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The pioneering design of chimeric antigen receptor (CAR) T-cell therapy demonstrated the potential of reprogramming the immune system. Nonetheless, T-cell exhaustion, toxicity, and suppressive microenvironments limit their efficacy in solid tumors. We previously characterized a subset of tumor-infiltrating CD4+ T cells expressing the FcγRI receptor. Herein, we detail engineering of a receptor, based on the FcγRI structure, allowing T cells to target tumor cells using antibody intermediates. These T cells showed effective and specific cytotoxicity only when an appropriate antibody was added. Only target-bound antibodies activated these cells, while free antibodies were internalized without activation. Their cytotoxic activity was correlated to target protein density, therefore targeting tumor cells with high antigen density while sparing normal cells with low or no expression. This activation mechanism prevented premature exhaustion. Furthermore, during antibody-dependent cytotoxicity these cells secreted attenuated cytokine levels compared with CAR T cells, thereby enhancing their safety profile. These cells eradicated established melanomas, infiltrated the tumor microenvironment, and facilitated host immune cell recruitment in immunocompetent mice. In NOD/SCID gamma mice the cells infiltrate, persist, and eradicate tumors. As opposed to CAR T-cell therapies, which require changing the receptor across different types of cancer, our engineered T cells remain the same across tumor types, while only the injected antibody changes. Overall, we generated a highly flexible T-cell therapy capable of binding a wide range of tumor cells with high affinity, while preserving the cytotoxic specificity only to cells expressing high density of tumor-associated antigens and using a single manufacturing process.

Background: Telomerase (human telomerase reverse transcriptase (hTERT) is considered a hallmark of cancer, being active in cancer cells but repressed in human somatic cells. As such, it has the potential to serve as a valid cancer biomarker. Exosomal hTERT mRNA can be detected in the serum of patients with solid malignancies but not in healthy individuals. We sought to evaluate the feasibility of measuring serum exosomal hTERT transcripts levels in patients with lung cancer. Methods: A prospective analysis of exosomal hTERT mRNA levels was determined in serum-derived exosomes from 76 patients with stage III–IV lung cancer (11 SCLC and 65 NSCLC). An hTERT level above RQ = 1.2 was considered “detectable” according to a previous receiver operating characteristic curve (ROC) curve. Sequential measurements were obtained in 33 patients. Demographic and clinical data were collected retrospectively from patients’ charts. Data on response to systemic therapy (chemotherapy, immunotherapy, and tyrosine kinase inhibitors) were collected by the treating physicians. Results: hTERT was detected in 53% (40/76) of patients with lung cancer (89% of SCLC and 46% of NSLCC). The mean hTERT levels were 3.7 in all 76 patients, 5.87 in SCLC patients, and 3.62 in NSCLC patients. In total, 25 of 43 patients with sequential measurements had detectable levels of hTERT. The sequential exosomal hTERT mRNA levels reflected the clinical course in 23 of them. Decreases in hTERT levels were detected in 17 and 5 patients with partial and complete response, respectively. Eleven patients with a progressive disease had an increase in the level of exosomal hTERT, and seven with stable disease presented increases in its exosomal levels. Another patient who progressed on the first line of treatment and had a partial response to the second line of treatment exhibited an increase in exosomal hTERT mRNA levels during the progression and a decrease during the response. Conclusions: Exosomal hTERT mRNA levels are elevated in over half of patients with lung cancer. The potential association between hTERT levels and response to therapy suggests its utility as a promising cancer biomarker for response to therapy. This issue should be further explored in future studies.

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Background: Primary cutaneous B-cell lymphoma (PCBCL) classically presents with papules, plaques, and nodules/tumors. Previous reports of PCBCL manifesting with macular lesions are scarce and focused on primary cutaneous follicle-center cell lymphoma (PCFCL). Objectives: The objective of this study was to report our experience with PCBCL presenting with erythematous macules. Methods: Patients with low-grade PCBCL manifesting with erythematous patches, diagnosed and managed between January 2000 through December 2019 at 2 tertiary cutaneous-lymphoma outpatient clinics, were included. Clinical data were retrospectively collected, and biopsy specimens of the macules, and if present of the typical nodular/tumoral lesions, were reviewed. Results: There were 14 patients, aged 16–67 years, 8 had PCFCL and 6 marginal zone lymphoma (PCMZL). All had 1–15 cm erythematous macules, mimicking: interstitial granuloma annulare/vascular tumors/early-stage folliculotropic mycosis fungoides, or presenting with figurate erythema or livedo reticularis-like/net-like pattern. In 3 patients, macules were the presenting lesions, in 2 as the sole manifestation, whereas in 12 patients, typical PCBCL lesions were observed during disease course. The macules showed in all, superficial and deep perivascular infiltrates, and in most, periadnexal infiltrates. Micronodules were observed in 11 specimens, with nodular infiltrates also observed in 4. B cells comprised the majority of the lymphocytes in only 4. Seven of 11 cases tested showed immunoglobulin heavy chain monoclonality. Conclusions: PCMZL and PCFCL may manifest with erythematous macules. Physicians should be aware of this unusual manifestation of low-grade PCBCL, which may represent a clinicopathological diagnostic pitfall.

Objective We employed a multidisciplinary approach incorporating theoretical ideas, clinical experience, psychology, physiology, traditional Chinese medicine (CM), modern practice of CM, and oncology to explore the effect of patients’ repression of negative emotions and traumatic events on breast cancer (BC) pathogenesis. Methods BC female patients, older than 18 years of age, with available pathology reports who were treated at Rabin Medical Center were recruited. All participants completed questionnaires regarding medical history, behavioral tendencies, negative emotions, trauma, symptoms, and pathology (from a CM perspective). Data on tumor characteristics were collected from the pathology reports. The associations were examined using hierarchical binary logistic regressions. Results A total of 155 BC patients were enrolled. The median age was 52 years, with a range of 26–79; 95% were mothers; 28% had estrogen receptor (ER)-negative BC, 52% had progesterone receptor (PR)-negative BC, 48% had human epidermal growth factor receptor 2-negative BC, and antigen Ki-67 ≥ 20% was reported for 52% of tumors. Statistically significant associations were found between the emotional markers (sense of motherhood failure, and lack of self-fulfillment), avoidance behavior, and physical symptoms that are related to emotional repression based on CM. Significant associations were also found between variables associated with physical symptoms of emotional repression, which involves the production and accumulation of non-substantial phlegm (i.e., “high-lipid Qi-like microscopic phlegm”), avoidance behavior which unconsciously uses “high-lipid Qi-like microscopic phlegm” in order to achieve emotional repression, and tumor parameters including tumor grade, PR status, and Ki-67. Patients with higher levels of “high-lipid Qi-like microscopic phlegm” were more likely to have tumors with worse prognosis (PR-negative, higher grade, and higher Ki-67). Conclusion We demonstrated a relationship between emotional parameters, behavioral tendencies, CM parameters, and oncologic parameters in BC. Additional research is warranted to explore these associations and their relevance to clinical practice.

The recent success of checkpoint blockade therapies has established immunotherapy as one of the most promising treatments for melanoma. Nonetheless, a complete curative response following immunotherapy is observed only in a fraction of patients. To identify what factors limit the efficacy of immunotherapies, we established mouse models that cease to respond to immunotherapies once their tumors exceed a certain stage. Analysis of the immune systems of the organisms revealed that the numbers of tumor-infiltrating dendritic cells (TIDC) drastically decreased with time. Further, in contrast to the current paradigm, once melanoma was established, TIDC did not migrate into sentinel lymph nodes. Instead, they underwent local cell death due to excessive phagocytosis of lysosomes. Importantly, TIDC were required to license the cytotoxic activity of tumor CD8+ T cells, and in their absence, T cells did not lyse melanoma cells. Our results offer a paradigm shift regarding the role of TIDC and a framework to increase the efficacy of immunotherapies.Significance:This work redefines the role of monocyte-derived dendritic cells in melanoma and provides a novel strategy to increase the efficacy of T-cell–based immunotherapies in nonresponding individuals.

Proteins associated with myeloid dendritic cells positively correlate with improved survival of melanoma patients

Tumor-infiltrating dendritic cells promote, in a contact-dependant manner, secretion of lytic granules by CD8+ T cells.

Melanoma tumor cells secrete lysosomes which are taken up by dendritic cells

Cell numbers of multiple immune cell substes, and mainly dendritic cells, are decreased over time in melanoma tumors.

Tumor antigens are drained into sentinel lymph nodes independently of dendritic cell migration.

Higher doses of immunmotherapy do not induce tumor regression when administrated to large melanoma lesions.

The recent success of checkpoint blockade therapies has established immunotherapy as one of the most promising treatments for melanoma. Nonetheless, a complete curative response following immunotherapy is observed only in a fraction of patients. To identify what factors limit the efficacy of immunotherapies, we established mouse models that cease to respond to immunotherapies once their tumors exceed a certain stage. Analysis of the immune systems of the organisms revealed that the numbers of tumor-infiltrating dendritic cells (TIDC) drastically decreased with time. Further, in contrast to the current paradigm, once melanoma was established, TIDC did not migrate into sentinel lymph nodes. Instead, they underwent local cell death due to excessive phagocytosis of lysosomes. Importantly, TIDC were required to license the cytotoxic activity of tumor CD8+ T cells, and in their absence, T cells did not lyse melanoma cells. Our results offer a paradigm shift regarding the role of TIDC and a framework to increase the efficacy of immunotherapies. Significance: This work redefines the role of monocyte-derived dendritic cells in melanoma and provides a novel strategy to increase the efficacy of T-cell–based immunotherapies in nonresponding individuals.

Background The molecular basis of unilesional mycosis fungoides (MF), characterized by a solitary lesion that is clinicopathologically indistinguishable from multifocal patch or plaque MF (early MF), is unknown. Objectives To investigate the microRNA profile in unilesional MF distinguishing it from early MF. Methods Biopsy samples of unilesional MF and early MF were evaluated with the Affymetrix microRNA array, with further comparison with inflammatory dermatosis, using quantitative polymerase chain reaction. NanoString technology was applied to analyse the gene expression of T helper (Th)1 immune markers, and immunohistochemistry was used to evaluate CXCR3 and GATA-binding protein 3 (GATA3) markers for Th1 and Th2 cells, respectively. Results Unilesional MF had a significantly higher level of expression of all members of the microRNA miR-17~92 cluster than early MF. Specifically, unilesional MF had a higher miR-17 level than early MF and inflammatory dermatoses. There was downregulation of the expression of phosphatase and tensin homolog (PTEN) and CREB1, known targets of miR-17~92 members; higher gene expression of interleukin-2 and interferon-γ; and a statistically lower average percentage of GATA3+ dermal cells (6·7% vs. 42·3%), were detected in unilesional MF compared with early MF. High immunoreactivity of CXCR3 was noted in both unilesional and early MF. Conclusions Unilesional MF exhibits a microRNA profile distinct from that of conventional early MF, with a higher level of miR-17~92 members along with Th1 skewing. These findings suggest a robust reactive T-cell immune response in unilesional MF and might account for the localized nature of this disease.

Whole organ perfusion decellularization has been proposed as a promising method to generate non-immunogenic organs from allogeneic and xenogeneic donors. However, the ability to recellularize organ scaffolds with multiple patient-specific cells in a spatially controlled manner remains challenging. Here, we propose that replacing donor endothelial cells alone, while keeping the rest of the organ viable and functional, is more technically feasible, and may offer a significant shortcut in the efforts to engineer transplantable organs. Vascular decellularization was achieved ex vivo, under controlled machine perfusion conditions, in various rat and porcine organs, including the kidneys, liver, lungs, heart, aorta, hind limbs, and pancreas. In addition, vascular decellularization of selected organs was performed in situ, within the donor body, achieving better control over the perfusion process. Human placenta-derived endothelial progenitor cells (EPCs) were used as immunologically-acceptable human cells to repopulate the luminal surface of de-endothelialized aorta (in vitro), kidneys, lungs and hind limbs (ex vivo). This study provides evidence that artificially generating vascular chimerism is feasible and could potentially pave the way for crossing the immunological barrier to xenotransplantation, as well as reducing the immunological burden of allogeneic grafts.

Background/purpose This study examined clinical and histological parameters of primary dermal melanoma (PDM) to aid in its distinction from dermal metastasis. Methods Retrospective analysis of a prospective cohort of PDM patients. Includes patients fulfilling the strict histologic criteria for PDM ( N = 9) and patients who did not, but clinically, unequivocally had an intradermal melanoma—clinical PDM (cPDM; N = 17). Histopathology slides were re-examined. Prognosticators and outcome measures were compared between groups. Sentinel nodes’ retrieval and wide local excision (WLE) were offered to all patients as primary treatment. Results 26 patients identified, 15 females with a median age of 69 years (range 3.5-85). Mean Breslow was 7.9 ± 5.7 mm (median 5.8, range 1.8-25.0), and the mean mitotic rate was 4.9 ± 3.8/mm2 (median 4.0, range 0-17). Initial treatment and follow-up were as for cutaneous melanoma. One patient in each group with a palpable stage III underwent primary radical dissection. Sentinel nodes were retrieved in all 20 lymphatic mappings performed and found to be metastatic in 5 (25%) patients. Treatment consisted of completion lymph-node dissection. At a median postoperative follow-up of 62 months (range 8-132), 20 patients were disease-free, including 6 of 7 patients with stage III disease at presentation. Six patients died all of cPDM; 5 of 6 patients had primary ulcerated or epidermal-abutting melanomas. Conclusions This is the first study to highlight cPDM. Diagnosis requires expert pathology review and a tight correlation to the clinical parameters. Patients seem to benefit from WLE with sentinel node retrieval and complete dissection when appropriate. However, clinical guidelines for dissection have changed since the time period of this retrospective review. Based on this series, complete nodal dissection in these melanomas is associated with better than expected outcome, for stage III disease.

Despite the remarkable success of immunotherapy in cancer, most patients will develop resistant tumors. While the main conceptual paradigm suggests that relapsed clones emerge through a process of clonal selection and immunoediting, currently little evidence directly demonstrates this process in epithelial cancers.To study this process, we established several mouse models in which tumors drastically regress following immunotherapy, yet resistant tumors relapse within a few weeks of treatment cessation. Whole exome analyses indicated that relapsed tumors share hundreds of neo-antigens with the primary tumors and are comparably killed by reactive T cells. Examination of tumor cells that survive immunotherapies revealed that they structure a transient cell-in-cell formation, which is impenetrable to immune-derived cytotoxic compounds and to chemotherapies. This formation is mediated predominantly by a cell-membrane protein on activated T cells, which subsequently induces epidermal growth factor receptors and STAT3 phosphorylation in tumors cells. In contrast to previous reports on cell-in-cell formations, here both cells remain alive and can disseminate into single tumor cells once T cells are no longer present.Overall, this work highlights a powerful resistance mechanism which enable tumor cells to survive immune pressure and provides a new theoretical framework for combining chemotherapies and immunotherapies.

Recent studies suggest that folliculotropic mycosis fungoides (FMF), the most common variant of mycosis fungoides (MF), presents with 2 distinct clinicopathological stages: early indolent stage and more aggressive advanced/tumour stage. To further characterize these stages, miR-155 expression was studied with qRT-PCR and found to be significantly higher in biopsies of tumour-stage FMF compared with early-stage FMF and inflammatory dermatoses. There was no statistically significant difference in miR-155 expression between early-stage FMF and early-stage MF, nor between tumour-stage FMF and tumour-stage MF. Immunohistochemical analysis revealed a significantly increased number of dermal Ki-67+ proliferating lymphocytes in tumour-stage FMF, together with an increased number of CD20+ B cells and CD68+ macrophages compared with early-stage FMF. Thus, similar to classic MF, miR-155, Ki-67 tumour cell immunoreactivity, and certain tumour-infiltrating inflammatory cells are differentially expressed in early- vs tumour-stage FMF. The results of this study corroborate the notion that FMF presents with 2 distinct stages.

Background/objectives Lichen sclerosus is a rare, pruritic, mucocutaneous disease affecting mostly the anogenital area. Reports have occasionally associated lichen sclerosus with overlapping vascular lesions. This study explores this association in children. Methods A retrospective study was conducted in the dermatology unit of a pediatric tertiary care medical center. Electronic medical records were searched for patients diagnosed with lichen sclerosus from 2006 to 2019. Review of the cases was performed to identify overlapping vascular lesions and review the clinical course of overlap cases. Results Of 74 children diagnosed with lichen sclerosus during the study period, five (6.75%) had overlapping vascular lesions and genital lichen sclerosus. Four patients presented with reticular telangiectatic macules and patches (n = 4, 5.4%) that appeared at or shortly after disease onset; resolution occurred a few months after treatment initiation. The fifth patient presented with telangiectases that appeared more than 2 years after the onset of the first symptoms of lichen sclerosus (n = 1, 1.3%). Conclusion Vascular lesions in children with genital lichen sclerosus are common and have variable clinical manifestations. Early appearance of reticular macules, patches, and papules is a variant of the disease and is followed by prompt resolution of these lesions. Pathogenesis is attributed to structural changes and repositioning of the papillary vascular plexus. These changes may be alarming to parents and therefore must be recognized by physicians to prevent unnecessary concern and investigations.

Systemic doxorubicin is effective for desmoid fibromatosis (DF), but its use is limited by dose-dependent cardiotoxicity. A protocol of selective intra-arterial doxorubicin drug-eluting embolization (DEE) was designed to maximize target tissue efficacy of doxorubicin, while minimizing systemic exposure. Four children with recurrent or refractory DF were treated between 2014 and 2017. Tumor volumes were reduced by 54%-97% over a follow-up interval of 6-32 months. A single patient experienced transient lower extremity paresthesia (Common Terminology Criteria for Adverse Events grade I). Further investigation is needed to better establish these promising results for doxorubicin DEE in DF treatment.

Data on the treatment of early folliculotropic mycosis fungoides, a recently defined clinicopathological subgroup of folliculotropic mycosis fungoides with an indolent course, is limited. Treatment outcomes were studied in a retrospective cohort of 47 adults with early folliculotropic mycosis fungoides, with a focus on psoralen plus ultraviolet A (PUVA) monotherapy, including dosimetric data, and the findings were compared with data for PUVA in 18 adults with early-classic mycosis fungoides. PUVA was given to 27 patients with early folliculotropic mycosis fungoides: 70% achieved complete response and 26% partial response. Significantly more treatments were needed to achieve complete response in stage IB compared with stage IA. There was no significant difference in the complete response rate from classic plaque-stage disease, although the early folliculotropic mycosis fungoides group required more treatments to achieve complete response, and a higher cumulative dose of UVA. Thus, PUVA is an effective treatment for early folliculotropic mycosis fungoides. Its complete response rate might be equal to early-classic mycosis fungoides; however, a longer induction phase is needed to achieve complete response.

Nevi and melanocytic proliferations are known to appear in multiple extracutaneous sites, including lymph nodes and meninges. We report a case of an anterior mediastinal mass in a patient with a giant congenital nevus and neurofibromatosis type I. Histologically, the tumor was found to be a malignant melanoma in the thymus arising in association with a nevus that involved most of the thymic tissue. There was no sign of cutaneous melanoma on skin examination. We suggest that the tumor originated from the benign nevus in the thymus, a rare extracutaneous location for nevi and malignant melanoma.

Ependymoma is a malignant pediatric brain tumor, often incurable under the current treatment regimen. We aimed to evaluate the expression of microRNAs (miRs) in pediatric ependymoma tumors in an attempt to identify prognostic molecular markers which would lead to potential therapeutic targets. Following miR-array expression analysis, we focused on 9 miRs that correlated with relapse which were further validated by quantitative real-time PCR (qRT-PCR) in a cohort of 67 patients. Western blotting and immunohistochemistry were used to measure target protein expression in 20 and 34 tumor samples, respectively. High expression of miR-124-3p significantly correlated with the lower progression-free survival (PFS) of 16% compared to 67% in those expressing low levels (P = .002). Interestingly, in the group of patients with local disease (n = 56) expression levels of this miR distinguished 2 subgroups with a significantly different outcome (P = .001). miR-124-3p was identified as an independent prognostic factor of relapse in the multivariate analysis performed in the whole cohort and in the group with localized disease. In the localized group, a patient expressing high levels of miR-124-3p had a 4.1-fold increased risk for relapse (P = .005). We demonstrated the direct binding of miR-124-3p to its target TP53INP1. Negative TP53INP1 protein levels correlated with a poor outcome (P = .034). We propose miR-124-3p and TP53INP1 as new biomarkers for prognostic stratification that may be possible therapeutic targets for ependymoma.

SummaryBackground Primary cutaneous marginal zone B-cell lymphoma (PCMZL) has rarely been reported in patients younger than 20 years. Objectives To report our experience with PCMZL in the paediatric/adolescent age group. Methods Medical records of patients diagnosed with PCMZL before age 20 years and managed at two cutaneous lymphoma clinics in the United States and Israel in 1992-2015 were reviewed. Results The study group included 11 patients (6 girls) of median age 16 years (range 6–19.5); 10 had generalized/multifocal (T3) and 1 had regional/localized (T2) disease. Lesions were located on the limbs in all patients and the trunk in 6; 2 had facial lesions. Staging in all but one was based on whole-body computed tomography or positron emission tomography. Initial management in most patients included non-radiation modalities: 1 patient with localized disease received intralesional steroids; 6 patients with multifocal disease received the following: 3 - topical/intralesional steroids, 2 - excision, 1 - “watch and wait”. No extracutaneous progression was noted during a median follow-up of 5.5 years (mean 7.5, range 0.5-14). At present, 5/11 patients are in complete remission. Conclusions Based on our data (largest series in the literature with the longest follow up); the clinico-pathological presentation and course of PCMZL in the paediatric/adolescent age group are similar to adults. Given the indolent course and the long life expectancy of these young patients, the cumulative risk of imaging studies and the age-related potential toxicity of treatment, especially radiation, should be taken into consideration. This article is protected by copyright. All rights reserved.

We report the unexpected absence of early relapse (before 30 months) in 24 consecutive patients with isolated limb primary Ewing sarcoma treated with an intensified pilot protocol, SCMCIE94. Clinical data for the study were collected retrospectively from the patient files. The protocol included 6 courses of chemotherapy, split radiation, and limb salvage surgery. This SCMCIE94 protocol had been used in almost all the patients described in an earlier report, in whom those with non-pelvic isolated tumors and low/absent CD56 expression in Ewing sarcoma tumor cells were all long-term survivors. The 5-year (10-year) event-free survival rate for the patients with isolated limb primary Ewing sarcoma was 78.95 ± 8.3% (68.6 ± 10.0%) and the overall survival rate was 90.7 ± 6.2% (71.1 ± 11.2%). There were no relapses before 30 months in any of these patients. The intensified SCMCIE94 pilot protocol has been shown previously to cure patients with localized CD56-negative non-pelvic Ewing sarcoma. The present study shows that among all patients with localized extremity disease who were treated with this protocol, there were no cases of early relapse. Although our cohort was small, the difference in results from studies using other protocols is so striking, that it would seem reasonable to assume it is attributable to the changes made in the protocol itself rather than risk factors. Late relapses of isolated limb CD56-positive Ewing sarcoma suggest minimal residual disease warranting additional therapeutic approaches such as autologous stem cell rescue after Busulfan Melfelan.

9045 Background: Immune checkpoint inhibitors (ICI) have become the standard treatment for metastatic NSCLC, although only a small proportion of patients derive durable benefit. PDL1 expression is the only approved biomarker to select NSCLC patients for treatment with single-agent pembrolizumab, however its predictive value is limited and better predictive biomarkers are needed. The spatial arrangement of immune cells in the tumor microenvironment (TME), namely tumor infiltrating lymphocytes (TILs), emerges as a potential biomarker for ICI efficacy. In this work, we utilized deep-learning (DL) models to extract TME features from digitized H&E slides and evaluated their predictive and prognostic role in patients with mNSCLC treated with Pembrolizumab. Methods: NSCLC patients (n=90) treated with single-agent 1st line pembrolizumab in two centers were identified. 47 patients from one center were used to train the model, and 43 patients from another center were used for validating the model. Pre-treatment H&E whole slide images (WSI) were analyzed using a deep-learning model to identify and classify tumor cells, TILs, tumor and stromal areas, and spatial features were calculated. Spatial features were correlated with clinical outcome data to train a binary classifier that identifies patients with a favorable clinical outcome. The resulting classifier combined three spatial features and three clinical features. The classifier was then applied to the validation set and differences in duration of treatment (DOT), and overall survival (OS) between patients with positive and negative scores were assessed. Results: The classifier identified patients in the validation set to have either positive (n=18) or negative (n=25) scores. Baseline patient characteristics and PDL1 score were similar between the positive and negative groups. In a Kaplan-Meier (KM) analysis, OS was significantly higher in patients with a positive score compared to patients with a negative score (HR=0.35, 95% CI 0.13-0.98; p

Aims The distinction between benign and malignant thyroid nodules has important therapeutic implications. Our objective was to develop an assay that could classify indeterminate thyroid nodules as benign or suspicious, using routinely prepared fine needle aspirate (FNA) cytology smears. Methods A training set of 375 FNA smears was used to develop the microRNA-based assay, which was validated using a blinded, multicentre, retrospective cohort of 201 smears. Final diagnosis of the validation samples was determined based on corresponding surgical specimens, reviewed by the contributing institute pathologist and two independent pathologists. Validation samples were from adult patients (≥18 years) with nodule size >0.5 cm, and a final diagnosis confirmed by at least one of the two blinded, independent pathologists. The developed assay, RosettaGX Reveal, differentiates benign from malignant thyroid nodules, using quantitative RT-PCR. Results Test performance on the 189 samples that passed quality control: negative predictive value: 91% (95% CI 84% to 96%); sensitivity: 85% (CI 74% to 93%); specificity: 72% (CI 63% to 79%). Performance for cases in which all three reviewing pathologists were in agreement regarding the final diagnosis (n=150): negative predictive value: 99% (CI 94% to 100%); sensitivity: 98% (CI 87% to 100%); specificity: 78% (CI 69% to 85%). Conclusions A novel assay utilising microRNA expression in cytology smears was developed. The assay distinguishes benign from malignant thyroid nodules using a single FNA stained smear, and does not require fresh tissue or special collection and shipment conditions. This assay offers a valuable tool for the preoperative classification of thyroid samples with indeterminate cytology.

Amelanotic melanomas (AMMs) account for a small proportion of all melanomas. They pose a risk of delayed diagnosis and, consequently, poor prognosis. AMMs may atypically present as a pyogenic granuloma-like lesion. This study sought to investigate the prevalence and clinical and histological features of AMM masquerading as pyogenic granuloma. The database of a tertiary medical center was screened for all patients pathologically diagnosed with melanoma in 2005-2016. Those with a suspected primary (i.e. pre-excision) clinical diagnosis of pyogenic granuloma were identified, and their demographic, clinical, histologic, and outcome data were collected from the medical files. Of 2038 patients diagnosed with melanoma, 10 (∼0.5%) had a pyogenic granuloma-like AMM. The mean±SD age at lesion presentation was 56±18.9 years and the mean time from lesion appearance to diagnosis was 91.5±117.1 months. Nine tumors were located on the skin surface, and one on the oral mucosa. The mean lesion size was 19.6±14.1 mm and the mean Breslow's depth was 6.47±3.1 mm; all tumors presented in the vertical growth phase. Seven (70%) patients had lymph node involvement or metastasis at diagnosis. Two patients died of the disease within 1 year of diagnosis. Given the potential lethality of AMM and the benign nature of pyogenic granuloma, clinician recognition of pyogenic granuloma-like AMMs is crucial. In the presence of a pyogenic granuloma-like lesion, findings of older patient age and large tumor size should raise the index of suspicion and prompt a biopsy study, thereby ensuring early and accurate treatment.

Ewing Sarcoma (ES) is the second most common primary malignant bone tumor in children and adolescents. microRNAs (miRNAs) are involved in cancer as tumor suppressors or oncogenes. We studied the involvement of miRNAs located on chromosomes 11q and 22q that participate in the most common translocation in ES. Of these, we focused on 3 that belong to the let-7 family. We studied the expression levels of let-7a, and let-7b and detected a significant correlation between low expression of let-7b and increased risk of relapse. let-7 is known to be a negative regulator of the RAS oncogene. Indeed, we detected an inverse association between the expression of let-7 and RAS protein levels and its downstream target p-ERK, following transfection of let-7 mimics and inhibitors. Furthermore, we identified let-7 as a negative regulator of HIF-1α and EWS-FLI-1. Moreover, we were able to show that HIF-1α directly binds to the EWS-FLI-1 promoter. Salirasib treatment in-vitro resulted in the reduction of cell viability, migration ability, and in the decrease of cells in S-phase. A significant reduction in tumor burden and in the expression levels of both HIF-1α and EWS-FLI-1 proteins were observed in mice after treatment. Our results support the hypothesis that let-7 is a tumor suppressor that negatively regulates RAS, also in ES, and that HIF-1α may contribute to the aggressive metastatic behavior of ES. Moreover, the reduction in the tumor burden in a mouse model of ES following Salirasib treatment, suggests therapeutic potential for this RAS inhibitor in ES.

Malignant mesothelioma is an uncommon tumor that usually arises in the pleural cavity of adults with a history of asbestos exposure. Less frequently, it appears in the peritoneum or other mesothelial surfaces. Deciduoid mesothelioma is a rare subtype that has been found at both sites. Of the 3 reported cases in children, 2 originated in the mesenterium and 1 in the pleura. We describe a 4th case of pediatric, malignant, deciduoid mesothelioma and a third case in the mesenteric cavity. The patient was an 8-year-old girl who presented with abdominal pain and fullness. Workup revealed extensive involvement of the abdomen by a serosa-based tumor. The clinical and pathologic findings are described, and the pertinent literature is reviewed.

Acinic cell carcinoma of the parotid gland is a rare low-grade malignant neoplasm. Data on children are sparse. For the present study, the database of a tertiary pediatric medical center was reviewed for all patients with parotid gland acinic cell carcinoma diagnosed and treated between 2004 and 2013. Clinical, histologic, treatment, and outcome parameters were collected from the medical files. Four patients were identified, 3 female and 1 male, aged 13.5 to 18 years (median 15.7) at diagnosis. One patient had a family history of parotid tumor and 1 of hypothyroidism/hyperthyroidism. Two patients had L-thyroxin-treated Hashimoto thyroiditis, and 1 had a thyroid nodule. All presented with a localized parotid mass and negative lymph nodes. Treatment consisted of partial parotidectomy, with no damage to the facial nerve. Histology confirmed the diagnosis of acinic cell carcinoma with low proliferation rate (Ki67 immunostaining 1% to 8%). No evidence of disease was found on any patient with a median follow-up at 83 months (range, 32 to 93 mo) from presentation. In our experience, the prognosis of pediatric parotid gland acinic cell carcinoma is good, and surgery alone is sufficient for treatment of early stage tumors. This is the first report of findings of a family history of thyroid disease and/or thyroid abnormalities in patients with parotid gland acinic cell carcinoma.

Background Unilesional folliculotropic mycosis fungoides (UFMF) has been rarely reported. Objective The aim of this study was to describe our experience with UFMF. Methods Data were collected on all patients with clinicopathological UFMF who attended the Department of Dermatology of a tertiary university-affiliated medical centre in 1996–2013 and were followed prospectively. Results The sample included seven patients (five male, two female) of mean age 38 years at diagnosis; two were aged

Background The literature on mycosis fungoides (MF) in children/adolescents is sparse. Objective We sought to evaluate the characteristics of juvenile MF in a large cohort. Methods Data were collected on all patients with MF, aged 18 years or younger at the time of clinicopathologic diagnosis, who attended the Rabin Medical Center Dermatology Department, Petach Tikva, Israel, between 1994 and 2012 and were followed up prospectively. Results There were 50 patients (30 male; mean age 11.4 years at diagnosis); 18 (36%) had Fitzpatrick skin type IV or higher. All were given a diagnosis of early-stage disease (IA-IIA) except 1 (tumor stage, IIB). Eight had classic MF lesions only and 42 had other variants, alone or in combination; these were mainly hypopigmented MF (n = 29) and cases with subtle but clear clinicopathologic features of folliculotropic MF (FMF) (n = 18). Among the various skin-targeted therapies, psoralen plus ultraviolet A (systemic/bath) proved beneficial for FMF. During a follow-up period of 0.25 to 15 years (mean 4.5), 2 patients progressed from stage IA to IB or IIA. Limitations Relatively short follow-up is a limitation. Conclusions This case series shows that FMF is not uncommon in children and adolescents. It is characterized by more superficial clinical features and less heavy perifollicular lymphocytic infiltrates than adult FMF, and responds well to psoralen plus ultraviolet A. The prognosis of childhood FMF remains unclear.

Ependymoma is a malignant pediatric brain tumor, often incurable under the current treatment regimen. We aimed to evaluate the expression of microRNAs (miRs) in pediatric ependymoma tumors in an attempt to identify prognostic molecular markers which would lead to potential therapeutic targets. Following miR-array expression analysis, we focused on 9 miRs that correlated with relapse which were further validated by quantitative real-time PCR (qRT-PCR) in a cohort of 67 patients. Western blotting and immunohistochemistry were used to measure target protein expression in 20 and 34 tumor samples, respectively. High expression of miR-124-3p significantly correlated with the lower progression-free survival (PFS) of 16% compared to 67% in those expressing low levels (P = .002). Interestingly, in the group of patients with local disease (n = 56) expression levels of this miR distinguished 2 subgroups with a significantly different outcome (P = .001). miR-124-3p was identified as an independent prognostic factor of relapse in the multivariate analysis performed in the whole cohort and in the group with localized disease. In the localized group, a patient expressing high levels of miR-124-3p had a 4.1-fold increased risk for relapse (P = .005). We demonstrated the direct binding of miR-124-3p to its target TP53INP1. Negative TP53INP1 protein levels correlated with a poor outcome (P = .034). We propose miR-124-3p and TP53INP1 as new biomarkers for prognostic stratification that may be possible therapeutic targets for ependymoma.

Background It is generally accepted that folliculotropic mycosis fungoides (FMF) is usually typified by indurated plaques and tumors mainly on the head/neck and an aggressive course. However, its clinical manifestations have long been recognized to be quite variable, and some studies indicate a better prognosis for certain presentations. Objective We sought to summarize our experience with the clinicopathological presentations of FMF and impact on prognosis. Methods Data were collected retrospectively for adults with FMF followed up prospectively at a tertiary medical center in 1995 through 2014. Results In all, 34 patients presented with follicle-based patch/flat plaques, keratosis pilaris–like lesions, and/or acneiform lesions, defined clinically as early stage (IA, IB), and 15 presented with follicle-based infiltrated plaques and/or tumors, defined as advanced stage (IIB). The head/neck was involved in all tumor-stage cases, whereas early-stage lesions involved mainly the trunk/limbs. The tumor stage was characterized by more pruritus, heavier perifollicular infiltrates, greater vertical depth, and more frequent presence of eosinophils. On multivariate analysis, infiltrate density was the only significant histopathological discriminator between the stages. Estimated 5-year survival was 0.94 in the early-stage group and 0.69 in the tumor-stage group. Limitations Lack of long-term follow-up and relatively small sample are limitations. Conclusion FMF presents with 2 distinct patterns of clinicopathologic features, early stage and advanced stage, each with different prognostic implications.

Background Some authorities consider alopecia mucinosa (AM)/follicular mucinosis (FM) to invariably represent mycosis fungoides (MF). This understanding of AM/FM derives from observations in adults. Objectives We sought to explore the clinicopathologic features and natural history of pediatric AM/FM. Methods Medical records were searched for children given the diagnosis of AM/FM from 1998 through 2009. Diagnosis of AM/FM was defined as the presence of well-demarcated hairless plaques with follicular prominence plus an abundance of mucin on histopathologic examination. Results Forty children with a clinical diagnosis of AM/FM were identified. Nine did not meet the inclusion criteria. In the 31 remaining cases (16 boys, 15 girls) the mean age at onset was 9 ± 3.5 years. Histopathologic examination showed folliculotropism in 28 patients (90%) and epidermotropism in 15 (48%). Twelve cases fulfilled the International Society of Cutaneous Lymphomas (ISCL) diagnostic criteria for early MF. The histopathologic findings were typical of MF in only in two of these cases. T-cell receptor gene rearrangement was positive in 3 of 6 (50%) of tested samples, one in a patient who fulfilled the ISCL criteria for early MF. Mean duration of follow-up was 6.2 ± 3.7 years. All skin lesions resolved and none persisted or recurred. Hodgkin lymphoma was diagnosed 6 months after diagnosis of AM/FM in one patient. Limitations This was a retrospective study. Conclusions Although some pediatric cases meet the diagnostic criteria for MF, AM/FM cannot be regarded unequivocally as early follicular MF in this age group. We suggest the current diagnostic criteria for early MF should exclude children with AM/FM. Long-term follow-up of children with AM/FM is nevertheless warranted.

Background. Cancers of unknown primary origin (CUP) constitute 3%–5% (50,000 to 70,000 cases) of all newly diagnosed cancers per year in the United States. Including cancers of uncertain primary origin, the total number increases to 12%–15% (180,000 to 220,000 cases) of all newly diagnosed cancers per year in the United States. Cancers of unknown/uncertain primary origins present major diagnostic and clinical challenges because the tumor tissue of origin is crucial for selecting optimal treatment. MicroRNAs are a family of noncoding, regulatory RNA genes involved in carcinogenesis. MicroRNAs that are highly stable in clinical samples and tissue specific serve as ideal biomarkers for cancer diagnosis. Our first-generation assay identified the tumor of origin based on 48 microRNAs measured on a quantitative real-time polymerase chain reaction platform and differentiated 25 tumor types. Methods. We present here the development and validation of a second-generation assay that identifies 42 tumor types using a custom microarray. A combination of a binary decision-tree and a k-nearest-neighbor classifier was developed to identify the tumor of origin based on the expression of 64 microRNAs. Results. Overall assay sensitivity (positive agreement), measured blindly on a validation set of 509 independent samples, was 85%. The sensitivity reached 90% for cases in which the assay reported a single answer (>80% of cases). A clinical validation study on 52 true CUP patients showed 88% concordance with the clinicopathological evaluation of the patients. Conclusion. The abilities of the assay to identify 42 tumor types with high accuracy and to maintain the same performance in samples from patients clinically diagnosed with CUP promise improved utility in the diagnosis of cancers of unknown/uncertain primary origins.

Background Human herpesvirus (HHV) 8, an essential etiologic agent of Kaposi sarcoma, is also associated with several lymphoproliferative disorders. The involvement of HHV 8 in mycosis fungoides (MF) and large plaque parapsoriasis (LPP) is controversial, with contradictory reports from various countries worldwide. Objective We sought to investigate the presence of the HHV 8 genome in skin lesions of LPP and early-stage sporadic, familial, and juvenile MF in patients in Israel. Methods Archival paraffin-embedded and frozen samples from skin biopsies of untreated patients with LPP and early-stage MF performed in 1990 through 2006 were randomly collected from the department of dermatology of a tertiary medical center in central Israel. DNA was extracted, and a TaqMan-based real-time polymerase chain reaction assay specific for the K6 gene region was used to detect the HHV 8 genome. Results A total of 46 biopsies were sampled from 11 patients with LPP and 35 with early-stage MF (17 adults with sporadic MF, 10 children, and 8 patients with familial MF). In all, 44 samples were negative for HHV 8 DNA; two samples from adults with sporadic MF were positive. Limitations The presence of HHV 8 antibodies or virus sequences was not assessed in peripheral blood. Conclusion The results of this study, conducted in a region relatively endemic for HHV 8, support most earlier studies showing a lack of association of HHV 8 infection with LPP and sporadic adult-type MF. To our knowledge, the lack of association of HHV 8 infection with juvenile and familial MF has not been previously reported.

Background Lentigines are a common pigmentary disorder in adults and in patients treated by psoralen and ultraviolet A (PUVA) radiation. Their appearance following treatment with narrow-band ultraviolet B (NB-UVB) radiation has been reported in only two patients. Objective To describe the clinical and histological features of NB-UVB-induced lentigines their relation to dosimetry and the course of the eruption in patients with mycosis fungoides (MF). Methods The files of all patients with MF treated in our department in 2003–2010 were searched to identify those in whom lentigines appeared following monotherapy with NB-UVB radiation. Results Of the 73 patients with early stage MF identified, 10 met the study criteria. Lentigines were detected in skin previously involved by MF in seven patients, and in both involved and uninvolved skin in three patients. They appeared during therapy in three patients, after a mean of 56 exposures (range 50–61), and several months (mean 7.8) following completion of treatment in seven patients, after a mean of 69 exposures (range 32–157). Histopathological study of lesions from five patients revealed basal hyperpigmentation relative to adjacent normal-looking skin. Two lesions had a slight increased number of normal-looking melanocytes on immunohistochemical staining with melanoma cocktail. One lesion had elongated rete ridges. The lesions persisted throughout follow-up (mean 26.7 months) in 8 patients. Conclusions Patients with MF treated with NB-UVB may acquire lentigines. As opposed to PUVA-induced lentigines which are a known common side-effect of long-term treatment, NB-UVB-induced lentigines are uncommon but appear earlier, even after a few months of treatment.

Ependymoma is a malignant pediatric brain tumor, often incurable with current treatment regimens. We aimed to identify new genes involved in pediatric ependymoma using copy number SNP array analysis. We analyzed 34 primary tumors, in 10 cases we analyzed the paired diagnosis-relapse samples and in 5 of them we also analyzed the corresponding peripheral blood (PB) sample. The most prevalent alterations identified were gain of 8q (18%), deletion of 10q (18%), gain of 11q (12%) and gain of 17q (53%). The locus of the 17q21.31 gain contains only one gene - KANSL1 (KAT8 regulatory NSL complex subunit 1) gene. The gain affected exons 1–4 of the gene. This gain was identified in 9 out of the 10 (90%) relapse samples and in all of the PB samples. The gain was validated at the RNA level and a significant overexpression of KANSL1 mRNA was detected in the samples exhibiting gain versus the samples with normal copy number (p=0.04). KANSL1 is part of the NSL complex which functions as a histone acetyltransferase. The 17q21.31 locus contains a common inversion duplication polymorphism enriched in European populations. Recently, a new fusion was discovered in high frequencies in adult malignancies between KANSL1 and ARL17, termed KANSARL, both located on 17q21.31. KANSARL fusion was detected in 71% of our samples. All the samples that exhibited gain of KANSL1 were positive for the KANSARL fusion. Our results suggest that the gain precedes the formation of the fusion which may be a predisposing event in ependymoma.

Summary Background Cutaneous lymphomas rarely occur in children and adolescents, and are mostly of the T-cell lineage. Low-grade primary cutaneous B-cell lymphoma (CBCL) is extremely rare in individuals under 18 years old. Only 11 patients under 20 years old have been reported in the literature. Objectives To evaluate the number of patients younger than 18 years with primary CBCL diagnosed at our centre and to investigate its clinicopathological features, treatment and course in this age group. Methods We reviewed the files of all 90 patients with primary CBCL who attended the Department of Dermatology of our tertiary care university-affiliated centre from 1992 to 2007. Results Four patients who met study criteria were identified: three girls and one boy. Mean age at diagnosis was 16·6 years (range 16–17). Three patients had cutaneous marginal zone lymphoma (CMZL), and one had a spindle-cell (sarcomatoid) lymphoma, most probably follicular centre cell type. All were treated with the standard regimen used in adults. The mean duration of follow up was 45 months. No extracutaneous progression was noted. At present two of the four patients are in complete clinical remission. Conclusions In Israel, primary CBCL apparently occurs more often in young patients than reported in the literature. CMZL is the most frequent type. Long follow up is mandatory to assess the biological behaviour of CBCL in the paediatric/adolescent age group.