OBJECTIVE: To investigate the relationship between Ig class switch recombination (CSR) and mismatch repair (MMR) protein, microsatellite phenotype in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). METHODS: Forty cases of MALT lymphoma archived in the Department of Pathology, Jiading District Central Hospital, Shanghai University of Medicine & Health Sciences were selected as the observation group, and twenty cases of benign lymphoid tissue hyperplasia were as the control group. The expressions of IgG, IgM, IgD, and IgA in both groups were detected by immunohistochemical double staining, and MMR proteins including MLH1, MSH2, MSH6, and PMS2 in both groups were detected by immunohistochemistry. Multiplex fluorescence PCR capillary electrophoresis was used to detect microsatellite phenotype in tumor and adjacent tissues of the experimental group. RESULTS: In the observation group, the proportions of single Ig heavy chain expression (modeⅠ), negative expression (modeⅡ), and multiple expression (mode Ⅲ) were 65% (26/40), 27.5% (11/40), and 7.5% (3/40), respectively, while in the control group were 0 (0/20), 5% (1/20), and 95% (19/20). The proportion of Ig heavy chain expression mode Ⅰ+Ⅱ in the observation group was 92.5%, which was significantly higher than 5% in the control group (P < 0.01). In the observation group, partial deletion of MMR protein was observed in 3 cases (7.5%), including 2 cases of MSH6 deletion and 1 case of both MSH6 and PMS2 deletion. In the control group, there was 1 case (5%) with PMS2 deletion. There was no significant difference in the deletion rate of MMR protein between the two groups ( P >0.05). A total of 5 cases of microsatellite instability (MSI) were detected in the observation group, including 1 case of low-frequency MSI (MSI-L), 4 cases of high-frequency MSI (MSI-H), and 2 cases of MSI-H with MSH6 deletion. When the loss expression of MSI-H or MMR protein was counted as a positive result, the MSI-H rate detected by PCR capillary electrophoresis was 10% (4/40), which was slightly higher than the MMR protein deletion rate detected by immunohistochemistry (7.5%, 3/40), but there was no statistically significant difference between the two groups (P >0.05). The MMR protein deletion rates among the Ig heavy chain protein expression mode Ⅰ, mode Ⅱ, and mode Ⅲ groups were 0 (0/26), 18.2% (2/11), and 33.3% (1/3), respectively. There was a statistically significant difference in the constituent ratios among the three groups (P < 0.05). The MMR protein deletion rates among the MSS, MSI-L, and MSI-H groups were 2.9% (1/35), 0 (0/1), and 50% (2/4), respectively. There was a statistically significant difference in the constituent ratios among the three groups (P < 0.05). MMR protein deficiency was positively correlated with Ig heavy chain expression pattern and MSI ( r =0.41, P < 0.05; r =0.48, P < 0.05), but Ig heavy chain expression pattern was not correlated with MSI ( r =0.02, P >0.05). CONCLUSION Ig heavy chain CSR detection is helpful for the differential diagnosis of MALT lymphoma. Low frequency MMR protein deletion and MSI-H phenotype exist in MALT lymphoma, which may be of certain value for the study of its occurrence, development and clinical treatment.
Humans ; Lymphoma, B-Cell, Marginal Zone/genetics* ; DNA Mismatch Repair ; Immunoglobulin Class Switching ; DNA-Binding Proteins/metabolism* ; MutS Homolog 2 Protein ; Microsatellite Repeats ; Phenotype ; MutL Protein Homolog 1 ; Mismatch Repair Endonuclease PMS2 ; Male

BACKGROUND: Primary pulmonary mucoepidermoid carcinoma (PMEC) is an exceedingly rare malignancy originating from bronchial submucosal glands, accounting for <0.2% of lung cancers. Histologically characterized by a triphasic composition of mucinous, epidermoid, and intermediate cells, PMEC is classified into low-grade (favorable prognosis) and high-grade (aggressive behavior) subtypes. This study aimed to investigate the clinicopathological characteristics and prognostic indicators of PMEC. METHODS: Clinicopathological, radiological, molecular, and survival data from 26 PMEC patients were retrospectively analyzed, including immunohistochemical profiles and MAML2 rearrangement status, supplemented by literature review. RESULTS: The cohort comprised 14 males and 12 females (mean age: 55.6 years). Eight patients (30.8%) were smokers, and 19 (73.1%) presented with symptoms. Central tumors predominated (n=19, 73.1%) versus peripheral lesions (n=7, 26.9%). Computed tomography (CT) imaging consistently revealed hypo-to-isodense masses/nodules. Pathologically, 19 cases were low-grade and 7 high-grade. Immunohistochemically, the tumor cells were positive for CK7, P40, P63 and CK5/6, and the Ki-67 index ranged from 2% to 70%. MAML2 rearrangement was detected in 52.4% (11/21) of tested cases. Clinical staging distribution: stage I (n=14), stage II (n=8), stage III (n=3), stage IV (n=1). Treatment modalities: radical surgery alone (n=13), surgery with adjuvant chemotherapy (n=11), chemoradiotherapy (n=1), and conservative management (n=1). With a median follow-up of 57 months, 6 patients (23.1%) died. Prognostic analysis demonstrated: (1) Significantly inferior survival in high-grade versus low-grade groups (P<0.05); (2) Lymph node metastasis, advanced stage, Ki-67>20%, and high-grade histology significantly correlated with reduced overall survival (P<0.05); (3) Lymph node metastasis constituted an independent poor prognostic factor (HR=12.73, 95%CI: 1.22-132.96). CONCLUSIONS PMEC exhibits distinct clinicopathological features, with MAML2 rearrangement present in approximately half of cases. Lymph node metastasis, advanced stage, high Ki-67 proliferation index, and high-grade histology are key determinants of poor prognosis, with lymph node metastasis serving as an independent risk factor.
Humans ; Male ; Female ; Middle Aged ; Carcinoma, Mucoepidermoid/mortality* ; Lung Neoplasms/mortality* ; Trans-Activators/genetics* ; Prognosis ; Adult ; Gene Rearrangement ; Aged ; Retrospective Studies ; Transcription Factors/genetics* ; DNA-Binding Proteins/genetics*

OBJECTIVE: To present on a prenatally diagnosed case with complex structural rearrangements of chromosome 8. METHODS: Chromosome karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) were carried out for a fetus with increased nuchal thickness. RESULTS: The karyotype of the amniotic fluid sample showed extra materials on 8p. FISH revealed a centromeric signal at the terminal of 8p with absence of telomeric signal. CMA revealed partial deletion of 8p23.3 [(208049_2256732)×1], partial duplication of 8p23.3p23.2 [(2259519_3016818)×3], and partial duplication of 8q [8q11.1q12.2(45951900_60989083)×3]. CONCLUSION The complex structural rearrangements of chromosome 8 in this case has differed from the commonly seen inv dup del(8p).
Female ; Pregnancy ; Humans ; Chromosomes, Human, Pair 8/genetics* ; In Situ Hybridization, Fluorescence ; Gene Rearrangement ; Prenatal Diagnosis ; Centromere

OBJECTIVE: To investigate the clinical and prognostic characteristics of primary acute myeloid leukemia (AML) with 11q23/KMT2A rearrangements. METHODS: Clinical data of 90 patients with primary AML and 11q23/KMT2A rearrangements were analyzed retrospectively. RESULTS: By karyotyping analysis, 80 of the 90 patients had translocations involving 11q23/KMT2A, with t(9;11)(p22;q23), t(6;11)(q27;q23), t(10;11)(p12;q23) and t(11;19)(q23;p13) being the most common ones, while 10 cases were found to have non-translocation abnormalities. The overall complete remission (CR) rate was 75.6%, and patients with t(6;11) had lower CR rate compared with non-t(6;11) patients (47.1% vs. 82.2%, P = 0.005). After a median follow-up of 24.5 months, the patients receiving allo-hematopoietic stem cell transplantation (allo-HSCT) had significantly higher 3-year overall survival (OS) (80.3% vs. 16.6%, P < 0.001) and 3-year event-free survival (EFS) (73.5% vs. 16.3%, P < 0.001) compared with non-transplant patients. Patients with t(6;11) had the lowest 3-year OS (11.8% vs. 56.0%, P < 0.001) and 3-year EFS (5.9% vs. 53.8%, P < 0.001) compared with other type of abnormalities. No significant difference was noted in the survival between patients with t(9;11) and non-t(9;11) regardless whether they had received HSCT. CONCLUSION The clinical characteristics of primary AML with 11q23/KMT2A rearrangements are heterogeneous. Patients did not receive HSCT had poorer survival, particularly with the presence of t(6;11). Allo-HSCT could significantly improve the survival of such patients.
Humans ; Retrospective Studies ; Leukemia, Myeloid, Acute/therapy* ; Translocation, Genetic ; Gene Rearrangement ; Prognosis

Humans ; Leukemia, Myeloid, Acute/genetics* ; Nuclear Pore Complex Proteins/genetics* ; Gene Rearrangement ; Translocation, Genetic ; Oncogene Proteins, Fusion/genetics*

Humans ; China ; Chromosome Aberrations ; Consensus ; Gene Rearrangement ; Lymphoma/genetics*

Objective:b> To investigate the clinicopathological features, immunophenotypes and molecular genetics of fibroma of tendon sheath (FTS). Methods:b> One hundred and thirty-four cases of FTS or tenosynovial fibroma diagnosed in the Department of Pathology, West China Hospital, Sichuan University, Chengdu, China from January 2008 to April 2019 were selected. The clinical and histologic features of these cases were retrospectively reviewed. Immunohistochemistry, fluorescence in situ hybridization (FISH) and reverse transcription-polymerase chain reaction (RT-PCR) were performed on the above cases. Results:b> There were a total of 134 cases of FTS, including 67 males and 67 females. The patients' median age was 38 years (ranged from 2 to 85 years). The median tumor size was 1.8 cm (ranged from 0.1 to 6.8 cm). The most common site was the upper extremity (76/134, 57%). Follow-up data was available in 28 cases and there was no detectable recurrence. Classic FTS (114 cases) were well-defined and hypocellular. A few spindle-shaped fibroblasts were scattered in the dense collagenous sclerotic stroma. Characteristically elongated slit-like spaces or thin-walled vessels were observed. Most of cellular FTSs (20 cases) were well-defined and the area with increased cellularity of the spindle cells coexisted with classic FTS. There were occasional mitotic figures, but no atypical mitotic figures. Immunohistochemistry was performed in 8 cases of classic FTS and most cases were positive for SMA (5/8). Immunohistochemistry was also performed in 13 cases of cellular FTS and showed 100% positive rate for SMA. FISH was conducted on 20 cases of cellular FTS and 32 cases of classical FTS. USP6 gene rearrangement was found in 11/20 of cellular FTS. Among 12 cases of CFTS with nodular fasciitis (NF)-like morphological feature, 7 cases showed USP6 gene rearrangement. The rearrangement proportion of USP6 gene in cellular FTS without NF-like morphological features was 4/8. By contrast, 3% (1/32) of the classic FTS showed USP6 gene rearrangement. RT-PCR was performed in those cases with detected USP6 gene rearrangement and sufficient tissue samples for RT-PCR. The MYH9-USP6 fusion gene was detected in 1 case (1/8) of the cellular FTSs, while no target fusion partner was detected in the classic FTS. Conclusions:b> FTS is a relatively rare benign fibroblastic or myofibroblastic tumor. Our study and recent literature find that some of the classic FTS also show USP6 gene rearrangements, suggesting that classical FTS and cellular FTS are likely to be at different stages of the same disease (spectrum). FISH for USP6 gene rearrangement may be used as an important auxiliary diagnostic tool in distinguishing FTS from other tumors.
Male ; Female ; Humans ; Gene Rearrangement ; In Situ Hybridization, Fluorescence ; Retrospective Studies ; Fibroma/pathology* ; Fasciitis/genetics* ; Ubiquitin Thiolesterase ; Tendons/pathology*

Humans ; Fasciitis/pathology* ; Fibroma/pathology* ; Gene Rearrangement ; Proto-Oncogene Proteins/genetics* ; Ubiquitin Thiolesterase

Humans ; Protein-Tyrosine Kinases/genetics* ; Proto-Oncogene Proteins/genetics* ; Lung Neoplasms/pathology* ; Mutation ; ErbB Receptors/genetics* ; Oncogene Proteins, Fusion/genetics* ; Gene Rearrangement

Humans ; Receptor, trkA/genetics* ; Neoplasms/genetics* ; Biomarkers, Tumor ; Gene Rearrangement ; Oncogene Proteins, Fusion/genetics*