AntDAS-GCMS: A New Comprehensive Data Analysis Platform for GC-MS-Based Untargeted Metabolomics with the Advantage of Addressing the Time Shift Problem.

Over the years, a number of state-of-the-art data analysis tools have been developed to provide a comprehensive analysis of data collected from gas chromatography-mass spectrometry (GC-MS). Unfortunately, the time shift problem remains unsolved in these tools. Here, we developed a novel comprehensive data analysis strategy for GC-MS-based untargeted metabolomics (AntDAS-GCMS) to perform total ion chromatogram peak detection, peak resolution, time shift correction, component registration, statistical analysis, and compound identification. Time shift correction was specifically optimized in this work. The information on mass spectra and elution profiles of compounds was used to search for inherent landmarks within analyzed samples to resolve the time shift problem across samples efficiently and accurately. The performance of our AntDAS-GCMS was comprehensively investigated by using four complex GC-MS data sets with various types of time shift problems. Meanwhile, AntDAS-GCMS was compared with advanced GC-MS data analysis tools and classic time shift correction methods. Results indicated that AntDAS-GCMS could achieve the best performance compared to the other methods.

Design, synthesis, and evaluation of novel ferrostatin derivatives for the prevention of HG-induced VEC ferroptosis.

Ferroptosis is a nonapoptotic, iron-catalyzed form of regulated cell death. It has been shown that high glucose (HG) could induce ferroptosis in vascular endothelial cells (VECs), consequently contributing to the development of various diseases. This study synthesized and evaluated a series of novel ferrostatin-1 (Fer-1) derivatives fused with a benzohydrazide moiety to prevent HG-induced VEC ferroptosis. Several promising compounds showed similar or improved inhibitory effects compared to positive control Fer-1. The most effective candidate 12 exhibited better protection against erastin-induced ferroptosis and high glucose-induced ferroptosis in VECs. Mechanistic studies revealed that compound 12 prevented mitochondrial damage, reduced intracellular ROS accumulation, upregulated the expression of GPX4, and decreased the amounts of ferrous ion, LPO and MDA in VECs. However, compound 12 still exhibited undesirable microsomal stability like Fer-1, suggesting the need for further optimization. Overall, the present findings highlight ferroptosis inhibitor 12 as a potential lead compound for treating ferroptosis-associated vascular diseases.

Genome-wide analysis and expression profiling of the HD-ZIP gene family in kiwifruit.

The homeodomain-leucine zipper (HD-Zip) gene family plays a pivotal role in plant development and stress responses. Nevertheless, a comprehensive characterization of the HD-Zip gene family in kiwifruit has been lacking. In this study, we have systematically identified 70 HD-Zip genes in the Actinidia chinensis (Ac) genome and 55 in the Actinidia eriantha (Ae) genome. These genes have been categorized into four subfamilies (HD-Zip I, II, III, and IV) through rigorous phylogenetic analysis. Analysis of synteny patterns and selection pressures has provided insights into how whole-genome duplication (WGD) or segmental may have contributed to the divergence in gene numbers between these two kiwifruit species, with duplicated gene pairs undergoing purifying selection. Furthermore, our study has unveiled tissue-specific expression patterns among kiwifruit HD-Zip genes, with some genes identified as key regulators of kiwifruit responses to bacterial canker disease and postharvest processes. These findings not only offer valuable insights into the evolutionary and functional characteristics of kiwifruit HD-Zips but also shed light on their potential roles in plant growth and development.

Red blood cell distribution width is associated with sarcopenia risk in early-stage non-small cell lung cancer.

BACKGROUND: Sarcopenia has received increasing attention in non-small cell lung cancer (NSCLC). Red blood cell distribution width (RDW) is a significant component of the complete blood count and indicates the heterogeneity of erythrocyte volume. Little information is known about RDW in relation to sarcopenia in early-stage (IA-IIIA) NSCLC. The purpose of the present study was to investigate the association between RDW and sarcopenia risk in early-stage NSCLC patients. METHODS: This study included 378 patients with pathologically confirmed stage IA-IIIA NSCLC. Sarcopenia was defined by measuring the skeletal muscle index (SMI) at the eleventh thoracic vertebra level. The maximum Youden index on the receiver operating characteristic (ROC) curve was used to estimate the cutoff value for RDW to predict sarcopenia. Logistic regression analyses were carried out to assess the independent risk factors for sarcopenia in NSCLC. RESULTS: The ROC curve indicated that the best cutoff point for RDW to predict sarcopenia was 12.9 (sensitivity of 43.80% and specificity of 76.76%, respectively). Moreover, there were significant differences in hemoglobin (p < 0.001), comorbidities (p = 0.001), histological type (p = 0.002), and cancer stage (p = 0.032) between the high RDW and low RDW groups. Logistic regression analyses revealed that high RDW is an independent risk factor for sarcopenia in early-stage NSCLC. CONCLUSION: RDW is associated with sarcopenia risk in early-stage NSCLC.

Preoperative small airway dysfunction is associated with skeletal muscle loss in early-stage non-small cell lung cancer.

BACKGROUND: Postoperative skeletal muscle loss (SM loss) was reported to be associated with a poor prognosis in early-stage non-small cell lung cancer (NSCLC). Small airway dysfunction (SAD) is a common but neglected respiratory abnormality. Little information is known about the association between preoperative SAD and postoperative SM loss in early-stage NSCLC. Therefore, this study aimed to investigate the correlation between preoperative SAD and SM loss after surgery in early-stage NSCLC patients. METHODS: There were 348 NSCLC patients with stages I-IIIA in this study from January 2017 to December 2020. All CT images were contrast-enhanced scans, and the skeletal muscle index (SMI) was measured using CT images. A 10.0% decrease in SMI over 12 months was determined as the cut-off value to define excessive SM loss. Logistic regression analyses were used to examine the relationship between SAD and SM loss. RESULTS: This study included 348 subjects who underwent pulmonary operation (159 males and 189 females; mean age: 57.5 ± 8.8 years). 152 (43.7%) patients were identified as having SAD before surgery, and 179 patients (51.4%) were identified as having SM loss after 1 year. Moreover, a higher incidence of SAD was found in the SM loss group compared with that in the non-SM loss group (52.0% vs. 34.9%, p = 0.001). The patients with SAD were older, had larger tumor size, and had lower albumin levels. Furthermore, there were significant correlations between the lung function parameters manifesting SAD and the percentage change in SMI (for the forced expiratory flow when 75% of forced vital capacity has been exhaled (FEF75%), Pearson r=-0.107, p = 0.046; for FEF50%, r = -0.142, p = 0.008; and for FEF25-75%, r=-0.124, p = 0.021; respectively). However, no significant correlations were found between SMI and the lung function parameters reflecting proximal airway obstruction (p > 0.05). Logistic regression analysis revealed that preoperative SAD (HR, 2.465; 95% CI, 1.256-4.838; p = 0.009) was independent risk factor for postoperative SM loss in early-stage NSCLC. In addition, multivariable analysis revealed that SAD (HR, 1.816; 95% CI, 1.025-3.216, P = 0.041) were associated with postoperative complications. CONCLUSION: Preoperative SAD is significantly associated with postoperative complications and SM loss in early NSCLC patients. Our results suggest that preoperative assessment of SAD may be useful for risk stratification of surgical candidates with potential for targeted interventions.

Lower subcutaneous fat index predicts bone metastasis in breast cancer.

BACKGROUND: Bone metastases affect 50% to 70% of breast cancer (BC) patients and have a high mortality rate. Adipose tissue loss plays a pivotal role in the progression of cancer. OBJECTIVE: This study aims to evaluate the prognostic value of adipose tissue for bone metastasis in BC patients. METHODS: 517 BC patients were studied retrospectively. Patients' characteristics before the surgery were collected. Quantitative measurements of the subcutaneous fat index (SFI) were performed at the level of the eleventh thoracic vertebra. In order to adjust for the heterogeneity between the low SFI and high SFI groups, propensity score matching (PSM) was used. The Kaplan-Meier method was used to estimate the 5-year bone metastatic incidence. The prognostic analysis was performed with the Cox regression models. RESULTS: Compared with the patients without bone metastasis, the patients with bone metastasis had reduced SFI levels. In addition, Kaplan-Meier analysis revealed that patients with low SFI were more likely to develop bone metastases. The independent predictive value of SFI for bone metastases was confirmed by Cox regression analysis. The survival analysis was repeated after PSM with a 1:1 ratio, yielding similar results (P< 0.05). CONCLUSIONS: SFI is an independent predictor of bone metastasis in BC patients.

Dual Synthetic Receptor-Based Sandwich Electrochemical Sensor for Highly Selective and Ultrasensitive Detection of Pathogenic Bacteria at the Single-Cell Level.

Sensitive and rapid detection of pathogenic bacteria is essential for effective source control and prevention of microbial infectious diseases. However, it remains a substantial challenge to rapidly detect bacteria at the single-cell level. Herein, we present an electrochemical sandwich sensor for highly selective and ultrasensitive detection of a single bacterial cell based on dual recognition by the bacteria-imprinted polymer film (BIF) and aptamer. The BIF was used as the capture probe, which was in situ fabricated on the electrode surface within 15 min via electropolymerization. The aptamer and electroactive 6-(Ferrocenyl)hexanethiol cofunctionalized gold nanoparticles (Au@Fc-Apt) were employed as the signal probe. Once the target bacteria were anchored on the BIF-modified electrode, the Au@Fc-Apt was further specifically bound to the bacteria, generating enhanced current signals for ultrasensitive detection of Staphylococcus aureus down to a single cell in phosphate buffer solution. Even in the complex milk samples, the sensor could detect as low as 10 CFU mL-1 of S. aureus without any complicated pretreatment except for 10-fold dilution. Moreover, the current response to the target bacteria was hardly affected by the coexisting multiple interfering bacteria, whose number is 30 times higher than the target, demonstrating the excellent selectivity of the sensor. Compared with most reported sandwich-type electrochemical sensors, this assay is more sensitive and more rapid, requiring less time (1.5 h) for the sensing interface construction. By virtue of its sensitivity, rapidity, selectivity, and cost-effectiveness, the sensor can serve as a universal detection platform for monitoring pathogenic bacteria in fields of food/public safety.

PcEiger links the Imd/Relish pathway to ROS production in the intestine of the red swamp crayfish.

In the arthropod gut, commensal microbiota maintain the immune deficiency (Imd)/Relish pathway for expression of antimicrobial peptides, whereas pathogenic bacteria induce dual oxidase 2 (Duox2) for production of extracellular microbicidal reactive oxygen species (ROS). The Imd/Relish pathway and the Duox2/ROS system are regarded as independent systems. Here, we report that these two systems are bridged by the tumor necrosis factor (TNF) ortholog PcEiger in the red swamp crayfish Procambarus clarkii. PcEiger expression is induced by commensal bacteria or the Imd/Relish pathway. PcEiger knockdown alters bacterial abundance and community composition due to variations in the oxidative status of the intestine. PcEiger induces Duox2 expression and ROS production by regulating the activity of the transcription factor Atf2. Moreover, PcEiger mediates regulation of the Duox2/ROS system by commensal bacteria and the Imd/Relish pathway. Our findings suggest that the Imd/Relish pathway regulates the Duox2/ROS system via PcEiger in P. clarkii, and they provide insights into the crosstalk between these two important mechanisms for arthropod intestinal immunity.

Systemic lupus erythematosus with multicentric reticulohistiocytosis: A case report.

BACKGROUND: Multicentric reticulohistiocytosis (MRH)/systemic lupus erythematosus (SLE) overlap syndrome is an uncommon disease in the clinic and is diagnosed through characteristic clinical manifestations, histopathology, and immunopathology. Here, we report the case of a 30-year-old woman with SLE who developed MRH. CASE SUMMARY: A 30-year-old woman with a history of polyarthritis for the past 12 years had multiple skin nodules on her body for 10 years, including the sacrococcygeal area, dorsum of the hands, interphalangeal joint of the feet and sternoclavicular joint. The histopathology of a biopsy of the distal interphalangeal joint of the hands revealed granulomatous inflammation, fibrous hyperplasia with ground-glass degeneration, inflammatory cell exudation and focal necrosis. The immunohistochemical stains showed positive staining for CD68 and negative staining for S100 and acid-fast staining. The patient was diagnosed with SLE with MRH. Her symptoms were improved after a combined treatment of prednisone, hydroxychloroquine and cyclophosphamide. CONCLUSION: MRH/SLE overlap syndrome is difficult to diagnose and treat. Cyclophosphamide may be an alternative choice for the treatment of MRH.

AntDAS-DDA: A New Platform for Data-Dependent Acquisition Mode-Based Untargeted Metabolomic Profiling Analysis with Advantage of Recognizing Insource Fragment Ions to Improve Compound Identification.

Data-dependent acquisition (DDA) mode in ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) can provide massive amounts of MS1 and MS/MS information of compounds in untargeted metabolomics and can thus facilitate compound identification greatly. In this work, we developed a new platform called AntDAS-DDA for the automatic processing of UHPLC-HRMS data sets acquired under the DDA mode. Several algorithms, including extracted ion chromatogram extraction, feature extraction, MS/MS spectrum construction, fragment ion identification, and MS1 spectrum construction, were developed within the platform. The performance of AntDAS-DDA was investigated comprehensively with a mixture of standard and complex plant data sets. Results suggested that features in complex sample matrices can be extracted effectively, and the constructed MS1 and MS/MS spectra can benefit in compound identification greatly. The efficiency of compound identification can be improved by about 20%. AntDAS-DDA can take full advantage of MS/MS information in multiple sample analyses and provide more MS/MS spectra than single sample analysis. A comparison with advanced data analysis tools indicated that AntDAS-DDA may be used as an alternative for routine UHPLC-HRMS-based untargeted metabolomics. AntDAS-DDA is freely available at http://www.pmdb.org.cn/antdasdda.

Complement-related proteins in crustacean immunity.

As an important part of innate immune system, complement system is widely involved in defense response and immune regulation, and plays an important biological role. The complement system has been deeply studied. More than 30 complement-related molecules and three major complement-activation pathways have been identified in vertebrates. Crustacean animals do not have complement system. There are only some complement-related proteins in crustaceans which are important for host defense. In this review, we summarize the current knowledge about complement-related proteins in crustaceans, and their functions in crustacean immunity. We also make a comparation of the crustacean pro-phenoloxidase activating system and the mammalian complement system. This review provides a better understanding of the evolution and function of complement-related proteins in crustaceans.

Small immune effectors coordinate peptidoglycan-derived immunity to regulate intestinal bacteria in shrimp.

Small antibacterial effectors, including lysozymes, lectins, and antimicrobial peptides, are key regulators of intestinal immunity. However, whether there is coordination among them during regulation is an interesting, but largely unknown, issue. In the present study, we revealed that small effectors synergistically regulate peptidoglycan-derived intestinal immunity in the kuruma shrimp, Marsupenaeus japonicus. A C-type lysozyme (LysC) was screened as a responsive factor for the intestine-bacteria interaction. LysC functions to restrict intestinal bacteria, mainly by cleaving Photobacterium damselae peptidoglycan to generate muropeptides which are powerful stimulators that induce anti-lipopolysaccharides factor B1 (AlfB1), an effective bactericidal peptide. The muropeptides also induce a C-type lectin (Ctl24), which recognizes peptidoglycan and coats bacteria. By counteracting LysC-mediated muropeptide release and AlfB1's bactericidal activity, Ctl24 prevents the continuous elimination of intestinal bacteria. Therefore, this study demonstrates a mechanism by which small immune effectors coordinate to achieve intestinal homeostasis, and provides new insights into peptidoglycan-derived intestinal immunity in invertebrates.

[Clinical Analysis of Elderly Patients with AML/High-Risk MDS].

OBJECTIVE: To analyze the clinical features of acute myeloid leukemia (AML)/high-risk myelodysplastic syndrome (MDS) patients aged over 60 years old. METHODS: The clinical data of 61 elderly newly diagnosed patients with AML and high-risk MDS who submitted to the Department of Hematology/Oncology of the First Affiliated Hospital of Tsinghua University from January 2009 to April 16, 2021 were retrospectively analyzed. These patients were divided into chemotherapy group (45 cases) and supportive treatment group (16 cases). The overall survival (OS) was analyzed by Kaplan-Meier method, and the prognostic factors of survival were analyzed by multivariate Cox regression. RESULTS: After 2 cycles of induction chemotherapy, the complete remission (CR) rate was 37.8% (17/45), and overall response rate was 62.2% (28/45) in the chemotherapy group. The median OS in the chemotherapy group and supportive treatment group was 11.3 (0.07-43) and 1.6 (0.33-7.72) months, respectively (P<0.001). The median OS in patients who reached CR or did not reach after 1 cycle of induction chemotherapy was 19.8 (10-30.63) and 8.17 (0.07-43) months, respectively (P<0.05), while after 2 cycles was 22.7 (4.2-43) and 7.26 (0.07-26) months, respectively (P<0.001). Univariate analysis showed that age > 80 years old, CCI score > 2, PS score > 2 and supportive treatment were the adverse prognostic factors for OS. Further multivariate analysis suggested that chemotherapy was the only independent prognostic factor for OS (HR=0.140, 95%CI: 0.048-0.409, P<0.001). In the chemotherapy group, univariate analysis showed that CCI score > 2 and failure to reach CR after induction chemotherapy were poor prognostic factors. Multivariate analysis showed that CCI score > 2 (HR=0.139, 95%CI: 0.050-0.384, P<0.001) and failure to achieve CR after induction chemotherapy (HR=0.103, 95%CI: 0.041-0.259, P<0.001) were the adverse prognostic factors for OS. The patients were tolerant to side-effect of chemotherapy. CONCLUSION: Appropriate chemotherapy can prolong the survival of elderly patients with AML and high-risk MDS.

Inhibitory effects of luteolin on TLR3-mediated inflammation caused by TAK/NF-κB signaling in human corneal fibroblasts.

AIM: To study the role of luteolin (LUT) in the expression of toll-like receptors 3 (TLR3) ligand polyI:C stimulated inflammatory factors in human corneal fibroblasts (HCFs). METHODS: HCFs cells were cultivated with or without LUT or polyI:C. The expression levels of interleukin (IL)-6, IL-8, monocyte chemotactic protein-1 (MCP-1), vascular cell adhesion molecule (VCAM)-1, as well as intercellular adhesion molecule (ICAM)-1 were measured using enzyme-linked immunosorbent assay (ELISA), immunoblotting or reverse transcription-quantitative polymerase chain reaction (PCR) analyses. Immunoblotting was used to assess toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-ß (TRIF), TLR3, transforming growth factor-b-activated kinase 1 (TAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), the transcription factor AP-1, as well as transcription factor nuclear factor (NF-κB)-inhibitory protein IκB-α degradation and phosphorylation. Immunofluorescence assays were used to localize the cellular location of the p65 subunit of NF-κB. RESULTS: Corneal fibroblasts exposed to polyI:C demonstrated decreased VCAM-1, ICAM-1, MCP-1, IL-6, and IL-8 expression levels upon exposure to LUT in a time-dependent and concentration-dependent manner. LUT was observed to suppress polyI:C-triggered expression of TLR3, the translocation of NF-κB p65 into cell nuclei, as well as the phosphorylation of TAK, c-Jun, and IκB-α, while no impact on the expression levels of TRIF and TRAF6 were observed. CONCLUSION: LUT suppress the expression of proinflammatory adhesion molecules, chemokines, and cytokines in polyI:C exposed HCFs. These effects are likely mediated through TAK/NF-κB signal attenuation. Therefore, LUT is a candidate molecule that can prevent the TLR3-mediated inflammation response associated with corneal viral infection.

A new platform for untargeted UHPLC-HRMS data analysis to address the time-shift problem.

Substantial deviations in retention times among samples pose a great challenge for the accurate screening and identifying of metabolites by ultrahigh-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). In this study, a coarse-to-refined time-shift correction methodology was proposed to efficiently address this problem. Metabolites producing multiple fragment ions were automatically selected as landmarks to generate pseudo-mass spectra for a coarse time-shift correction. Refined peak alignment for extracted ion chromatograms was then performed by using a moving window-based multiple-peak alignment strategy. Based on this novel coarse-to-refined time-shift correction methodology, a new comprehensive UHPLC-HRMS data analysis platform was developed for UHPLC-HRMS-based metabolomics. Original datasets were employed as inputs to automatically extract and register features in the dataset and to distinguish fragment ions from metabolites for chemometric analysis. Its performance was further evaluated using complex datasets, and the results suggest that the new platform can satisfactorily resolve the time-shift problem and is comparable with commonly used UHPLC-HRMS data analysis tools such as XCMS Online, MS-DIAL, Mzmine2, and Progenesis QI. The new platform can be downloaded from: http://www.pmdb.org.cn/antdas2tsc.

Proteomic and metabolomic analysis of Nicotiana benthamiana under dark stress.

Exposure to extended periods of darkness is a common source of abiotic stress that significantly affects plant growth and development. To understand how Nicotiana benthamiana responds to dark stress, the proteomes and metabolomes of leaves treated with darkness were studied. In total, 5763 proteins and 165 primary metabolites were identified following dark treatment. Additionally, the expression of autophagy-related gene (ATG) proteins was transiently upregulated. Weighted gene coexpression network analysis (WGCNA) was utilized to find the protein modules associated with the response to dark stress. A total of four coexpression modules were obtained. The results indicated that heat-shock protein (HSP70), SnRK1-interacting protein 1, 2A phosphatase-associated protein of 46 kDa (Tap46), and glutamate dehydrogenase (GDH) might play crucial roles in N. benthamiana's response to dark stress. Furthermore, a protein-protein interaction (PPI) network was constructed and top-degreed proteins were predicted to identify potential key factors in the response to dark stress. These proteins include isopropylmalate isomerase (IPMI), eukaryotic elongation factor 5A (ELF5A), and ribosomal protein 5A (RPS5A). Finally, metabolic analysis suggested that some amino acids and sugars were involved in the dark-responsive pathways. Thus, these results provide a new avenue for understanding the defensive mechanism against dark stress at the protein and metabolic levels in N. benthamiana.

Dynamic changes in the radiologic manifestation of a recurrent checkpoint inhibitor related pneumonitis in a non-small cell lung cancer patient: A case report.

BACKGROUND: As immune checkpoint inhibitors (ICIs) have become widely used in lung cancer treatment, immune-related adverse events (irAEs) warrant sufficient attention. Checkpoint inhibitor-related pneumonitis (CIP) is one of the most concerning adverse events as it is uncommon but life threatening. CASE SUMMARY: The patient whose case is reported here experienced three episodes of CIP in a span of 4 mon. Interestingly, the three episodes of CIP involved different regions of the lung separately. Taking these pneumonitis areas together makes nearly a whole lung area. CONCLUSION: This case showed that recurrent CIPs may occur repeatedly until the whole lung is involved, suggesting that the follow-up period of CIP should be long enough, and the rechallenge of ICI should be done with due caution.

Growth and thermal maturation of the Toba magma reservoir.

The Toba volcanic system in Indonesia has produced two of the largest eruptions (>2,000 km3 dense-rock equivalent [DRE] each) on Earth since the Quaternary. U-Pb crystallization ages of zircon span a period of ∼600 ky before each eruptive event, and in the run-up to each eruption, the mean and variance of the zircons' U content decrease. To quantify the process of accumulation of eruptible magma underneath the Toba caldera, we integrated these observations with thermal and geochemical modeling. We show that caldera-forming eruptions at Toba are the result of progressive thermal maturation of the upper crustal magma reservoir, which grows and chemically homogenizes, by sustained magma influx at average volumetric rates between 0.008 and 0.01 km3/y over the past 2.2 My. Protracted thermal pulses related to magma-recharge events prime the system for eruption without necessarily requiring an increased magma-recharge rate before the two supereruptions. If the rate of magma input was maintained since the last supereruption of Toba at 75 ka, eruptible magma is currently accumulating at a minimum rate of ∼4.2 km3 per millennium, and the current estimate of the total volume of potentially eruptible magma available today is a minimum of ∼315 km3 Our approach to evaluate magma flux and the rate of eruptible magma accumulation is applicable to other volcanic systems capable of producing supereruptions and thereby could help in assessing the potential of active volcanic systems to feed supereruptions.

Comparative clinicopathological and immunohistochemical study of micronodular thymoma and micronodular thymic carcinoma with lymphoid stroma.

AIM: To elucidate the clinicopathological and immunohistochemical characteristics of micronodular thymomas (MNTs) and micronodular thymic carcinomas (MNCs) with lymphoid stroma. METHODS: We examined four cases of MNTs and three cases of MNCs pathologically and immunohistochemically. RESULTS: There were prominent cystic changes infive of the seven cases. The neoplasms contained epithelial tumour cells arranged in a micronodular growth pattern lined by cystic walls and separated by abundant lymphoid stroma. Only the tumour cell component of MNCs showed signs of malignancy characterised by cytological atypia and increased mitotic activity. Neoplastic MNC epithelial cells showed strong positivity for CD5 and CD117. However, no immature lymphocytes (TdT-positive and CD99-positive) were present in and around the tumour nodules. None of the patients died or suffered from disease due to MNTs or MNCs. CONCLUSION: MNTs and MNCs are rare and less aggressive forms of thymic tumours and can be differentially diagnosed by immunohistochemistry.