in group A (14.8%) than in group B (4.3%).

CONCLUSION

In PTC patients with synchronous ipsilateral cervical lymph node metastases, in absence of clinically evident lymph node metastases of the central compartment, performing pCCND does not improve the 5-year outcome in terms of structural disease, despite a greater number of ¹³¹I treatments. However, pCCND is severely affected by a higher percentage of permanent hypoparathyroidism, even in the hands of expert surgeons.

ABBREVIATIONS

IQR = interquartile range; pCCND = prophylactic central compartment lymph node dissection; PTC = papillary thyroid carcinoma; Tg = thyroglobulin; US = ultrasound.

The cortisol burden in elderly subjects with metabolic syndrome and its association with low-grade inflammation

BACKGROUND

Elderly people are exposed to an increased load of stressful events and neuro-hormonal stimulation is a key finding in metabolic syndrome and its related disorders.

AIMS

To determine the role of cortisol in elderly subjects, with or without metabolic syndrome (MetS), by means of a national multicentre observational study, AGICO (AGIng and Cortisol).

METHODS

From 2012 to 2017, the AGICO study enrolled n.339 subjects (aged > 65), after obtaining their informed consent. The investigators assessed a cardio-metabolic panel (including electrocardiogram, carotid ultrasonography and echocardiography), the presence of MetS (on Adult Treatment Panel III criteria), a neurological examination (including brain imaging), and cortisol activity (using a consecutive collection of diurnal and nocturnal urine).

RESULTS

In the patients presenting with MetS, the standardized diurnal and nocturnal cortisol excretion rates were 210.7 ± 145.5 and 173.7 ± 118.1 (mean ± standard deviation) μg/g creatinine/12 h; in those without MetS, the standardized diurnal and nocturnal cortisol excretion rates were 188.7 ± 92.7 and 144.1 ± 82.3 μg/g creatinine/12 h, respectively (nocturnal urinary cortisol in patients with MetS versus those without MetS p = 0.05, female patients with MetS vs female patients without MetS, p < 0.025). A significant positive correlation was found between the CRP levels and both the diurnal and nocturnal urinary cortisol levels with r = 0.187 (p < 0.025) and r = 0.411 (p < 0.00000001), respectively.

DISCUSSION

The elderly patients with MetS showed a trend towards increased standardized nocturnal cortisol excretions, with particular regard to the female subjects.

CONCLUSION

The positive correlation between cortisol excretion and low-grade inflammation suggests a common mechanism driving both hormonal and inflammatory changes.

Developing a tool that could reliably refute total thyroidectomy for solitary Bethesda IV thyroid nodules

PURPOSE

To assess the reliability of a simple, accessible, cost-effective rule-out tool, for use in triaging patients with Bethesda IV nodules to appropriate surgery.

METHODS

The diagnostic tool was assembled by combining the negativity for suspicious ultrasound features (irregular margins, microcalcification, and a taller-than-wide orientation), and mutational marker negativity (BRAF and NRAS). The tool, (US^-/mutation^-), was tested on 167 patients with solitary Bethesda IV nodules. The primary outcome was its negative predictive value (NPV) for lesions requiring total thyroidectomy (TT). The impact of mutational marker negativity, as part of the tool, was evaluated by comparing the NPV of (US^-/mutation^-) to that of (US^-/mutation⁺).

RESULTS

10 out of 167 lesions were positive for a mutational marker. These underwent TT, and only 2/10 (20%) were benign, on final histology. In 6/8 malignant lesions, TT was concordant with current clinical guidelines. 157 patients comprised the negative study cohort, for both mutational markers and suspicious US features. These underwent thyroid lobectomy, and 17 cases resulted in malignancy, only 8 of which required completion thyroidectomy. Accordingly, the NPV of (US^-/mutation^-) for malignancy was 89% (140/157), and 95% (149/157) for malignancy requiring TT. However, the NPV of (US^-/mutation⁺) was 20% for malignancy, and 40% for malignancy requiring TT. These differences were statistically significant (89% vs. 20%; p < 0.0001, and 95% vs. 40%; p < 0.0001).

CONCLUSION

US^-/mutation^- is a reliable rule-out tool, with sufficient diagnostic accuracy to spare patients, with Bethesda IV nodules, an overly radical TT.

Differential Diagnosis of Malignant Pleural Mesothelioma on Cytology: A Gene Expression Panel versus BRCA1-Associated Protein 1 and p16 Tests

Pleural effusions are among the first clinical manifestations of malignant pleural mesothelioma (MPM) and often constitute the only available material for diagnosis. Although an MPM diagnosis can be reliable on cytology, the reported sensitivity is low (30% to 75%). Particularly, it can be hard to discriminate epithelioid MPM, the most common histotype, from reactive mesothelial hyperplasia (MH). Currently, BRCA1-associated protein 1 (BAP1) and CDKN2A (p16), evaluated by immunohistochemistry and fluorescent in situ hybridization, respectively, are the most valuable markers to discriminate MPM and MH. Both markers have a high specificity, but their sensitivity is not always satisfying, even when used together. We have recently developed a 117-gene expression panel, based on Nanostring technology, able to differentiate epithelioid MPM from MH pleural tissues better than BAP1 and p16. Herein, we evaluated the efficacy of the same panel on an independent retrospective cohort of 23 MPM and 11 MH pleural effusions (cell blocks and smears). The overall sensitivity and specificity of the panel were equal to 0.9565 and 1, respectively. Moreover, the panel performance was compared with BAP1 and p16 on 25 cell blocks. Sensitivity levels of gene panel, BAP1 alone, p16 alone, and BAP1 plus p16 were 1, 0.5882, 0.4706, and 0.7647, respectively. Specificity was always 1. Although further validation is needed, this gene panel could really facilitate patients' management, allowing a definitive MPM diagnosis directly on pleural effusions.

Noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP): a new entity

Since its first official definition in 2016, the new histo-pathological entity of noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) has attracted much interest among "thyroidologists" worldwide. This is a subset of encapsulated and noninvasive follicular variant papillary thyroid cancer, whose introduction had the intent of de-escalating treatment given its very low malignant potential, approaching to that of follicular adenomas. Many researchers focused on the possibility of preoperatively identifying NIFTP, and investigated their cyto-morphological and molecular characteristics; other ones explored histological and clinical-pathological NIFTP features. Although the majority of published studies confirmed that NIFTP are indolent lesions, some papers did question their low-risk nature. In this brief review, the main aspects of histology, cytology and molecular pathology of NIFTP are discussed based on the current literature.

A gene-expression-based test can outperform bap1 and p16 analyses in the differential diagnosis of pleural mesothelial proliferations

The demonstration of tissue invasion by histology is an essential criterion for the differential diagnosis of benign and malignant mesothelial proliferations. When tissue invasion cannot be identified, the use of ancillary tests is sometimes necessary. Among investigated markers, the loss of BRCA1 associated protein 1 (BAP1) protein expression and the homozygous deletion of p16 have shown 100% specificity in separating benign and malignant mesothelial lesions. However, beyond the excellent specificity of these two markers, their low sensitivity limits their clinical utility. In this context, a previous study developed and tested a novel tool for use in the differential diagnosis of malignant pleural mesothelioma (MPM) using the NanoString System and a classification algorithm. In the current study, the performance of gene classifiers were compared using BAP1 and p16 testing. p16 FISH and BAP1 immunohistochemistry were performed on the same series of 34 epithelioid MPM and 20 benign pleural lesions, which were previously analyzed by the system. The diagnostic performance of p16, BAP1 and our classification models were compared using ROC analysis. It was observed that BAP1 loss and p16 deletion were highly specific for MPM, since they were not detected in benign lesions. However, their AUC values were not completely satisfying (BAP1: 0.8235; p16: 0.7647) particularly due to their low sensitivities. As expected, combining BAP1 and p16 tests increased the diagnostic sensitivity, thus improving the AUC (0.8824). In the same series of cases, our MPM tool outperformed BAP1 and p16 tests using the 22 and 40-gene classification models (AUC 22-gene model: 0.9996; AUC 40-gene model: 0.9990). In conclusion, the present gene-expression-based classification exhibited great potential and further validation is required to support these findings in a prospective fashion, in order to provide a solid alternative for pleural proliferation diagnosis.

Digital Gene Expression Analysis on Cytology Smears Can Rule Out Malignancy in Follicular-Patterned Thyroid Tumors

Patients with indeterminate thyroid nodules (Bethesda III and IV) are often treated with diagnostic lobectomy, which in most cases represents an overtreatment. A reliable rule-out molecular test could spare patients unnecessary surgery. Stained smears of 88 indeterminate thyroid nodules with histologic diagnosis of follicular-patterned tumors were selected: 34 follicular adenomas (FAs), 34 follicular variant papillary thyroid carcinomas (FVPTCs), and 20 noninvasive follicular neoplasms with papillary-like nuclear features (NIFTPs). The expression level of 126 genes was measured by digital counting. Mutation testing was performed for the main gene mutations and fusions. Performance of gene expression and mutation tests was calculated by receiver operating characteristic analysis. The gene expression model showed an area under the curve (AUC) of 88%, with 91% negative predictive value in FAs and FVPTCs only. Part of NIFTPs was labeled as benign, and part was labeled as malignant; thus, the classifier performance worsened. Two FAs (5.9%), eight NIFTPs (40%), and 22 FVPTCs (64.7%) were mutation positive. Mutation testing AUC was 79% in FAs and FVPTCs, and decreased by including NIFTPs. This gene expression-based test was feasible in thyroid-stained smears, showed higher AUC than mutation test, and had a high negative predictive value-making it a good candidate as a rule-out test for indeterminate thyroid cytology. NIFTPs have a heterogeneous phenotype, and their preoperative diagnosis requires further investigation.

Myofibroblast Gene Expression Profile after Tooth Extraction in the Rabbit

After tooth extraction, the alveolar bone tends to shrink in volume, especially on the vestibular side. The role of myofibroblasts in bone remodeling has not been sufficiently investigated. The aim of the present study was to explore the gene expression related to myofibroblasts presence and activity during a 90-day healing period after tooth extraction. The study included 36 rabbits, and a single tooth extraction was performed on each rabbit. The extractive sockets were randomly distributed to natural healing or to scarification of the wound. The sacrifices were staggered in such a manner that animals contributed with sockets representing 2, 7, 15, 30, 60, and 90 days of healing. Nanostring technology was used to evaluate the expression of a wide panel consisting in 148 genes related to the activation, induction, and suppression of myofibroblasts, socket microenvironment, and autophagy. We found that the expression profile of this custom panel was time-related. The post-extractive socket was subjected to significant gene expression changes after 15 days: the genes involved in the induction of myofibroblasts were up-regulated in the first 15-day period and down-regulated during the rest of the follow-up. The study suggested that myofibroblasts play a major role in the immediate 15-day period following tooth extraction.

Association between DNA methylation profile and malignancy in follicular-patterned thyroid neoplasms

Molecular differentiation between benign (follicular thyroid adenoma, FTA) and malignant (follicular thyroid carcinoma, FTC) thyroid neoplasms is challenging. Here, we explored the genome-wide DNA methylation profile of FTA (n.10) and FTC (n.11) compared to normal thyroid (NT) (n.7) tissues. FTC featured 3,564 differentially-methylated CpGs (DMCpG), most (84%) of them hypermethylated, with respect to normal controls. At the principal component analysis (PCA), the methylation profile of FTA occupied an intermediate position between FTC and normal tissue. A large fraction (n. 2,385) of FTC-associated DMCpG were related (intragenic or within 1500 bp from the transcription start site) to annotated genes (n. 1,786). FTC-hypermethylated genes were enriched for targets of the Polycomb transcriptional repressor complex and the specific histone H3 marks (H3K4me2/me3-H3K27me3) found in chromatin domains known as "bivalent". Transcriptome profiling by RNAseq showed that 7.9% of the DMCpGs-associated genes were differentially expressed in FTC compared to NT, suggesting that altered DNA methylation may contribute to their altered expression. Overall, this study suggests that perturbed DNA methylation, in particular hypermethylation, is a component of the molecular mechanisms leading to the formation of FTC and that DNA methylation profiling may help differentiating FTCs from their benign counterpart.

The mutational analysis in the diagnostic work-up of thyroid nodules: the real impact in a center with large experience in thyroid cytopathology

PURPOSE

Fine-needle aspiration (FNA) cytology is a mainstay in the evaluation of thyroid nodules, but fails to reach reliable results in 25-30% of cases. The role of molecular markers in helping clinical decisions has been investigated for the last years, but their clinical usefulness is still unsettled.

METHODS

Mutation analysis of BRAF, RAS genes and TERT promoter was performed in a series of 617 consecutive cytological specimens undergoing FNA.

RESULTS

The 617 nodules had the following cytological diagnosis: non diagnostic 22 (3.6%), benign 425 (68.9%), indeterminate 114 (18.5%), suspicious 11 (1.8%) and malignant 45 (7.3%). BRAF mutations were found in 31 cases (5.0%), all but two in suspicious and malignant nodules. RAS mutations were detected in 47 samples (7.6%): 25 benign (5.9%) and 19 indeterminate nodules (16.7%). TERT promoter mutation alone was detected in three samples. Histological outcome was available for 167 nodules, 81 of which proved malignant: all the 48 with suspicious or malignant cytology; 25 out of 56 (44.6%) with indeterminate and 8 out of 57 (14%) with benign cytology. BRAF mutations were associated with worse tumors pathological features. The presence of RAS mutations was indicative of follicular-patterned malignancies in 5 out of 8 benign nodules and 9 out of 11 indeterminate nodules.

CONCLUSIONS

Our study established mutational rates for BRAF and RAS genes in a large series of FNA specimens. BRAF mutations were confirmed as highly specific but not able to improve cytological diagnosis, while RAS testing proved effective in assessing malignancy in nodules with indeterminate and benign cytology.

Patients with Indeterminate Thyroid Nodules at Cytology and Cancer at Histology Have a More Favorable Outcome Compared with Patients with Suspicious or Malignant Cytology

BACKGROUND

The outcomes of patients with thyroid cancer proven by histology in patients in whom cytology was Thy 3 (indeterminate; Thy 3 patients in this study) based on the Italian consensus classification compared with those in whom cytology was Thy 4 (suspicious for malignancy) or Thy 5 (indicative for malignancy) (Thy 4-5 patients here) remains unclear.

OBJECTIVE

To analyze the outcome of 371 Thy 3 patients versus 269 Thy 4-5 patients homogeneously treated with total thyroidectomy and ¹³¹I activity.

RESULTS

T1 stage was observed in 46.0% of Thy 3 and in 38.8% of Thy 4-5 patients (p = 0.02), N0 in 95.9% of Thy 3 and in 75.5% of Thy 4-5 patients (p < 0.0001). 35/261 (9.6%) Thy 3 and 85/269 (31.5%) Thy 4-5 patients required >30 mCi of ¹³¹I (p < 0.0001). 359/371 (96.8%) Thy 3 and 232/269 (86.2%) Thy 4-5 patients were free of disease at the end of follow-up (p < 0.001). The time required to obtain 50% of patients in remission was 2 years in Thy 3 and 4 years in Thy 4-5 patients (p < 0.001). The most common histological type was the follicular variant of papillary thyroid carcinoma (FV-PTC) in Thy 3 patients (239/371, 64.4%) and the classic variant in Thy 4-5 patients (185/269; 68.8%). The FV-PTC had better prognostic features compared with the other PTC variants: T1 stage was observed in 133/277 (48.0%) FV-PTC patients and in 146/363 (40.0%) patients with the other variants (p < 0.001), N0 was present in 265/277 (96.0%) FV-PTC and in 290/363 (79.8%) patients with the other variants (p < 0.001). Overall, 267/277 FV-PTC patients (96.4%) and 324/363 patients (89.0%) with the other variants were free of disease (p < 0.0008) at the end of follow-up, and the time required to obtain 50% of patients in remission was 2 years in FV-PTC and 4.0 years in the other variants (p < 0.001).

CONCLUSION

Patients with Thy 3 cytology have better outcomes of thyroid cancer compared with patients with Thy 4 or Thy 5 cytology, and indeterminate cytology is commonly associated with the less aggressive FV-PTC.

Hypovitaminosis D: comparison between patients with hip fracture and patients with vertebral fractures

This study analyses the difference in 25OH-vitamin D values between two groups of patients both affected by severe osteoporosis with fragility fractures, but one group has vertebral fractures and the other one has hip fractures. Patients with hip fractures have vitamin D values lower than patients with vertebral fractures.

INTRODUCTION

The purpose of this study was to evaluate 25OHD levels in patients with fragility vertebral fractures (VF) and hip fractures (HF) and make a comparison between the groups.

METHODS

In the first group were enrolled ambulatory patients with 3 or more moderate to severe VF; in the second group were enrolled patients hospitalized in the Department of Orthogeriatrics undergoing surgery for HF. For all patients, we collected values of 25OHD and PTH. The group of patients with VF was further subdivided into pre-existing VF or recent VF treated within 30 days with vertebroplasty.

RESULTS

The sample consists of 180 subjects divided into two groups: 90 with VF and 90 with HF. The average value of 25OHD in the total sample was 13.2 ± 9.6 ng/ml, Vitamin D was significantly lower in the HF group than the VF group (p < 0.001)(VF 18.6 ± 9.7 ng/ml, HF 7.9 ± 5.7 ng/ml). The mean PTH value in the total sample was 67.5 ± 54.9 pg/ml and PTH was significantly higher in the HF group compared to the group with VF (p < 0.001) (VF 55.6 ± 27.2 pg/ml, HF 78.7 ± 70.2 pg/ml). The mean 25OHD value in the recent VF group is 16.0 ± 6.6 ng/ml while in the pre-existing VF group is 19.5 ± 10.4 ng/ml with a statistically significant difference (p < 0.001).

CONCLUSIONS

Patients of the same age with severe osteoporosis have a lower 25OHD value when the fracture occur at the hip and is recent, probably this is due to the inflammation caused by fracture and/or surgical intervention.

Malignant pleural mesothelioma and mesothelial hyperplasia: A new molecular tool for the differential diagnosis

Malignant pleural mesothelioma (MPM) is a rare asbestos related cancer, aggressive and unresponsive to therapies. Histological examination of pleural lesions is the gold standard of MPM diagnosis, although it is sometimes hard to discriminate the epithelioid type of MPM from benign mesothelial hyperplasia (MH).This work aims to define a new molecular tool for the differential diagnosis of MPM, using the expression profile of 117 genes deregulated in this tumour.The gene expression analysis was performed by nanoString System on tumour tissues from 36 epithelioid MPM and 17 MH patients, and on 14 mesothelial pleural samples analysed in a blind way. Data analysis included raw nanoString data normalization, unsupervised cluster analysis by Pearson correlation, non-parametric Mann Whitney U-test and molecular classification by the Uncorrelated Shrunken Centroid (USC) Algorithm.The Mann-Whitney U-test found 35 genes upregulated and 31 downregulated in MPM. The unsupervised cluster analysis revealed two clusters, one composed only of MPM and one only of MH samples, thus revealing class-specific gene profiles. The Uncorrelated Shrunken Centroid algorithm identified two classifiers, one including 22 genes and the other 40 genes, able to properly classify all the samples as benign or malignant using gene expression data; both classifiers were also able to correctly determine, in a blind analysis, the diagnostic categories of all the 14 unknown samples.In conclusion we delineated a diagnostic tool combining molecular data (gene expression) and computational analysis (USC algorithm), which can be applied in the clinical practice for the differential diagnosis of MPM.

Analysis of Fusion Genes by NanoString System: A Role in Lung Cytology?

CONTEXT

- Patients with non-small cell lung cancer harboring ALK receptor tyrosine kinase ( ALK), ROS proto-oncogene 1 ( ROS1), and ret proto-oncogene ( RET) gene rearrangements can benefit from specific kinase inhibitors. Detection of fusion genes is critical for determining the best treatment. Assessing rearrangements in non-small cell lung cancer remains challenging, particularly for lung cytology.

OBJECTIVE

- To examine the possible application of the multiplex, transcript-based NanoString system (NanoString Technologies, Seattle, Washington) in the evaluation of fusion genes in lung adenocarcinoma samples.

DATA SOURCES

- This study is a narrative literature review. Studies about NanoString, gene fusions, and lung adenocarcinoma were collected from PubMed (National Center for Biotechnology Information, Bethesda, Maryland). We found 7 articles about the application of the NanoString system to detect fusion genes on formalin-fixed, paraffin-embedded tumor tissues and one article evaluating the adequacy of lung cytologic specimens for NanoString gene expression analysis.

CONCLUSIONS

- To maximize the yield of molecular tests on small lung biopsies, the NanoString nCounter system has been suggested to detect fusion genes. NanoString fusion gene assays have been successfully applied on formalin-fixed, paraffin-embedded tissues. Although there are only a few studies available, the application of NanoString assays may also be feasible in lung cytology. According to available data, the NanoString system could strengthen the routine molecular characterization of lung adenocarcinoma.

TERT promoter mutations and their correlation with BRAF and RAS mutations in a consecutive cohort of 145 thyroid cancer cases

Papillary thyroid carcinoma (PTC) is the most common type of endocrine malignancy and accounts for ~80% of thyroid carcinomas in adults and 90% in children. Risk stratification is important for identifying patients at higher risk and, for this reason, recent advances in molecular genetics of thyroid cancer can be applied to provide novel biomarkers useful in understanding tumor behavior. B-Raf proto-oncogene, serine/threonine kinase (BRAF) and rat sarcoma (RAS) mutations have been widely studied and appear to have an important role in thyroid tumorigenesis. Somatic telomerase reverse transcriptase (TERT) promoter mutations have been recently identified in several types of malignant tumors, including thyroid neoplasia; however, the actual role of TERT mutations in thyroid tumorigenesis is still under debate. In the present study, the mutational status of BRAF, RAS and TERT was analyzed in order to elucidate the roles of these genes in thyroid tumorigenesis. The TERT mutational analysis was also correlated with an immunohistochemical study of TERT protein expression. According to the literature, our data provide evidence of the BRAF and RAS roles in thyroid tumorigenesis, supporting an association between BRAF (V600E) mutations and the more aggressive clinical and pathological features of thyroid tumors. By contrast, TERT mutations were not significantly associated with any clinical parameters; therefore, its role in initial tumorigenesis should be further investigated.

Presence of cancer cells in gastric lavage of gastric cancer patients as an indicator of advanced disease, predictor of tumour aggressive phenotype and independent prognostic factor for poor survival: The endoluminal metastatic pathway of gastric cancer and GL0/GL1 classification

OBJECTIVE

As of 2017, the pathobiology of gastric cancer (GC) is far from fully understood; consequently, new methods of basic and advanced research have been proposed and tested. The presence (GL1) vs absence (GL0) of malignant cells exfoliated in gastric lavage (GL) of GC patients was formerly evaluated with diagnostic intent but not for staging or prognostic assessment. We investigated this hitherto unreported application of cytopathology.

METHODS

GL was preoperatively and prospectively collected from 80 GC patients and cytologically analysed. The results were compared with the classic clinicopathological features of GC and related to survival. The prognostic value of GL1 was assessed through univariate and multivariate analyses.

RESULTS

GL1 was detected in 36 samples (45%) and correlated with advanced tumour depth (T3-T4), lymphatic metastasis (N+), distant metastasis (M1) and lymphovascular invasion (LVI1; P=.0317, .0024, .003 and .0028, respectively). Overall survival (OS) was significantly shorter for GL1 (23 months) vs GL0 patients (42 months; P=.005) and GL1 vs GL0 T1 subjects (12.6 vs 47.8 months, P=.0029). Univariate analysis revealed that GL1, N+, M1, LVI1 and advanced stage were significantly associated with OS. Multivariate analysis assessed GL1 as the only independent prognostic factor for worse OS and progression-free survival (P=.0013 and .0107).

CONCLUSIONS

In the present study, GL1 was correlated with advanced disease, aggressive tumour behaviour and poor prognosis. Although additional studies are needed to confirm these findings, the GL0/GL1 classification can be applied to GC patients to achieve higher accuracy in staging, prognostic stratification and treatment selection.

Squamous cell transformation and EGFR T790M mutation as acquired resistance mechanisms in a patient with lung adenocarcinoma treated with a tyrosine kinase inhibitor: A case report

The present case report describes the infrequent coexistence of squamous cell transformation and the epidermal growth factor receptor (EGFR) T790M mutation as resistance mechanisms to first line treatment with tyrosine kinase inhibitors. The patient was a 44-year-old female, diagnosed with a primitive advanced lung adenocarcinoma with bone metastases. The tumor was positive for the EGFR exon 19 deletion, therefore the patient was treated with afatinib (40 mg/day, orally) and radiotherapy for bone lesions. After 16 months, the patient developed resistance. Cytological examination of the pleural effusion confirmed an adenocarcinoma positive for the EGFR exon 19 deletion and the T790M mutation within exon 20, while a biopsy from the upper left bronchus revealed a keratinizing squamous cell carcinoma positive for the EGFR exon 19 deletion. In addition, the EGFR mutations were concomitantly detected in circulating cell-free tumour DNA. Due to the presence of the T790M mutation, the patient underwent osimertinib therapy (80 mg/day, orally), which resulted in a partial tumour regression at the 2-month follow-up, whereas the squamous lesions were treated with radiotherapy. The adenocarcinoma and squamous carcinoma components may share the same origin, according to the presence of the EGFR exon 19 deletion in both lesions. More accurate characterization of resistance mechanisms may lead to the development of improved treatment regimens.

Sodium-glucose co-transporter (SGLT)2 and SGLT1 renal expression in patients with type 2 diabetes

AIM

To quantify the expression of sodium-glucose co-transporter (SGLT)2 and SGLT1, their cognate basolateral transporters, GLUT2 and GLUT1, and the transcriptional regulator of SGLTs in renal tissue obtained from people with T2DM and a group of well-matched people without diabetes.

METHODS

We measured SGLT2 and SGLT1 expression in unaffected renal tissue from 19 people with T2DM and 20 people without diabetes, matched for age and estimated glomerular filtration rate (controls), undergoing unilateral nephrectomy. Expression of SGLT2 and SGLT1, as well as that of GLUT2 and GLUT1, was quantified using real-time and digital PCR; an affinity-purified antibody against human SGLT2 was used to localize SGLT2 by immunohistochemistry.

RESULTS

SGLT2 expression was higher in control than T2DM tissue (median [interquartile range] target/β-actin 1.62 [2.02] vs 0.67 [0.61]; P < .0001), and SGLT1 trended in the same direction (0.98 [1.19] vs 0.44 [0.48]; P = .08). Immunohistochemistry clearly localized SGLT2 to the tubular brush-border membranes, and was semi-quantitatively stronger in control than T2DM tissue (5.0 [1.0] vs 4.0 [1.0] score units; P = .043). GLUT2 (control vs T2DM: 1.00 [0.69] vs 0.49 [0.36]) and GLUT1 expression (control vs T2DM: 0.86 [0.73] vs 0.35 [0.30]; P = .0007 for both) were closely correlated with those of the respective SGLT partner. Hypoxia-inducible factor 1α, more abundant in control than T2DM tissue, might be a transcription factor involved in the modulation of SGLT2 expression.

CONCLUSIONS

In whole renal tissue, expressions of SGLT2/GLUT2 and SGLT1/GLUT1 are coupled and slightly lower in typical people with T2DM as compared with well-matched people without diabetes.

Invasive anisakiasis by the parasite Anisakis pegreffii (Nematoda: Anisakidae): diagnosis by real-time PCR hydrolysis probe system and immunoblotting assay

Background

Anisakiasis is a fish-borne zoonosis caused by Anisakis spp. larvae. One challenging issue in the diagnosis of anisakiasis is the molecular detection of the etiological agent even at very low quantity, such as in gastric or intestinal biopsy and granulomas. Aims of this study were: 1) to identify three new cases of invasive anisakiasis, by a species-specific Real-time PCR probe assay; 2) to detect immune response of the patients against the pathogen.

Methods

Parasite DNA was extracted from parasites removed in the three patients. The identification of larvae removed at gastric and intestinal level from two patients was first obtained by sequence analysis of mtDNA cox2 and EF1 α-1 of nDNA genes. This was not possible in the third patient, because of the very low DNA quantity obtained from a single one histological section of a surgically removed granuloma. Real-time PCR species-specific hydrolysis probe system, based on mtDNA cox2 gene, was performed on parasites tissue of the three cases. IgE, IgG₄ and IgG immune response against antigens A. pegreffii by Immunoblotting assay was also studied.

Results

According to the mtDNA cox2 and the EF1 α − 1 nDNA sequence analysis, the larvae from stomach and intestine of two patients were assigned to A. pegreffii. The Real-time PCR primers/probe system, showed a fluorescent signal at 510 nm for A. pegreffii, in all the three cases.

In Immunoblotting assay, patient CC1 showed IgE, IgG₄ reactivity against Ani s 13-like and Ani s 7-like; patient CC2 revealed only IgG reactivity against Ani s 13-like and Ani s 7-like; while, the third patient showed IgE and IgG reactivity against Ani s 13-like, Ani s 7-like and Ani s 1-like.

Conclusion

The Real-time PCR assay, a more sensitive method than direct DNA sequencing for the accurate and rapid identification of etiological agent of human anisakiasis, was successfully assessed for the first time. The study also highlights the importance to use both molecular and immunological tools in the diagnosis of human anisakiasis, in order to increase our knowledge about the pathological findings and immune response related to the infection by zoonotic species of the genus Anisakis.

MET exon 14 mutations in advanced lung adenocarcinoma: Frequency and coexisting alterations

e20656

Background: In lung cancer the evaluation of MET, a tyrosine kinase receptor involved in tumor growth and invasiveness, for copy number amplification and point mutations is relevant for prognosis and therapy. In lung adenocarcinoma (ADC) MET amplification is observed in 1-2% and MET mutations in 3-4% of cases. Mutations mainly occur in exon 14 (ex14), which encodes for the juxtamembrane negative regulatory domain, including splice site alterations and missense mutations within the exon.Commonly, MET ex14 alterations, in particular splice site ones, are mutually exclusive with other driver mutations, but co-occurrence with MET and MDM2 amplification and KRAS mutations was described. We evaluated METex14 mutation frequency and coexistence with additional driver alterations in a prospective cohort of Italian ADC patients. Methods: 315 ADC patients were tested (January-December 2016) for MET ex14 alterations by Sanger Sequencing on formalin-fixed paraffin-embedded tissues and cytological smears (tumor cells > 40%). MET positive cases were screened also for other oncogenes, among which KRAS, BRAF and PIK3CA, using a MALDI-TOF platform, and for ROS1 translocations and MET amplification by FISH. Results: 16 patients (5%) were MET positive: 7 splice site mutations (43%) and 9 (57%) other alterations within ex14. Among splice site mutations 1 co-occurred with ROS1 translocation and 1 with MET amplification. Among other mutations we found 5 T1010I missense mutations: 3 co-occurring with G12D/G13C/Q61H KRAS, 1 with G469A BRAF and 1 with a MET intron 13 point mutation; 2 R988C mutations: 1 with G13C KRAS and 1 with G13C KRAS plus ROS1 translocation; 1 P1026S mutation and 1 frameshift deletion (p.A991del;R992fs*999), both with G12C KRAS. Conclusions: Splice site mutations cause MET activation by exon skipping and increase sensitivity to tyrosine-kinase inhibitors, whereas how other ex14 mutations affect MET function is not fully understood. In our cohort we found a high rate of METex14 mutations together with alterations in other oncogenes, mostly KRAS. The interaction of MET with cancer signaling pathways deserve further investigation in order to better define the role of ex14 mutations in the context of target therapy.