Técnicas de citogenética para el estudio de las leucemias / Cytogenetic techniques for the study of leukemias

Introducción: La leucemia se define como un proceso clonal de células hematopoyéticas, que se origina cuando las células sanguíneas que se producen en la médula ósea, cambian y se multiplican sin control. Esta se caracteriza por su heterogeneidad genética y se explica a través de mecanismos causados por alteraciones cromosómicas utilizados en la práctica clínica diaria como biomarcadores útiles para el diagnóstico, el pronóstico o la predicción de respuesta al tratamiento. Objetivo: Describir las técnicas de citogenética convencional y molecular para el diagnóstico y seguimiento de las leucemias. Métodos: Se realizó una revisión de la literatura en inglés y español, a través del sitio web PubMed y el motor de búsqueda Google Académico, de artículos publicados en los últimos cinco años. Se hizo un análisis y resumen de la bibliografía revisada. Análisis y síntesis de la información: En el transcurso de los años la citogenética ha proporcionado información crucial para el diagnóstico y el pronóstico de las neoplasias hematológicas. Tanto las técnicas de citogenética convencional y molecular, como la hibridación in situ fluorescente, la hibridación in situ fluorescente multicolor, el cariotipo espectral, la hibridación genómica comparada y los microarreglos, participan en el reconocimiento de alteraciones cromosómicas y de genes, así como de interacciones involucradas en el proceso de oncogénesis. Conclusiones: Las técnicas de citogenética contribuyen al diagnóstico, a la estratificación pronóstica y a la aplicación del tratamiento según el tipo o subtipo de leucemia(AU)

Introduction: Leukemia is defined as a clonal process of hematopoietic cells, which occurs when blood cells that are produced in the bone marrow change and multiply uncontrollably. This is characterized by its genetic heterogeneity and is explained through mechanisms caused by chromosomal alterations that are used in daily clinical practice as useful biomarkers for diagnosis, prognosis or prediction of response to treatment. Objective: To describe the conventional and molecular cytogenetic techniques used for the diagnosis and monitoring of leukemias. Methods: A review of the literature in English and in Spanish was carried out, in the PubMed website and using the search engine Google, for articles published in the last five years. We performed analysis and summary of the reviewed bibliography. Analysis and synthesis of information: Cytogenetics over the years has provided crucial information for the diagnosis and prognosis of hematologic malignancies. Both conventional and molecular cytogenetic techniques such as fluorescent in situ hybridization, multicolor fluorescent in situ hybridization, spectral karyotype, comparative genomic hybridization and microarrays, participate in the recognition of chromosomal and gene alterations, as well as interactions involved in the oncogenesis process. Conclusions: These cytogenetic techniques contribute to the diagnosis, prognostic stratification and application of treatment according to the type or subtype of leukemia(AU)

Frecuencia de discapacidad intelectual de etiología genética debida a rearreglos cromosómicos crípticos / Frequency of intellectual disability of genetic etiology due to cryptic chromosome arrangements

Introducción: la discapacidad intelectual se considera un problema de salud pública global, la prevalencia oscila entre el 1% al 3% de la población mundial, cifra de la que se estima el origen genético estaría representado por el 5-7% de síndromes subteloméricos. El objetivo de la presente investigación fue determinar la frecuencia de discapacidad intelectual de etiología genética debida a rearreglos cromosómicos crípticos en 69 pacientes del IDAI. Material y Métodos. El estudio descriptivo de corte transversal se realizó en el Instituto de Genética en 69 pacientes con discapacidad intelectual de 5 a 18 años del Instituto de Adaptación Infantil (IDAI). El estudio fue dividido en tres etapas, la primera consistió en la elaboración de la historia clínica genética, seguidamente, se realizó el estudio de cariotipo en sangre periférica a todos los pacientes, finalmente, con la sospecha diagnóstica se realizó citogenética molecular a nueve de ellos, empleando una sonda locus específica. Resultados. Se encontró 43.48% de rearreglos cromosómicos, 24.67% correspondió a síndromes crípticos, de estos el 7.25% respondió a síndromes subteloméricos. Se observó mayor afectación en la población masculina: 45 hombres (65%) y 24 mujeres (35%), obteniendo una razón de sexo de 1.88 a favor del sexo masculino. Conclusiones. Se debe considerar la causa genética en toda discapacidad intelectual idiopática, sobre todo la debida a rearreglos cromosómicos crípticos . Para confirmar la sospecha diagnóstica se emplean técnicas de citogenética clásica y de hibridación fluorescente in situ , de esta manera se llega a un diagnóstico más preciso para coadyuvar en el asesoramiento genético del paciente.

Introduction. Intellectual disability is considered a global public health problem, the prevalence ranges from 1% to 3% of the world population, a figure whose genetic origin is estimated to be represented by 5-7% of subtelomeric syndromes. The objective of this research was to determine the frequency of intellectual disability of genetic etiology due to cryptic chromosomal rearrangements in 69 patients of IDAI. Material and methods. The descriptive cross-sectional study was carried out at the Institute of Genetics in 69 patients with intellectual disabilities from 5 to 18 years of age from the Institute for Child Adaptation (IDAI). The study was divided into three stages, the first consisted of preparing the genetic clinical history, then peripheral blood karyotyping was performed on all patients, finally, with suspected diagnosis, molecular cytogenetics was performed on nine of them, using a locus-specific probe. Results. 43.48% of chromosomal rearrangements were found, 24.67% corresponded to cryptic syndromes, of these 7.25% responded to subtelomeric syndromes. Greater involvement was observed in the male population: 45 men (65%) and 24 women (35%), obtaining a sex ratio of 1.88 in favor of the male sex. Conclusions. The genetic cause must be considered in all idiopathic intellectual disability, especially that due to cryptic chromosomal rearrangements. To confirm the diagnostic suspicion, classical cytogenetics and fluorescent in situ hybridization techniques are used, thus reaching a more precise diagnosis to assist in the genetic counseling of the patient.

LncRNA-m18as1 competitively binds with miR-18a-5p to regulate follicle-stimulating hormone secretion through the Smad2/3 pathway in rat primary pituitary cells / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Long noncoding RNAs (lncRNAs) are expressed in different species and different tissues, and perform different functions, but little is known about their involvement in the synthesis or secretion of follicle-stimulating hormone (FSH). In general, we have revealed lncRNA‍‒‍microRNA (miRNA)‍‒‍‍messenger RNA (mRNA) interactions that may play important roles in rat primary pituitary cells. In this study, a new lncRNA was identified for the first time. First, we analyzed the gene expression of lncRNA-m18as1 in different tissues and different stages by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and observed the localization of lncRNA-m18as1 with fluorescence in situ hybridization, which indicated that this lncRNA was distributed mainly in the cytoplasm. Next, we used RT-qPCR and enzyme-linked immunosorbent assay (ELISA) to analyze the regulation of FSH synthesis and secretion after overexpression or knockdown of lncRNA-m18as1 and found that lncRNA-m18as1 was positively correlated with FSH synthesis and secretion. In addition, mothers against decapentaplegic homolog 2 (Smad2) was highly expressed in our sequencing results. We also screened miR-18a-5p from our sequencing results as a miRNA that may bind to lncRNA-m18as1 and Smad2. We used RNA immunoprecipitation-qPCR (RIP-qPCR) and/or dual luciferase assays to confirm that lncRNA-m18as1 interacted with miR-18a-5p and miR-18a-5p interacted with Smad2. Fluorescence in situ hybridization (FISH) showed that lncRNA-m18as1 and miR-18a-5p were localized mainly in the cytoplasm. Finally, we determined the relationship among lncRNA-m18as1, miR-18a-5p, and the Smad2/3 pathway. Overall, we found that lncRNA-m18as1 acts as a molecular sponge of miR-18a-5p to regulate the synthesis and secretion of FSH through the Smad2/3 pathway.

Caracterización clínica y citogenética de una cohorte de pacientes con leucemia promielocítica aguda atendidos en un Hospital Universitario en Medellín, Colombia / Clinical and cytogenetic characterization of a cohort of patients with acute promyelocytic leukemia treated at a University Hospital in Medellín, Colombia

Introducción. La leucemia promielocítica aguda (LPA) es un subtipo poco frecuente de leucemia mieloide aguda (LMA), que se caracteriza por un comportamiento clínico particularmente agresivo, y en ausencia de tratamiento, su curso generalmente es fatal. El objetivo de este trabajo fue determinar las características clínicas y citogenéticas de una cohorte de pacientes con LPA, con la finalidad de evaluar su relación con las complicaciones, el pronóstico y el desenlace de estos pacientes. Metodología. Se realizó un estudio observacional, descriptivo, retrospectivo de los pacientes mayores de 15 años con diagnóstico de LPA, atendidos en el Hospital Universitario San Vicente Fundación, entre los años 2012 a 2020. Resultados. Un total de 32 pacientes fueron incluidos. La edad media del diagnóstico fue 37 años. El 84,4% de los pacientes tenía la traslocación (15;17) en el cariotipo, y el 93,75% tenían FISH positivo. El 12,5% de los casos tenían cariotipo complejo. La mortalidad en los primeros 30 días fue del 15,6%, siendo el sangrado la causa de muerte más frecuente. Todos los pacientes que sobrevivieron alcanzaron la remisión completa (84,3%). En un promedio de seguimiento de 24 meses, el 14,8% de los casos recayeron. En el análisis bivariado se encontró relación entre sexo masculino y tener cariotipo complejo (p=0,015). No se encontró relación entre cariotipo complejo y mortalidad temprana (p=0,358), tampoco entre cariotipo complejo y recaída (p=0,052). Conclusiones. Se presentan las características clínicas y citogenéticas de una cohorte de pacientes con LPA en Colombia. El sangrado en el sistema nervioso central fue la principal causa de mortalidad temprana, todos los pacientes que sobrevivieron alcanzaron la remisión completa con la terapia de inducción. Las tasas de mortalidad, remisión completa y recaída fueron similares a las reportadas por otras series latinoamericanas, pero inferiores a estudios provenientes de países europeos. Contrario a lo reportado en otros estudios, no se encontró relación entre el cariotipo complejo y la mortalidad temprana o recaída.

Introduction. Acute promyelocytic leukemia (APL) is a rare subtype of acute myeloid leukemia (AML), characterized by a particularly aggressive clinical behavior, that in the absence of treatment is usually fatal. The objective of this work was to determine the clinical and cytogenetic characteristics of a cohort of patients with APL, in order to evaluate their relationship with the outcome and prognosis of these patients. Methodology. An observational, descriptive, retrospective study of patients older than 15 years with a diagnosis of APL treated at the Hospital Universitario San Vicente Fundación, between 2012 and 2020, was carried out. Results. A total of 32 patients were included. The mean age at diagnosis was 37 years, 84.4% of the patients had the t(15;17) in the karyotype, and 93.75% had positive FISH. 12.5% of cases had a complex karyotype. Mortality in the first 30 days was 15.6%, with bleeding being the most common cause of death. All patients who survived achieved complete remission (84.3%). In an average follow-up of 24 months, 14.8% of cases relapsed. In the bivariate analysis, a relationship was found between the male sex and having a complex karyotype (p<0.015). No relationship was found between complex karyotype and early mortality (p=0.358), nor between complex karyotype and relapse (p=0.052). Conclusions. We present the clinical and cytogenetic characteristics of a cohort of patients with APL in Colombia. Central nervous system bleeding was the main cause of early mortality, with all surviving patients achieving complete remission on induction therapy. Mortality, complete remission and relapse rates were similar to those reported by other Latin American series, but lower than studies from European countries. Contrary to what has been reported in other studies, no relationship was found between complex karyotype and early mortality or relapse

Influence of the number of high-risk cytogenetic abnormalities on the clinical characteristics and prognosis in 360 patients with newly diagnosed multiple myeloma / 中华血液学杂志

Objective: To investigate the influence of the number of high-risk cytogenetic abnormalities (HRCA) on the clinical characteristics and prognosis of patients with newly diagnosed multiple myeloma (MM) . Methods: A total of 360 patients with newly diagnosed MM admitted to Jiangsu Province Hospital between November 2013 and September 2020 were included in this study. Cytoplasmic light chain immunofluorescence with fluorescence in situ hybridization (cIg-FISH) was used to detect HRCA. Cytogenetic abnormalities were combined with clinical characteristics and outcomes for further analysis. Results: Among the 360 patients, 120 patients (33.3%) presented with no HRCAs, and 175 (48.6%) , 61 (16.9%) , and four (1.1%) patients had one, two, and three HRCA (s) , respectively. Patients were divided into three groups, including the no-HRCA group, one-HRCA group, and ≥two-HRCA group, according to the number of HRCAs. There were significant differences in the R-ISS stage, hemoglobin level, albumin level, and the proportion of bone marrow plasma cells among the three groups (P<0.05) . The COX proportional-hazards model identified extramedullary disease (P=0.018) , HRCA ≥ 2 (P=0.001) , and absence of autologous hematopoietic stem cell transplantation (P<0.001) as independent risk factors for progression free survival (PFS) and identified lactate dehydrogenase (LDH) level ≥ 220 U/L (P<0.001) , HRCA ≥2 (P=0.001) , and absence of autologous hematopoietic stem cell transplantation (P=0.005) as independent risk factors for overall survival (OS) . The median PFS was 28 months, 22 months, and 14 months (P=0.005) for the three cohorts, and their OS was not reached,60 months, and 30 months (P=0.001) , respectively. Conclusions: HRCA ≥ 2 is an independent risk factor for decreased survival in patients with newly diagnosed MM. More HRCAs result in heavier tumor burden, as well as a higher risk of disease progression and death.

Gene Mutation and Overexpression of Newly Diagnosed Multiple Myeloma Patients / 中国实验血液学杂志

OBJECTIVE@#To analyze the characteristics of gene mutation and overexpression in newly diagnosed multiple myeloma (NDMM) patients.@*METHODS@#Bone marrow cells from 208 NDMM patients were collected and analyzed. The gene mutation of 28 genes and overexpression of 6 genes was detected by DNA sequencing. Chromosome structure abnormalities were detected by fluorescence in situ hybridization (FISH).@*RESULTS@#Gene mutations were detected in 61 (29.33%) NDMM patients. Some mutations occurred in 5 or more cases, such as NRAS, PRDM1, FAM46C, MYC, CCND1, LTB, DIS3, KRAS, and CRBN. Overexpression of six genes (CCND1, CCND3, BCL-2, CCND2, FGFR3, and MYC) were detected in 83 (39.9%) patients, and cell cycle regulation gene was the most common. Single nucleotide polymorphisms (SNP) changes were detected in 169 (81.25%) patients, the TP53 P72R gene SNP (70.17%) was the most common. Abnormality in chromosome structure was correlated to gene overexpression. Compared to the patients with normal chromosome structure, patients with 14q32 deletion showed higher proportion of CCND1 overexpression. Similarly, patients with 13q14 deletion showed higher proportion of FGFR3 overexpression, whereas patients with 1q21 amplification showed higher proportion of CCND2, BCL-2 and FGFR3 overexpression.@*CONCLUSION@#There are multiple gene mutations and overexpression in NDMM. However, there is no dominated single mutation or overexpression of genes. The most common gene mutations are those in the RAS/MAPK pathway and the genes of cyclin family CCND are overexpression.

Polymerase chain reaction-based assays facilitate the breeding and study of mouse models of Klinefelter syndrome / 亚洲男科学杂志(英文版)

Klinefelter syndrome (KS) is one of the most frequent genetic abnormalities and the leading genetic cause of nonobstructive azoospermia. The breeding and study of KS mouse models are essential to advancing our knowledge of the underlying pathological mechanism. Karyotyping and fluorescence in situ hybridization are reliable methods for identifying chromosomal contents. However, technical issues associated with these methods can decrease the efficiency of breeding KS mouse models and limit studies that require rapid identification of target mice. To overcome these limitations, we developed three polymerase chain reaction-based assays to measure specific genetic information, including presence or absence of the sex determining region of chromosome Y (Sry), copy number of amelogenin, X-linked (Amelx), and inactive X specific transcripts (Xist) levels. Through a combined analysis of the assay results, we can infer the karyotype of target mice. We confirmed the utility of our assays with the successful generation of KS mouse models. Our assays are rapid, inexpensive, high capacity, easy to perform, and only require small sample amounts. Therefore, they facilitate the breeding and study of KS mouse models and help advance our knowledge of the pathological mechanism underlying KS.

Clinical genetic analysis of an infant with 1q21.3-qter duplication and Xpter-p11 deletion caused by maternal balanced chromosomal translocation / 中华医学遗传学杂志

OBJECTIVE@#To investigate the clinical phenotype and genetic diagnosis of an infant featuring multiple hair and hyperbilirubinemia.@*METHODS@#Conventional G-banding analysis, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the patient were conducted, G-banding analyses of peripheral blood for the infant's parents were also performed.@*RESULTS@#We investigated an infant who carries a unbalanced, maternally inherited karyotype 46, X, der (X) t (X;1) (p11.22; q21.3) in which CMA and FISH analyses disclosed a 1q21.3q44 duplication of 93.03 Mb and Xp22.33p11.22 deletion of 54.53 Mb.@*CONCLUSION@#The phenotypes of this infant can probably be attributed to the 1q21.3q44 duplication and Xp22.33p11.22 deletion, which were maternally inherited.

Genetic analysis of a case with mosaicism of a small supernumerary marker chromosome derived from idic(15) / 中华医学遗传学杂志

OBJECTIVE@#To determine the origin of a mosaicism small supernumerary marker chromosome (sSMC) by cytogenetic and molecular analysis.@*METHODS@#Karyotype analysis, fluorescence in situ hybridization (FISH) and SNP-array were carried out.@*RESULTS@#The karyotype of the patient was mos47,XX,+mar[45]/48,XX,+2mar[3]/46,XX[52]; the SNP-array result was arr[hg19]15q11.1q11.2 (20 161 372-24 314 675)×3, and the repeat fragment was about 4.15 Mb. FISH showed that approximately 50% of the cells have contained a sSMC with double D15Z1 probe site segments derived from abnormal idic(15). This sSMC did not contain SNRPN and PML probe fragments of Prader-Willi syndrome/Angelman syndrome.@*CONCLUSION@#When the patient's karyotype and phenotype are inconsistent, cytogenetic and molecular biology technologies should be combined to clarify the karyotype and gene location, so as to provide more accurate genetic consultation for the follow-up treatments.

Genetic analysis of a case with 2q37 microdeletion syndrome / 中华医学遗传学杂志

OBJECTIVE@#To diagnose and fine map a deletion in chromosome region 2q37.@*METHODS@#G-banded chromosomal karyotyping, multiplex ligation-dependent probe amplification (MLPA), single nucleotide polymorphism array (SNP-array), and fluorescence in situ hybridization (FISH) were carried out in conjunct for the analysis.@*RESULTS@#The patient was found to have karyotype of 46,XY,del(2)(q3?), MLPA revealed one copy number of both CAPN10-3 and ATG4B-7 genes from the 2q37.3 region, Both parents were found to be normal upon chromosome karyotyping and MLPA. SNP-array has found a 9.7 Mb deletion in the 2q37.1.37.3 region. FISH analysis has confirmed there is a single copy for 2q37.3.@*CONCLUSION@#Combination of MLPA, FISH and SNP-array have enabled accurate diagnosis for the patient, and also provided more clues for the correlation of genotype with the phenotype of the disease, and a basis for genetic counseling.

Genetic analysis of a fetus with mosaicism of 13q inversion duplication / 中华医学遗传学杂志

OBJECTIVE@#To report on a case of mosaicism 13q inversion duplication, analyze its mechanism, and discuss the correlation between its genotype and phenotype.@*METHODS@#Amniotic fluid and umbilical cord blood were collected at 23 and 32 weeks of gestation, respectively. Combined with G-banding chromosome karyotyping analysis, single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) were used to confirm the result.@*RESULTS@#The karyotype of the fetus was determined as 47,XY,+inv dup(13)(q14.3q34)/46,XY. After careful counseling, the couple decided to continue with the pregnancy, and had given birth to a boy at 40 weeks' gestation. Except for a red plaque (hemangioma) on the nose bridge, no obvious abnormality (intelligence to be evaluated) was discovered.@*CONCLUSION@#To provide reference for clinical genetic counseling and risk assessment, the location and proportion of new centromere formation should be fully considered in the case of mosaicism 13q inversion duplication.

Application of Flow Cytometry Combined Fluorescence in Situ Hybridization to Indentify the Lymphocyte Subtypies with Epstein-Barr Virus Infection / 中国实验血液学杂志

OBJECTIVE@#To establish the technique that take the advantages of flow cytometry combined fluorescence in situ hybridization (Flow-FISH) to identify the Epstein-Barr virus(EBV) infected lymphocyte subtypies in patients' peripheral blood sample.@*METHODS@#Peripheral Blood monocyte from 9 patients with EBV infection enrolled at Children's Hospital in Chongqing Medical University were isolated by Ficoll-paque centrifugal separation. The expressions of EBER1, EBER2 in cell were detected by qRT-PCR. The surface markers of cell were detected by Flow cytometry after staining with their antibodies. The cell was treated Fix-Permeabilization Buffer before hybridization with fluorescent labeled probe at 37 ℃ overnight. The cell status, surface markers and targeted mRNA are detected by flow cytometry and fluorescence microscope.@*RESULTS@#It was optimized that the Fix-Permeabilization Buffer and recipe with 0.2% Tween-20 were picked out as providing a good cell integrity and high resolution of surface markers. Hybridization with 20% formamide and 7% dextran sulfate at 37 ℃ overnight is the optimal hybridization condition as a good hybridization effect, a detectable cell integrity and a high resolution of cell markers under flow cytometry detection. Finally, upon the established Flow-FISH method, lymphocyte subpopulations of the EBV+ cells from cell lines and blood samples of patients were identified successfully.@*CONCLUSION@#A Flow-FISH technology is established, which can be applied in the identification of EBV infected cell subtypes. This research provides a foundmental for its application in clinical test in EBV+ related proliferative diseases.

Clinicopathological and molecular genetic features of cyclin D1-negative mantle cell lymphoma / 中华病理学杂志

Objective: To investigate the clinicopathological features and molecular genetics of cyclin D1-negative mantle cell lymphoma (MCL). Methods: The clinicopathological features and molecular genetics of CyclinD1-negative MCL diagnosed between January 2016 and July 2021 at the First Affiliated Hospital of Zhengzhou University were analyzed using immunohistochemistry and fluorescence in situ hybridization. Clinical information was collected and analyzed. Results: A total of five Cyclin D1-negative MCL cases from all 212 MCL patients (5/212, 2.4%)were included. There were three male and two female patients,age ranged from 59 to 70 years (median 64 years). All patients presented with nodal lesions. None of the patients had B symptoms but four had bone marrow involvement. Histopathologically, four cases were classic MCL and one case was pleomorphic variant type. All five cases were negative for Cyclin D1 but SOX-11 were positive in all cases. CD5 was positive in four cases and one case was weakly positive for CD23. CD10 and bcl-6 were negative in all cases. CCND1 translocation was identified in three cases and CCND2 translocation in one case by FISH analysis. However,CCND3 translocations were not found in the five cases. Conclusions: Cyclin D1-negative MCL are uncommon, its accurate diagnosis needs combined analysis with morphologic and immunophenotypic characteristics and genetic changes. It may be particularly difficult to distinguish from other small cell type B cell lymphomas. FISH analyses for CCND1/CCND2/CCND3 translocations and immunohistochemistry for SOX-11 are helpful to resolve such a difficult distinction.

Diagnostic value of MDM2 RNA in situ hybridization in atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma / 中华病理学杂志

Objective: To investigate the value of MDM2 RNA in situ hybridization (RNA-ISH) in diagnosing atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) and dedifferentiated liposarcoma (DDL). Methods: A total of 26 ALT/WDL/DDLs diagnosed from March 2017 to May 2019 in West China Hospital, Sichuan University, Chengdu, China and 18 control cases were included. MDM2 RNA-ISH was performed on all samples and compared with the fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) regarding their performance in detecting MDM2. Results: All samples were detected successfully using the three methods. Among 26 ALT/WDL/DDLs, all cases showed MDM2 amplification and positivity for MDM2 RNA-ISH (26/26, 100%). Twenty-four (24/26, 92.3%) of the 26 tested cases were positive for MDM2 IHC while two of them were negative. Eighteen control cases were all negative for MDM2 FISH and RNA-ISH, and 15 (15/18) cases were negative for MDM2 IHC. The sensitivity and specificity of RNA-ISH were both 100%, and those of MDM2 IHC were 92.3% and 83.3%, respectively. Diffuse staining was identified in all MDM2 RNA-ISH positive ALT/WDL/DDLs, but identified in only 8/24 (33.3%) of the MDM2 IHC positive cases. Among the 11 ALT/WDL/DDL samples evaluated on tissue microarray, the positive rate of MDM2 RNA-ISH was 100% with diffuse staining in all cases. The positive rate of MDM2 IHC was 9/11 while only 1 of the 9 cases showed diffuse staining. The result of MDM2 RNA-ISH was identical to that of MDM2 FISH and was overall consistent with that of MDM2 IHC (Kappa=0.763, P<0.001). Conclusions: In ALT/WDL/DDLs, results of MDM2 RNA-ISH are highly consistent with those of FISH. MDM2 RNA-ISH is more sensitive and more specific and has more diffuse positive signals than the IHC. The findings indicate that MDM2 RNA-ISH is highly valuable for the diagnosis and differential diagnosis of ALT/WDL/DDLs.

Clinicopathological features of NTRK3 gene rearrangement papillary thyroid carcinoma / 中华病理学杂志

Objective: To investigate the clinicopathological features and differential diagnosis of NTRK3 gene rearrangement thyroid papillary carcinoma (PTC). Methods: The PTC cases without BRAF V600E mutation were collected at Fujian Provincial Hospital South Branch from January 2015 to January 2020. The cases of NTRK3 gene rearrangement PTC were examined using immunohistochemistry and fluorescence in situ hybridization (FISH). The clinical data, histopathological characteristics, immunohistochemical features and molecular pathological changes were retrospectively analyzed. Data from the TCGA PTC dataset and the literature were also studied. Results: A total of 3 PTC cases harboring NTRK3 gene rearrangement were confirmed. All the patients were female, aged from 26,49,34 years. Histologically, two of them demonstrated a multinodular growth pattern. Only one case showed prominent follicular growth pattern; the other two tumors showed a mixture of follicular, papillary and solid growth patterns. All tumors showed a typical PTC nuclear manifestation, with some nuclear pleomorphism, vacuolated foci and oncocytic features. The characteristic formation of glomeruloid follicular foci was present in two cases which also showed psammoma bodies, and tumoral capsular or angiolymphatic invasion. The background thyroid parenchyma showed chronic lymphocytic thyroiditis. Mitotic rates were low, and no cases had any tumor necrosis. The pan-TRK and TTF1 testing was both positive in 3 cases, while S-100 and mammaglobin were both negative in them. FISH studies confirmed the NTRK3 gene rearrangement in all 3 cases. Studies on the TCGA datasets and literature revealed similar findings. Conclusions: NTRK3 gene rearrangement PTC is rare. It may be easily misdiagnosed due to the lack of histological and clinicopathological characteristics. Molecular studies such as pan-TRK immunostaining, FISH and even next-generation sequencing are needed to confirm the diagnosis. Immunohistochemistry of pan-TRK performed in the PTC cases without BRAF V600E mutation can be used as a good rapid-screening tool. With the emergence of pan-cancer tyrosine receptor kinase inhibitors, proper diagnosis of these tumors can help determine appropriate treatments and improve their outcomes.

Clinicopathological features and prognosis of high-grade B-cell lymphoma with MYC and bcl-2 and/or bcl-6 rearrangements / 中华病理学杂志

Objective: To investigate the clinicopathological characteristics and prognosis of high-grade B-cell lymphoma (HGBL) involving combined rearrangements of MYC, bcl-2 and bcl-6. Methods: A total of 1 138 cases of large B cell lymphoma (LBL) that were treated at the Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine from January 2017 to September 2020 were analyzed using fluorescence in situ hybridization (FISH) with probes against MYC, bcl-2 and bcl-6. The clinical and pathological data of the 45 patients with HGBL that had rearrangements of MYC and bcl-2 and/or bcl-6 were collected and retrospectively analyzed. Results: Among the 1 138 LBL, 45 (4.0%) cases had combined rearrangements of MYC, bcl-2 and/or bcl-6 that included 6 HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, 14 HGBL cases with MYC and bcl-2 rearrangements, and 25 HGBL cases with MYC and bcl-6 rearrangements. Of these 45 patients, 29 patients were male, and 16 patients were female, aged 29 to 83 years. HGBL with MYC, bcl-2 and bcl-6 rearrangements and HGBL with MYC and bcl-2 rearrangement were reclassified as the germinal center B-cell (GCB) subtype using the Hans algorithm. HGBL with MYC and bcl-6 rearrangement were reclassified as the GCB subtype (68.0%) and the non-GCB subtype (32.0%). The vast majority of HGBL cases had a high Ki-67 proliferation index. Most HGBL patients had advanced stage disease with a high IPI score and an increased LDH level. Also, some patients had clinical features including elevated plasma β2-microglobulin levels, B symptoms, and bone marrow involvement. The IPI scores and LDH levels were significantly different between the HGBL cases with MYC, bcl-2 and bcl-6 rearrangements and the HGBL cases with MYC and bcl-6 rearrangements (P<0.05). Compared with the HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, the HGBL cases with MYC and bcl-2 or bcl-6 rearrangements had a lower incidence of bone marrow involvement (P<0.05). There were no significant differences in the prognosis among HGBL cases with MYC, bcl-2 and bcl-6 rearrangements, the cases with MYC and bcl-2 rearrangements, and the cases with MYC and bcl-6 rearrangements (P>0.05). Conclusions: HGBL with MYC, bcl-2 and/or bcl-6 rearrangements are rare types of B-cell lymphoma with high degree of malignancy and have a short overall survival. To reduce misdiagnosis and improve diagnostic accuracy, it is necessary to assess the patients' clinical features and conduct histopathological, immunohistochemical and FISH analyses.

Correlation of NTRK genetic fusions with mismatch repair protein deletion in patients with colorectal cancer / 中华病理学杂志

Objective: To investigate the relationship between the expression of four mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) and NTRK genetic fusions in colorectal cancer. Methods: The paraffin-embedded tissue blocks of 830 cases of colorectal cancer were collected at the Affiliated Drum Tower Hospital, Nanjing University Medical School, China, from 2015 to 2019. Immunohistochemical and fluorescence in situ hybridization(FISH) method were used respectively to detect the expression of mismatch repair proteins and the break-apart of NTRKs; and the relationship between the expression of mismatch repair proteins and the NTRK genetic fusions was analyzed. Results: The overall mismatch repair protein deficiency (dMMR) rate was 9.88% (82/830), the mismatch repair proteins proficiency (pMMR) rate was 90.12%(748/830). The total deficiency rate of MLH1 protein was 9.04% (75/830), hPMS2 protein deficiency rate was 9.04% (75/830), MSH2 protein deficiency rate was 2.53% (21/830), MSH6 protein deficiency rate was 4.10% (34/830), the deficiency rate of synchronous MLH1 and PMS2 were 8.67% (72/830) and the deficiency rate of synchronous MSH2 and MSH6 were 2.17% (18/830). The dMMR group was associated with tumor location, different histological subgroups, tumor differentiation, AJCC stage and N stage (P<0.05). There were six cases (7.32%) carrying NTRK fusion by FISH among the 82 cases of dMMR, but only seven cases (0.94%) carrying NTRK fusion among the 748 cases of PMMR. The NTRKs translocation by FISH in all 13 cases were further confirmed by next generation sequencing. Among the clinicopathological characteristics, only differentiation showed significant difference between NTRK fusion positive and negative groups (P<0.05). More importantly, NTRK fusion was enriched in dMMR group (7.32% vs. 0.94%). Conclusion: In dMMR colorectal cancer group, the prevalence of NTRK fusion is higher than that in pMMR group.

Anaplastic lymphoma kinase-translocation renal cell carcinoma: clinical and pathological analysis / 中华病理学杂志

Objective: To investigate the clinicopathological features, molecular characteristics, differential diagnosis and prognosis of anaplastic lymphoma kinase (ALK)-translocation renal cell carcinoma. Methods: Two cases of ALK-translocation renal cell carcinoma diagnosed from January 2011 to December 2020 were retrospectively analyzed to characterize their morphological features, immunohistochemical expression and prognosis. Multiple molecular studies including fluorescence in situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR), and next-generation sequencing were performed to characterize the genetic alterations. Results: Two patients included one male and one female, with 59 and 57 years old, respectively. Morphologically, case 1 resembled collecting duct carcinoma or renal medullary carcinoma, which demonstrated tubular, microcapsule and reticular structures, with a remarkable myxoid background and lymphocytes infiltration; case 2 resembled Xp11.2 translocation renal cell carcinoma or type 2 papillary renal cell carcinoma, which demonstrated tubular papillary and focal solid structures, with flocculent cytoplasm and many foamy histiocytes, but without myxoid background and lymphocytes infiltration. Immunohistochemistry showed strongly positive expression of ALK. CK7, E-cadherin, vimentin, PAX8 and CD10 showed various degrees of expression, and other antibodies were nonreactive. A variety of molecular assays showed definite ALK gene translocation, with rare VCL-ALK gene fusion (VCL exon and 16-ALK exon 20) in case 1, and EML4-ALK gene fusion (EML4 exon and 2-ALK exon 20) in case 2. Conclusions: ALK-translocation renal cell carcinoma is rare with various morphological features, and is easy to miss and misdiagnose. The characteristic ALK expression and molecular detection of ALK translocation are helpful for diagnosing this type of renal cell carcinoma.

Papillary renal neoplasm with reverse polarity: a clinicopathological analysis / 中华病理学杂志

Objective: To study the clinical pathological characteristics, immunophenotype, molecular changes and prognosis of the papillary renal neoplasm with reverse polarity (PRNRP). Methods: Nine cases of PRNRP, diagnosed from 2013 to 2019, were retrieved from the Department of Pathology of Nanjing Jinling Hospital, Nanjing University School of Medicine. Histomorphology, immunophenotype and molecular genetics were analyzed with review of the literatures. Results: There were five male and four female patients, aged from 49 to 70 years, with an average age of 60.1 years. During a mean follow-up of 29 months, one patient died for other cause, and the others survived without disease. Microscopically, the tumor cells arranged in papillary structure with a fibrovascular core, the surface of which was covered with a single layer of cuboidal or columnar cells. The most prominent feature was that the tumor nuclei located at the top of the cytoplasm far from the basement membrane, and they were monotonous in size and arranged neatly with no or few nucleoli. Immunohistochemically, all nine cases of PRNRP showed diffuse positive expression of CK7 and E-cadherin, various degrees of P504s expression, and no expression of CD10 and CD117, with a Ki-67 index of 1%-3%. Unlike other papillary renal cell carcinoma, the nine cases of PRNRP all showed characteristic positive expression of GATA3. The fluorescence in situ hybridization assay showed that the majority of PRNRPs (8/9) did not have triploids on chromosomes 7 and 17. The sequencing of the KRAS gene confirmed the presence of a nonsense KRAS mutation in 8 of the 9 cases. Conclusions: PRNRP is a subtype of papillary renal cell carcinoma with characteristic morphological, immunophenotypic and molecular features, and indolent behaviors. More data are needed to define PRNRP as "carcinoma", and a definitive diagnosis of PRNRP is of great significance for proper treatment choice and accurate prognostication.

Paratesticular liposarcoma: the clinicopathological features of nineteen cases / 中华病理学杂志

Objective: To investigate the clinicopathological features and differential diagnoses of paratesticular liposarcoma. Methods: The cases were collected from 2012-2020, from the archives of the Department of Pathology, Peking University Third Hospital, with diagnosis confirmed by histology, immunostaining and FISH tests. Results: Totally 19 patients were enrolled (including 11 in-hospital patients and 8 consultant cases). The patients aged 37-84 years (mean 57 years). The preoperative clinical diagnoses were spermatic cord/inguinal masses (nine patients), scrotal masses (seven patients), and inguinal hernia (three patients). Six lesions recurred after local resection, including one case extending from pelvic liposarcoma. Histologically, there were 10 cases of well-differentiated liposarcoma (WDLPS) and nine cases of dedifferentiated liposarcoma (DDLPS). WDLPSs mostly showed the combined features of lipoma-like, inflammatory and sclerosing subtypes (six patients); the other four WDLPSs had pure lipoma-like subtype features. DDLPSs were low-grade (three patients) or high-grade (six patients), with the morphology resembling myxofibrosarcoma, inflammatory myofibroblastoma, spindle cell sarcoma, pleomorphic undifferentiated sarcoma and pleomorphic liposarcoma. Intense inflammatory cells infiltration was commonly observed in five WDLPSs and two DDLPSs. Ossification was observed in three tumors. Immunohistochemically, the tumors were positive for MDM2 (8/10) and CDK4 (10/10), which were expressed in lipo-differentiating cells, spindle cells in WDLPS, and in dediffferentiated components. S-100 was only expressed by lipocytes (10/10). CD34 expression was positive and diffuse in the stromal cells of WDLPSs and focal or diffuse in dedifferentiated areas (10/10). FISH tests with an MDM2 gene probe were positive (12/12). Conclusions: Paratesticular liposarcoma may be overlooked by both clinicians and pathologists. WDLPS and DDLPS predominate, showing various histologic divergences. The presence of amplification of the 12q14-q15 region (containing the MDM2 and CDK4 genes) is helpful for making the correct diagnosis.