Characteristic Translocation Research Articles

Characterization and modulation of the unimolecular conformation of integrins with nanopore sensors

Integrins are a large family of heterodimeric mammalian transmembrane receptors that connect extracellular matrix (ECM) and the cytoskeleton. Integrin-mediated adhesion governs the cellular adhesion, mobility, and cell mechanobiology. Investigations on different integrins in cellular and the conformation change regulated by divalent metal ions and oligopeptides have been documented, they mainly adopted the cellular assays or surface manipulation to achieve the information of ensemble integrins with proteins and small molecules. This work presents the nanopore approach for the characterization of unimolecular integrin via resistive pulse sensing. The orientation selection in distinct nanopore in size and pH condition discloses the tiny disparity of the conformation and the local surface charge distribution. The divalent metal ions could efficiently modulate the conformation alteration of integrin, in which Ca2+ and Mn2+ could activate integrin αLβ2 to take larger physical dimension than Mg2+, and Ca2+ is superior to Mn2+ in the activation when integrin αLβ2 is treated in the mixed metal ions. The oligopeptide cRGD (cyclic Arg-Gly-Asp) and its derivatives cRGDfk and cRGDyk show specific binding with integrin αVβ3 and the complex of αVβ3-cRGD exhibits largest geometry upon Ca2+-mediation with characteristic nanopore translocation feature. This work provides a platform for unimolecular integrin sensing and the modulation of the local conformation transition regulated by divalent metal ions and oligopeptides, which will be valuable for the representation of integrin-related cellular behavior and bio-function.

Adamantinoma-like ewing sarcoma arising in the pancreatic tail: a case report of a rare entity and review of the literature

ALES is a rare subtype that demonstrates the EWSR1-FLI1 translocation characteristic of ES and demonstrates complex epithelial differentiation including diffuse cytokeratin and p40 expression. It has predominantly recognized in the head and neck and is common in middle-aged population. This case is the first case of ALES reported in the pancreatic tail, sharing some morphological characteristics with ALES in the head and neck, including monotonous cytology, infiltrative growth pattern, and complex epithelioid differentiation, but ALES in the head and neck often has high-grade histological features (e.g., necrosis, high mitotic rate, etc.), and sudden keratinization can also occur, but these features were not reflected in this primary pancreatic tail ALES. Although ALES arising in the pancreatic tail and in the head and neck sites share the immunohistochemical and molecular profile, our case can provide new ideas in differential diagnosis of ALES arising in pancreatic tail and promote increased recognition and understanding of ALES.

Basic immunohistochemistry for lymphoma diagnosis.

Immunohistochemistry is a technique that uses antigen-antibody interactions to detect specific proteins in cells. This technique has several essential applications in lymphoma diagnosis, including identifying the cell lineage and phase of maturation, detecting specific genetic alterations, visualizing the degree of cell proliferation, and identifying therapeutic targets. CD3 is a pan T-cell marker expressed on most of the mature T/NK-cell lymphomas, except for anaplastic large cell lymphoma, whereas CD20 is a pan B-cell marker that is expressed on most of the mature B-cell lymphomas. CD79a may be a good alternative to CD20, compensating for its loss owing to the plasmocytic differentiation of tumor cells or history of rituximab administration. CD56, a neuroendocrine marker, is used as an NK cell marker in lymphoma diagnosis. Characteristic translocations occurring in follicular lymphoma (BCL2) and mantle cell lymphoma (CCND1) can be detected by the overexpression of Bcl-2 and cyclin D-1 in immunohistochemistry, respectively. Ki-67 reflects the degree of tumor cell proliferation by indicating cells in cell cycle phases other than G0. With the development of immunotherapy, several antibodies against markers such as programmed death-ligand 1 (PD-L1), CD19, and CD30 have been used as biomarkers to identify therapeutic targets. It is critical to properly fix the specimens to obtain accurate immunohistochemical results. Therefore, all processes, from tissue collection to the final pathological diagnosis, must be performed appropriately for accurate lymphoma diagnosis.

A small round blue cell tumour of the rib: A case report of Ewing sarcoma

Ewing sarcoma is a prototypical small round blue cell tumour with a characteristic EWSR1 translocation. We report a case of Ewing sarcoma arising in the rib of an 81-year-old female. The tumour was comprised of uniform small round cells which demonstrated an organoid growth pattern with a suggestion of rosette-like structures. Immunohistochemistry showed positive staining for CD99, vimentin and desmin; stains for cytokeratins, melanocytic markers, neuroendocrine markers, CD45, CD138, NFP and CD34 were negative. EMA and BCL2 demonstrated weak, patchy staining. FISH studies demonstrated an EWSR1 fusion, supporting the diagnosis of Ewing sarcoma. Desmin positivity, although recognised in Ewing sarcoma, has been reported in only 2% of cases.1 The main differential diagnosis based on morphology and immunohistochemistry was between Ewing sarcoma and synovial sarcoma due to CD99 positivity and focal EMA and BCL2 staining. However, EWSR1 translocations are not associated with synovial sarcoma.2 Recently a proportion of ‘undifferentiated round cell sarcomas’ with similar morphology to Ewing sarcoma have been divided into specific entities largely based on their molecular characteristics. These include CIC-rearranged sarcomas, sarcomas with BCOR alterations and round cell sarcomas with EWSR1-non ETS fusions.3

PCR- Negative Atypical PML-RARA Rearrangement in Pediatric Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) is a special type of acute myeloid leukemia (AML), accounting for about 5% to 10% of children with AML. At the genetic level, APL is featured by a unique chromosome translocation t(15;17) which results in the PML-RARA gene fusion. Most patients can be diagnosed by traditional karyotype analysis, Fluorescence-In-Situ Hybridization (FISH), or Reverse Transcription-Polymerase Chain Reaction (RT-PCR). We report the case of a child with acute promyelocytic leukemia (APL) who had characteristic chromosome translocation t(15;17) and rare PML-RARA gene mutation. This patient had an excellent response to chemotherapy, suggesting that this mutation will not affect the treatment and prognosis of APL.

Hispanic or Latin American Ancestry Is Associated with a Similar Genomic Profile and a Trend Toward Inferior Outcomes in Newly Diagnosed Multiple Myeloma As Compared to Non-Hispanic White Patients in the Multiple Myeloma Research Foundation (MMRF) CoMMpassstudy

IntroductionLarge clinical data sets suggest that the natural history and prognosis of newly diagnosed multiple myeloma (NDMM) differs between patients of European and African ancestry, with the latter group exhibiting an earlier age at onset and poorer overall prognosis in some studies. The use of next generation sequencing (NGS) to characterize the genomic landscape of multiple myeloma (MM) suggests that the observed phenotypic differences between these groups of patients may reflect distinct underlying genomic profiles and mutational processes. Thus far, characterizations of this type have focused principally on patients of African ancestry (AA). Here, we characterize the genomic features and outcomes of a large series of patients of Hispanic or Latin American ancestry (HL) as compared to their Non-Hispanic white (NHW) counterparts.MethodsSubjects were selected from the MMRF CoMMpass SM trial, a study that includes 1,154 patients with updated outcome data as of March, 2020. Within this data set, 760 patients had information on race and ethnicity. Among these, 55 HL patients and 478 NHW patients possessed complete clinical and genomic information.We analyzed baseline whole exome sequencing (WES) and long insert whole genome sequencing (WGS) as previously described (Walker, et al. Blood 2019). Our analysis focused on 63 known driver mutations in multiple myeloma and 39 sites of common copy number variation across the study population. Complex structural variants and tumor telomere length were called using previously described bioinformatic tools (Boyle et al. Leukemia 2021). Survival analysis was undertaken using the Kaplan-Meier method with hazard ratios determined by the Cox proportional hazards model.ResultsIn a comparison of clinical features between the Hispanic and NHW population, we did not identify any differences in age of onset, gender, presenting cytogenetics, International Staging System Score (ISS), and IMWG Risk Category. The proportion of patients undergoing autologous stem cell transplantation was similar between groups. We identified no statistically significant differences in the presence of characteristic translocations involving IgH locus or in hyperdiploidy status. No statistically significant differences in tumor mutational burden or loss-of-heterozygosity percentage emerged between HL and NHW patients.We examined non-synonymous variations (NSV) and copy number variations at the loci of known MM driver genes and encountered no statistically significant differences in NSV, copy number, or biallelic status. We further categorized genes into pathways relevant to the pathogenesis of MM and discovered no difference in the proportions of patients harboring mutations in genes related to the MEK/ERK and NF-κB pathways, cell cycle regulation, and epigenetic modification. We were unable to the distinguish either population based on the presence of chromothripsis or in the overall preponderance of an APOBEC mutational signature. Tumor telomere length was not significantly different between the populations.An analysis of overall and progression free survival (PFS) with a median duration of follow up of 44 months revealed a trend toward poorer outcomes among the HL population that did not reach statistical significance. Median PFS was 24 months in HL patients and 35 months in the NHW population (p = 0.19). Median OS was not reached in either ethnic subgroup. In terms of overall survival, age, ISS score, overall number of driver mutations, and the presence of chromothripsis emerged with a negative impact on outcome (Figures 1a, 1b). These variables with the exception of chromothripsis retained their significant impact on progression free survival (Figure 2a, 2b).ConclusionThe correlation between Hispanic or Latin American ancestry and underlying disease biology in MM has yet to be fully elucidated. In our analysis, which was based on self-declared ancestry as opposed to admixture, no obvious differences in significant measures of genomic variation known to impact prognosis in MM emerged between HL and NHW patients. These results may help to inform the future large-scale studies to ascertain the impact of genomics, disease biology and socioeconomic factors on outcomes in this heterogeneous patient population. [Display omitted] DisclosuresWalker: Bristol Myers Squibb: Research Funding; Sanofi: Speakers Bureau. Morgan: BMS: Membership on an entity's Board of Directors or advisory committees; Jansen: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees.

Revisiting Cytochemical Myeloperoxidase (MPO) Stain for Early Diagnosis of Acute Promyelocytic Leukemia (APML) in Areas with Limited Resources: An Experience from a Tertiary Care Center in India

Introduction- Acute Promyelocytic leukemia (APML) needs to be suspected early so that All-Trans Retinoic Acid (ATRA) therapy can be started as soon as possible. Flow cytometry shows absence of CD34 and HLADR in most cases and so can aid in diagnosis along with the usual morphological clues. However, it may have confusing patterns as in hypogranular APML and sometimes may be positive for HLA- DR and CD34. RT-PCR for detection of characteristic APML translocations (t(15;17),t(17;17) and others) is gold standard for APML diagnosis which is time consuming and often not possible especially in resource limited areas. Cytochemical MPO stain is a robust laboratory test that can be a valuable aid to morphology in early diagnosis of APML. In this study, the role of cytochemical MPO was evaluated for early diagnosis of APML.Method- This study included all the cases of APML that were diagnosed in a tertiary care center in India from May 2011 to May 2014. Cytochemical stains (MPO, Non- specific Esterase (NSE), Periodic- acid Schiff (PAS) stains were performed on peripheral smear and bone marrow aspirates. Flow cytometry was performed on peripheral blood/bone marrow aspirate in EDTA on Beckman Coulter Flow Cytometer (FC500) using a panel of markers. RT-PCR was not available. However, all the above cases responded immediately to trial of ATRA (diagnosis confirmed by response to treatment trial with ATRA). The study was approved by Institutional Ethics committee.Results & Discussion- 13 cases of APML (6 males, 7 females) were identified with age ranging from 2-36 years. On flow cytometry, side scatter was moderate in 4 cases and high in 9 cases. The former were AML M3v (hypogranular variant) whereas the latter were classic APML. CD13 was heterogeneously dim to moderate positive in 12/13 cases .CD 33 was homogenously positive in all 13 cases (dim positive in 3; moderate positive in 10). CD34 was positive in 1/13 case and HLA-DR was positive in 2/13cases. All cases showed 3+ cytochemical MPO positivity, diffuse flush PAS positivity and NSE positivity. All cases went into immediate remission on treatment with ATRA.Thus even though flow cytometry was helpful in diagnosing APML, there were still some variations in the patterns. It is concluded that, though flow cytometric pattern of APML is often characteristic, occasionally it may have moderate side scatter and positive HLA-DR and CD34. In such situations and also in places with limited availability of flow cytometry/ RT PCR , strong (3+) cytochemical MPO staining in addition to characteristic morphologic features helps in the quick suspicion of APML and early treatment trial with ATRA. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Small Molecule Activators of Protein Phosphatase 2A (SMAPs) Cause c-Myc Degradation and Tumor Growth Suppression in Preclinical Models of Lymphoid Malignancies

Introduction: c-myc is an oncogene implicated in the initiation and progression of multiple hematologic malignancies. Characteristic translocations of the c-myc gene with the immunoglobulin heavy chain gene (in Burkitt lymphoma and “double-hit” non-Hodgkin lymphoma) and with the T cell receptor gene (in T cell acute lymphoblastic leukemia, T-ALL) lead to constitutive expression of the c-myc transcription factor, ultimately driving dysregulated proliferation (Boxer & Dang, Oncogene 2001; 20(40):5595-5610). Strategies for inhibition of c-myc remain an area of active research; however, to date there are no approved myc-targeted agents within the cancer armamentarium, and cytotoxic chemotherapy remains the standard of care for c-myc-driven lymphoid malignancies. Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase tumor suppressor protein that contributes to c-myc degradation through both direct dephosphorylation of an identified phosphodegron as well as by indirect mechanisms (Farrell & Sears, Cold Spring Harbor Perspect Med 2014; 4(3):1-15). Our laboratory has developed a series of first in class, orally bioavailable small molecule activators of PP2A (SMAPs) by derivatizing tricyclic antipsychotics to maximize antiproliferative activity and minimize psychotropic properties (Sangodkar et al., J Clin Invest 2017;127(6):2081-2090). We hypothesized that activation of PP2A with SMAPs would lead to c-myc degradation and tumor growth inhibition in models of c-myc-driven lymphoid malignancies.Methods: We investigated the effects of SMAP treatment on c-myc content, c-myc half-life (t1/2), cell viability, and xenograft tumor growth in Burkitt lymphoma (BL) and T-ALL cell lines with wild type and mutant c-myc phosphodegrons.Results: SMAP treatment induced apoptosis in Daudi (BL) cells, as evidenced by decreased viability and increased PARP and caspase cleavage. In Daudi (BL) and CCRF-CEM (T-ALL) cell lines, SMAP treatment led to rapid loss of phosphorylated and total c-myc protein. Cycloheximide (CHX)-chase experiments performed in CCRF-CEM cells confirmed that SMAP treatment affects c-myc degradation without affecting protein synthesis. This effect was abrogated by Ser to Glu mutation of residue 62 within the c-myc phosphodegron, suggesting that SMAP-mediated c-myc degradation is PP2A-dependent. Treatment of NOD/SCID mice bearing Daudi xenografts with twice daily oral SMAP decreased tumor c-myc content and inhibited tumor growth without obvious toxicity. Xenografts overexpressing c-myc with phosphodegron mutations (S62D, T58I) were resistant to SMAP treatment.Conclusions: These in vitro and in vivo observations establish PP2A activation as a potential pharmacologic strategy to target c-myc in cancers such as BL, T-ALL, and “double hit” non-Hodgkin lymphoma. SMAPs are well-tolerated, orally bioavailable activators of PP2A poised for further exploration in the treatment of c-myc-driven malignancies, either alone or in combination with other agents. Sequencing of the c-myc phosphodegron prior to initiation of treatment may facilitate patient selection in future clinical trials of PP2A activators. [Display omitted] DisclosuresNarla:Mount Sinai School of Medicine: Patents & Royalties: patents on the small molecule PP2A activators (GN).

Leep1 interacts with PIP3 and the Scar/WAVE complex to regulate cell migration and macropinocytosis.

Polarity is essential for diverse functions in many cell types. Establishing polarity requires targeting a network of specific signaling and cytoskeleton molecules to different subregions of the cell, yet the full complement of polarity regulators and how their activities are integrated over space and time to form morphologically and functionally distinct domains remain to be uncovered. Here, by using the model system Dictyostelium and exploiting the characteristic chemoattractant-stimulated translocation of polarly distributed molecules, we developed a proteomic screening approach, through which we identified a leucine-rich repeat domain-containing protein we named Leep1 as a novel polarity regulator. We combined imaging, biochemical, and phenotypic analyses to demonstrate that Leep1 localizes selectively at the leading edge of cells by binding to PIP3, where it modulates pseudopod and macropinocytic cup dynamics by negatively regulating the Scar/WAVE complex. The spatiotemporal coordination of PIP3 signaling, Leep1, and the Scar/WAVE complex provides a cellular mechanism for organizing protrusive structures at the leading edge.

Intracranial non-myxoid angiomatoid fibrous histiocytoma with EWSR1-CREB1 transcript fusion treated with doxorubicin: A case report.

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor that has only been reported in the central nervous system in case reports. After surgery, patients exhibit tumor recurrence. Pathological diagnosis of AHF remains difficult, especially in sites other than skin. AFH can harbor characteristic translocations implying that the Ewing sarcoma breakpoint region 1 gene (EWSR1) fuses with the transcription factor cyclic AMP response element binding (CREB) family genes. Doxorubicin is a chemotherapy that has previously been used successfully in two metastatic soft tissue AFH cases but never in intracranial AFH. The present report describes a case of an adult with a progressive classical intracranial non-myxoid AFH with ESWR1-CREB1 transcript fusion 4 years after surgery. The patient was treated with doxorubicin as a single agent chemotherapy. This treatment resulted in a prolonged stable disease 15 months after treatment discontinuation. This is the first reported case of a treatment with doxorubicin in an adult with progressive intracranial AFH with ESWR1-CREB1 transcript fusion which was sustained after treatment discontinuation.

Clinical, Radiographic, Pathologic Characterization and Survival Outcomes of Nuclear Protein of the Testis Carcinoma.

Nuclear protein of the testis (NUT) carcinoma (formerly NUT midline carcinoma) is an aggressive tumor with characteristic BRD4-NUTM1 translocation and a poor prognosis. The primary objective of this study was to describe the clinical and radiologic features, treatment response, and survival of NUT carcinoma (NC). This retrospective single-center study was based on the review of medical records of NC patients with a specific genetic rearrangement or positive anti-NUT nuclear staining. Overall survival (OS) was analyzed according to primary tumor location. This series of 22 patients had a mean age of 36.27 ± 2.68 years with 68% women and 32% men. The median age at diagnosis was 34 years (range, 17-55 years). The primary tumor was located in the chest (n = 12/22; 55%), head and neck (n = 9/22; 40%), and 1 patient had a renal tumor. About 68% (n = 15/22) patients presented with regional lymph nodal involvement and 77% (n = 17/22) had distant metastases. All the bone metastases were lytic (100%) with mixed lytic and sclerotic metastases in 5 patients. Only 18% (n = 4/22) of the patients showed response to treatment, with progression in the remaining 18 patients. The median OS was 7 months. The OS was significantly (P = 0.024) more in patients with primary head and neck NC (n = 9; OS, 16 months) versus those with pulmonary and other locations (n = 13; OS, 6 months). Nuclear protein of the testis carcinoma is an aggressive disease refractory to conventional therapy. Imaging with the complementary use of computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography is important for staging, guiding management, assessing the treatment response, and surveillance.

Genetic drivers and cells of origin in sarcomagenesis.

Sarcoma comprises a group of malignancies that includes over 100 individual disease entities. Type-specific genetic events initiate each tumor, occurring within a specific cellular context or circumstance. All sarcomas share a relationship with mesenchymal tissues of origin. Conceptual models for each specific route towards sarcomagenesis have developed over the years as clinical, cellular, and increasingly molecular observations have advanced hypotheses to be tested in the forward or reverse direction in experimental systems, often genetically engineered model organisms. This review considers the history of these discoveries in the context of technologies available at the time each was made and provides a comprehensive summary of the current knowledge of sarcoma genetics, including characteristic translocations, oncogene activation and loss of tumor suppressor gene events, and their putative cells of origin. Also considered are the interrelatedness of molecular clinical observations and genetic experiments in model systems to move this field of knowledge forward, as well as their implications for diagnostic and therapeutic paradigms for sarcoma. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Establishment of PDX-derived salivary adenoid cystic carcinoma cell lines using organoid culture method.

To generate a reliable preclinical model system exhibiting the molecular features of salivary adenoid cystic carcinoma (ACC) whose biology is still unclear due to the paucity of stable cell cultures. To develop new in vitro and in vivo models of ACC, the techniques of organoid culture and patient-derived tumor xenograft (PDX), which have attracted attention in other malignancies in recent years, were applied. Tumor specimens from surgically resected salivary ACC were proceeded for the preparation of PDX and organoid culture. The orthotopic transplantation of patient-derived or PDX-derived organoids was demonstrated into submandibular glands of NSG mice and those histology was evaluated. PDX-derived organoid cells were evaluated for the presence of MYB-mediated fusion genes and proceeded for in vitro drug sensitivity assay. Human ACC-derived organoids were successfully generated in three-dimensional culture and confirmed the ability of these cells to form tumors by orthotopic injection. Short-term organoid cell cultures from two individual ACC PDX tumors were also established that maintain the characteristic MYBL1 translocation and histological features of the original parent and PDX tumors. Finally, the establishment of drug sensitivity tests on these short-term cultured cells was confirmed using three different agents. This is the first to report an approach for the generation of human ACC-derived organoids as in vitro and in vivo cancer models, providing insights into understanding of the ACC biology and creating personalized therapy design for patients with ACC.

Synovial Sarcoma: A Complex Disease with Multifaceted Signaling and Epigenetic Landscapes.

Aside from a characteristic SS18-SSX translocation identified in almost all cases, no genetic anomalies have been reliably isolated yet to drive the pathogenesis of synovial sarcoma. In the following review, we explore the structural units of wild-type SS18 and SSX, particularly as they relate to the transcriptional alterations and cellular pathway changes imposed by SS18-SSX. Native SS18 and SSX contribute recognizable domains to the SS18-SSX chimeric proteins, which inflict transcriptional and epigenetic changes through selective protein interactions involving the SWI/SNF and Polycomb chromatin remodeling complexes. Multiple oncogenic and developmental pathways become altered, collectively reprogramming the cellular origin of synovial sarcoma and promoting its malignant transformation. Synovial sarcoma is characterized by complex epigenetic and signaling landscapes. Identifying the operational pathways and concomitant genetic changes induced by SS18-SSX fusions could help develop tailored therapeutic strategies to ultimately improve disease control and patient survivorship.

FROM BONE TO BRONCHUS: HIP OSTEOSARCOMA WITH LUNG METASTASIS

SESSION TITLE: Fellows Lung Cancer Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: A 44-year-old male with past medical history of left hip osteosarcoma status post resection in 2017 presented with cough and shortness of breath. CASE PRESENTATION: Chest x-ray revealed extensive cannonball type appearing bilateral lung involvement which was confirmed by CT angiography as being concerning for metastasis. This was confirmed by lung biopsy as pulmonary metastasis of his hip osteosarcoma. DISCUSSION: Osteosarcoma is a relatively uncommon tumor in adults with an incidence of roughly 500 new cases per year in the US. 10 to 20 percent present with a metastatic process with the lung being the most common site. Several risk factors have been identified including prior radiation or chemotherapy in childhood, Paget’s, fibrous dysplasia, chronic osteomyelitis as well as inherited conditions such as retinoblastoma, Li-Fraumeni and Rothmund-Thomson syndrome. Noteworthy of osteosarcoma is the lack of characteristic translocations or identifiable genetic abnormalities, unlike other types of sarcomas. CONCLUSIONS: Extensive staging workup is crucial for these patients as those with metastatic disease have a significantly worse outcome but half of cases with limited pulmonary involvement are amenable to cure. CT is the current gold standard for evaluation of metastatic disease in the thorax although a recent study demonstrated that more than one third of pulmonary mets would be missed unless an open thoracotomy was done with manual palpation of the lung. This further necessitates the importance of close monitoring as well as a multi-faceted approach with chemo and metastectomy which could significantly extend survival times. Reference #1: “The metastatic patterns of osteosarcoma”. Jeffree GM, Price CH, Sissons HA. Br J Cancer. 1975;32(1):87. Reference #2: “Current treatment of osteosarcoma”. Ferguson WS, Goorin AM. Cancer Invest. 2001;19(3):292. Reference #3: “Osteosarcoma over the age of forty”. Grimer RJ, Cannon SR, Taminiau AM, Bielack S, Kempf-Bielack B, Windhager R, Dominkus M, Saeter G, Bauer H, Meller I, Szendroi M, Folleras G, San-Julian M, van der Eijken J. Eur J Cancer. 2003;39(2):157. DISCLOSURES: no disclosure on file for Mohammad Al-Ameri; No relevant relationships by Raashi Chawla, source=Web Response No relevant relationships by Daymon Peterson, source=Web Response No relevant relationships by Tanaz Salimnia, source=Web Response

Frequency of Translocation t(11;22)(q24;q12) Using Fluorescence In Situ Hybridization (FISH) in Histologically and Immunohistochemically Diagnosed Cases of Ewing's Sarcoma.

IntroductionEwing sarcoma (ES) family of tumors is one of the most common groups of malignancies arising in children, adolescents, and young adults. Although characteristic histology with immunohistochemical expression of CD99 and FLI1 after exclusion of other small round blue cell tumors is considered diagnostic of ES, frequency of typical ES translocation, i.e., t(11;22)(q24;q12) is not known in our population. Therefore, in this study, we aimed to evaluate the frequency of this translocation in histologically and immunohistochemically diagnosed cases of ES along with its association with other pathological parameters.MethodsA total of 43 morphologically and immunohistochemically diagnosed cases of ES were included in the study. Fluorescence in situ hybridization (FISH) was performed on representative paraffin blocks to identify t(11;22)(q24;q12) translocation. Association with various clinicopathological characteristics was determined.ResultsMean age of the patients was 18.23±9.57 years. Bone was the most commonly involved site (22; 51.2%) followed by soft tissue (17; 39.5%) and parenchymal organs (4; 9.3%). A total of 88.4% of cases were found to be FISH-positive for t(11;22)(q24;q12). No significant association of translocation positive cases was noted with tumor size or disease-free survival. Similarly, no significant association of tumor size with disease-free survival was found.ConclusionsA significant proportion of cases of histologically diagnosed cases of ES exhibited characteristic t(11;22)(q24;q12). This signifies that histology along with immunohistochemistry is reliable for the diagnosis of this tumor; however, in difficult cases, FISH can be performed to detect characteristic translocation. Moreover, we did not find tumor size to be a significant prognostic indicator of survival in ES.

SECRETORY CARCINOMA OF THE PAROTID: APPROACH WITH MORPHOLOGY, CYTO-IMMUNOHISTOCHEMISTRY, AND FLUORESCENCE IN SITU HYBRIDIZATION ANALYSIS OF THE RARE ENTITY

Mammary analog secretory carcinoma (MASC) is a recently described entity listed in the World Health Organization classification of the salivary gland tumors under the head and neck tumors. It is a low-grade malignancy with a relatively benign course. The identification of this new but less recognized entity is warranted due to a limited understanding of the prevalence, clinical course, behavior, and prognosis. Here, we present a case of MASC arising in the right parotid gland in a 50-year-old gentleman. It was slow-growing swelling associated with the recent onset of pain. On examination, 4×3 cm swelling was present just below the right ear lobule. It was firm, irregular in shape with a smooth surface with slight mobility to the overlying skin. Fine-needle aspiration cytology suggested differentials of salivary duct carcinoma, acinic cell carcinoma, mucoepidermoid carcinoma, and metastatic carcinoma. The patient underwent right superficial parotidectomy with supraomohyoid neck dissection, and histopathology came out to be secretory analog mammary carcinoma. Immunohistochemistry is a confirmatory test that shows positivity for S-100 protein and mammaglobin and shows characteristic ETV6-NTRK3 translocation.

Conjunctival Adenosquamous Carcinoma Lacks MAML2 Translocation: A Variant of Squamous Cell Carcinoma With Mucoepidermoid Differentiation and Aggressive Behavior?

Conjunctival adenosquamous carcinoma, also known as mucoepidermoid carcinoma (MEC), is a rare tumor that preferentially affects the perilimbal area of the conjunctiva with aggressive local invasion. Consisting of infiltrative proliferation of squamous cells and mucous cells, its morphologic features are reminiscent of the salivary gland-type MEC except for the absence of intermediate cells and frequent keratin production. We reported 2 cases of conjunctival adenosquamous carcinoma and, for the first time, studied the MAML2 translocation status of this rare entity. The 2 patients were women, aged 45 and 42 years, presenting with an erythematous lesion in the left lower palpebral conjunctiva and a pigmented nodule over the left nasal conjunctiva, respectively. One tumor recurred 6 months after the initial biopsy. Excision with lid reconstruction and postoperative radiotherapy was performed for margin involvement and perineural invasion. This patient was disease free at 3-year follow-up. The other patient was lost to follow-up after tumor excision. Fluorescence in situ hybridization and reverse transcription polymerase chain reaction failed to demonstrate MAML2 translocation and CRCT1-MAML2 transcripts in both tumors. The absence of this characteristic translocation and reappraisal of the cellular composition, morphologic features, and precursor lesion suggest that conjunctival MEC may represent a variant of conjunctival squamous cell carcinoma but not related to the salivary gland-type MEC.

A Case of Secretory Carcinoma of the Soft Palate

Secretory carcinoma of salivary gland origin is a recently described tumor that harbors a characteristic ETV6-NTRK3 translocation that is identical to secretory carcinoma of the breast. The majority of tumors were located in the parotid gland and other major salivary glands, while the minority occurred in a minor salivary gland. We present a case of a 71-year-old female who was diagnosed with low-grade salivary gland cancer presenting in the soft palate accompanying lymph node metastasis. Peroral wide excision, selective neck dissection, reconstruction with radial forearm free flap was performed. The final pathology report indicated secretory carcinoma of the soft palate. The patient was followed-up without evidence of recurrence for one year. At present, it is difficult to accurately assess prognosis and treatment for the secretory carcinoma of the minor salivary gland origin. Continuous follow-up with various cases is needed further. Key Words: Secretory carcinoma, Salivary gland tumor, Minor salivary gland, Soft palate

Outer Radial Glia-like Cancer Stem Cells Contribute to Heterogeneity of Glioblastoma.

Glioblastoma is a devastating form of brain cancer. To identify aspects of tumor heterogeneity that may illuminate drivers of tumor invasion, we created a glioblastoma tumor cell atlas with single-cell transcriptomics of cancer cells mapped onto a reference framework of the developing and adult human brain. We find that multiple GSC subtypes exist within a single tumor. Within these GSCs, we identify an invasive cell population similar to outer radial glia (oRG), a fetal cell typethat expands the stem cell niche in normal human cortex. Using live time-lapse imaging of primary resected tumors, we discover that tumor-derived oRG-like cells undergo characteristic mitotic somal translocation behavior previously only observed inhuman development, suggesting areactivation ofdevelopmental programs. In addition, we showthat PTPRZ1 mediates both mitotic somal translocation and glioblastoma tumor invasion. These data suggest that the presence of heterogeneous GSCs may underlie glioblastoma's rapid progression and invasion.