Objective: To investigate the clinicopathological and molecular characteristics of neurocutaneous melanosis in children caused by NRAS gene variants. Methods: Three cases of neurocutaneous melanosis from Children's Hospital of Fudan University (case 1 and case 2) and Shanghai Children's Hospital, School of Medicine Shanghai Jiaotong University (case 3) from July 2022 to February 2023 were collected. The clinical, histopathological, immunohistochemical and genetic results of three patients were retrospectively analyzed. The literatures were reviewed. Results: The patients were all female, aged 5, 4 and 3 years, respectively. The patients presented with severe headache with other symptoms of increased intracranial pressure. Physical examination showed multiple congenital melanocytic nevi throughout the body. Imaging examination showed intracranial masses, which were located in the right cerebellum, pineal gland and left temporal lobe, respectively. The maximum diameters were 39.1 mm, 72.8 mm and 52.2 mm, respectively. Histologically, the tumor showed diffuse sheets of round or oval-shaped cells arranged in nests, with marked nuclear atypia, eosinophilic cytoplasm, dark nuclei, and prominent nucleoli. Giant tumor cells were seen and mitotic figures were easily observed. There were hemorrhage and necrosis. Pigment granules were found in the cytoplasm and stroma in case 1 and case 2. Immunohistochemically, the tumor cells showed diffuse and strong staining of SOX10, S-100, HMB45 and Melan A, but did not express GFAP and CKpan. The Ki-67 proliferation index ranged from 30% to 80%. Genetic testing showed that case 1 and case 2 had NRAS Q61K matation, and case 3 had NRAS Q61R mutation. Case 1 and case 3 underwent complete resection of the tumor combined with chemotherapy. Case 2 was diagnosed by biopsy and underwent resection after chemotherapy and radiotherapy. All patients were followed up for 18, 21 and 25 months, respectively. All patients died due to complications such as increased intracranial pressure and hydrocephalus. Conclusions: Neurocutaneous melanosis is a congenital neurocutaneous syndrome caused by abnormal development of embryonic neuroectodermal melanoblasts. Most cases are associated with somatic mutations of NRAS gene. Clinicians should pay attention to the skin manifestations and neuroimaging examination in patients with unexplained intracranial hypertension or epilepsy. The diagnosis of neurocutaneous melanosis depends on histopathology and genetic testing.

Objective: To investigate clinicopathological and molecular genetic characteristics of CD117-positive eosinophilic renal cell tumors (ERCTs) with unusual morphological and immunophenotypic features. Methods: Formalin-fixed, paraffin-embedded tissues from 10 cases (9 cases from Xiangya Hospital, Central South University and 1 case from Bishan Hospital of Chongqing Medical University) of diagnostically challenging CD117-positive ERCTs between January 2017 and October 2024 were collected. Histological reviews were performed on HE-stained sections, followed by immunostaining and whole-exome sequencing (WES). Results: The 10 patients were composed of 4 males and 6 females, with ages ranging from 29 to 57 years, median 49.5 (36.8, 51.8) years. The sizes of tumors ranged from 2.5 to 6.0 cm, median 4.8(2.9,5.2) cm. All 10 ERCTs were composed of variably eosinophilic cells and characterized by prominent morphological features including exclusively eosinophilic (2 cases), focal chromophobe-like (3 cases), prominent nested (2 cases), prominent flocculent cytoplasm (1 case), a collision of renal oncocytoma (RO)/chromophobe renal cell carcinoma (ChRCC) (1 case), and diffusely degenerative atypia (1 case). Immunohistochemically, a subset of 10 tumors variably expressed CK7 (7/10) and vimentin (3/10), while they were all positive for CD117 (10/10), PAX8 (10/10), SDHB (10/10), and FH (10/10) and negative for CAⅨ (10/10) and 2SC (10/10). The Ki-67 proliferation index ranged from 1% to 5%. WES identified a GNAS mutation in one case of the RO/ChRCC collision tumor, while no characteristic mutations of other renal cell tumor types were detected in the remaining 9 cases. The analysis of copy number variations revealed complex karyotypic alterations in 4 tumors, harboring various gain of chromosomes 4, 5, 7, 12, 13, 15, 16, 18, and 22, with 3 cases showing variable loss of chromosomes 1, 2, 6, 10, 13, and 17. These 4 cases were molecularly classified as eosinophilic ChRCC. The remaining 6 cases, including 2 cases with a normal diploid karyotype and 4 cases with slight karyotypic alterations, were molecularly classified as 5 ROs and 1 RO-dominant RO/ChRCC collision tumor. Finally, the original diagnosis was retained in 4 cases and revised in 6 cases. Conclusions: CD117-positive ERCTs with uncertain classification may exhibit various morphological overlaps, non-classic histological features, and aberrant immunophenotypes. Combined immunostaining of CK7, CD117, vimentin, SDHB, FH, and 2SC can greatly help discriminate among these tumors and their mimics. When the diagnosis is challenging based only on morphology and immunohistochemistry, molecular genetic tests may be useful.

Objective: To investigate the clinicopathological features, pathological classification, and molecular characteristics of pulmonary hamartomas. Methods: A retrospective analysis was conducted on 316 cases of pulmonary hamartomas diagnosed at Nanjing Chest Hospital, Nanjing, China from January 2015 to June 2024. Next generation sequencing (NGS) was performed on 15 cases of this study. The clinical data, histopathological features, immunophenotypes, and molecular alterations were analyzed. Relevant literature was reviewed. Results: Among the 316 patients, there were 154 males and 162 females, with an average age of 56±10 years. Among the 316 cases, 310 were intrapulmonary hamartomas and 6 were intraluminal bronchial hamartomas. Microscopically, there were complex proliferative mesenchymal components and epithelial components, presenting various combinations and hamartomatous morphologies. These hamartomas were morphologically classified into mesenchymal-type hamartomas (cartilaginous, fibrous, smooth muscle, adipose tissue, and mixed types) and epithelial-mesenchymal mixed-type hamartomas (respiratory epithelial-mesenchymal mixed and mucosal gland-mesenchymal mixed types). The cartilaginous hamartomas accounted for 72.8% (230/316) of them, and the non-cartilaginous hamartoma accounted for 27.2% (86/316). Secondary changes such as calcification, ossification, collagenization, mucin degeneration, and cystic changes were commonly present. The immunophenotype was CK7+/TTF1+ for respiratory epithelial cells, or TTF1-/CK7+/p40+ for interstitial cells. Interstitial cells might express desmin, SMA, S-100, caldesmon, etc, while CD34+/CD10+/ER+ spindle-shaped interstitial cells were also commonly noted. Genetic variations were detected in 11 of the 15 cases that were subject to NGS, including HMGA2-related fusion genes, EP300 mutations, FLT1 mutations, JAK1 mutations, SETD2 and TAP2 mutations, and high-copy amplification of CDK4/PHF1/TSPAN31. The patients were followed up for 6 to 110 months without any known recurrence or metastasis. Conclusions: Pulmonary hamartomas mainly occur in the peripheral lung parenchyma, with the cartilaginous type being the most common. Their clinical pathological and molecular features of pulmonary hamartomas are characterized and the histological types are roughly ascertained in this study, with emphasis of the key points of diagnosis and differential diagnosis. Classification of pulmonary hamartomas is valuable for guiding future research. Pulmonary hamartomas overall have a good prognosis. However, those with cystic changes or intraluminal hamartomas in the bronchus may cause serious airway lesions and therefore require special attention.

Objective: To investigate the clinicopathological and molecular genetic characteristics of diffuse gliomas with the features of polymorphous low-grade neuroepithelial tumor of the young (PLNTY) and their prognostic values. Methods: A retrospective analysis was performed on 14 cases of diffuse gliomas with PLNTY features diagnosed at the First Affiliated Hospital of Fujian Medical University, Fuzhou, China from June 2020 to August 2024. Their clinicopathological characteristics were examined, and their molecular genetic and epigenetic features were assessed using next-generation sequencing (NGS) and methylation analysis. Factors influencing prognosis were also analyzed. Results: Among the 14 patients, there were 8 males and 6 females, aged 3-62 years, median 29 (9, 50) years. All cases were initially diagnosed as low-grade diffuse gliomas histologically but exhibited the histological and immunohistochemical features of PLNTY. At the molecular level, all cases showed molecular abnormalities involving the mitogen-activated protein kinase pathway, including 5 cases with FGFR3-TACC3 (F3T3) fusion, 3 cases with FGFR2 fusion, 5 cases with BRAF V600E mutation, and 1 case with FGFR1 mutation. Among them, TERT promoter mutations were frequently observed in tumors with F3T3 fusion (5/5), while NCOR2 in-frame insertion mutations were prominent in tumors with non-F3T3 fusions. Clinical follow-up showed recurrence in 3 cases, all of which had F3T3 fusion and concurrent TERT promoter mutations. Prognostic analysis confirmed that F3T3 fusion with concurrent TERT promoter mutation was associated with poor prognosis. Conclusions: Diffuse gliomas with PLNTY features exhibit heterogeneity in clinicopathology and molecular genetics, with FGFR3/FGFR2 fusions and BRAF/FGFR1 mutations as the most common molecular alteration. They often have concurrent F3T3 fusion and TERT promoter mutations, which are related to poor prognosis. The possibility of molecular glioblastoma should be considered for these tumors. It is thus recommended to perform genetic testing on diffuse gliomas with PLNTY features in order to facilitate integrated diagnosis and provide molecular evidence for accurate evaluation of prognoses.

Objective: To investigate the clinicopathological characteristics and genetic alterations of undifferentiated embryonal sarcoma of the liver (UESL). Methods: Three cases of UESL diagnosed in the Department of Pathology, the Third Affiliated Hospital of Sun Yat-sen University from 2020 to 2023 were retrospectively collected. The clinical, histomorphological, immunohistochemical, and genetic profiles were reviewed and analyzed. Results: The cohort comprised of three patients, including one male and two females, aged 7, 9, and 15 years, respectively. Tumor locations were in the right lobe of the liver in two cases, and in both the right and left lobes in one case. One case exhibited tumor rupture with hemorrhage. Gross examination revealed solid tumors in gray-red fleshy appearance, with areas of hemorrhage and necrosis. Microscopically, the tumor was composed of irregularly shaped spindle and polygonal cells arranged in bundles or sheets with varying density, scattered within a myxoid matrix containing giant tumor cells and eosinophilic globules. The tumor cells were positive for Vimentin, CD56, CD68, and bcl-2, with a Ki-67 index of 30%-80%. INI1 expression was retained, while p53 exhibited a mutant pattern. CKpan, CK7, CK19, EMA, HepPar-1, Arginase-1, AFP, CD34, S-100, Myogenin, and MyoD1 were negative. All three cases harbored TP53 missense mutations. Case 1 also showed MDM2 copy number amplification (class Ⅰ mutation), and case 2 exhibited a frameshift mutation in exon 10 of TSC2 (class Ⅱ mutation). Additionally, several class Ⅲ mutations were identified in all three cases. Germline testing for tumor-related genetic variants in case 2 revealed a missense mutation in exon 12 of DICER1, an in-frame insertion mutation in exon 8 of MSH2, and a missense mutation in exon 30 of TSC2. Conclusion: UESL is a rare malignant mesenchymal tumor of the liver, predominantly affecting children, with distinctive clinicopathological features and genetic alterations. TP53 mutations may play a key role in the pathogenesis of this tumor.

In the past decade, breast pathology in China has made significant progress in diagnostic standards, technological applications, scientific research, and discipline development. The histopathological diagnostic system has been continuously refined, with the implementation of relevant guidelines and expert consensus enhancing standardization and reproducibility of diagnostic results. Immunohistochemistry and molecular testing technologies have become increasingly sophisticated, with emerging biomarkers such as low HER2 expression and PIK3CA mutations gradually integrated into clinical decision-making, promoting the advancement of precision therapy. The application of digital pathology and image-assisted analysis has steadily expanded, providing new tools to improve diagnostic efficiency and consistency. The national breast pathology group has actively advanced the development of tiered diagnostic systems, workforce training, and public education, effectively strengthening diagnostic capabilities at the grassroots level. Looking ahead, the integration of multidimensional data, optimization of auxiliary diagnostic systems, and interdisciplinary collaboration are expected to drive the continued development of breast pathology in China.

Pediatric tumors differ significantly from adult cancers, possessing unique developmental origins, histological features, and molecular genetic changes. With the rapid advancement of multi-omics technologies, such as genomics, transcriptomics, proteomics, and epigenetic analyses, the molecular characteristics of pediatric tumors have been extensively revealed, providing new possibilities for precision medicine. Concurrently, the integration of artificial intelligence and digital pathology has effectively enhanced diagnostic accuracy, presenting a broad scope for future development. While this progress positively impacts the pathological diagnosis of pediatric tumors, it also presents challenges related to data complexity, technology integration, and the promotion of clinical applications. This article aims to discuss the influence of molecular and artificial intelligence, as well as multimodal integrated pathological models on diagnosis and prognostic prediction of pediatric tumor, with the goal of fostering further exploration and in-depth research.

This study aimed to explore the biological functions and clinical value of mothers against decapentaplegic homolog (SMAD) 7 in head and neck squamous cell carcinoma (HNSCC) through bioinformatics analysis and basic experiments.

The v-Raf murine sarcoma viral oncogene homolog B (BRAF) gene is one of the most critical proto-oncogenes and functions as a key regulator in the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway. The incidence of BRAF mutations in non-small cell lung cancer (NSCLC) patients ranges from 1.5% to 5.5%, with BRAF V600 mutations accounting for approximately 30%-50% of all BRAF mutations, among which BRAF V600E represents the most prevalent mutation type. Currently, the combination of Dabrafenib and Trametinib has been recommended as first-line therapy for BRAF V600-mutant NSCLC by multiple domestic and international guidelines including National Comprehensive Cancer Network (NCCN), European Society of Medical Oncology (ESMO), and Chinese Society of Clinical Oncology (CSCO). However, there are no clear targeted treatment recommendations for BRAF non-V600 mutations. Although case reports suggest that Dabrafenib combined with Trametinib may be effective for patients with BRAF non-V600 mutations, the efficacy and safety require further validation due to limited sample size and lack of large-scale clinical trial data. This article reports a case of NSCLC with a rare BRAF insertion and deletion mutation that responded well to the treatment of Dabrafenib in combination with Trametinib, aiming to enhance clinicians' understanding of such NSCLC cases with extremely rare mutation and provide a reference for future treatment strategies.
.

Human epidermal growth factor receptor 2 (HER2) mutations play a role as a driver gene in non-small cell lung cancer (NSCLC). Patients with advanced NSCLC harboring HER2 mutations exhibit poor responses to conventional chemotherapy and immunotherapy, hence targeted therapies against HER2 are under extensive investigation. This review analyzes the biological characteristics of HER2, an overview of clinical trials for targeted therapy drugs, including monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and antibody-drug conjugate, and research directions for drug resistance in NSCLC. Currently, Pyrotinib and Trastuzumab deruxtecan have been approved for the treatment of advanced NSCLC with HER2 mutations, suitable for patients who have failed standard therapy, which is far from meeting the clinical demands. Novel selective HER2 TKIs are gradually emerging. Future exploration trends are gradually shifting from single drugs to combination strategies, and are exploring more precise selection strategies as well as research on resistance mechanisms. These studies will provide a theoretical basis for clinical treatment strategies for advanced NSCLC with HER2 mutations, promoting the development of personalized therapy.
.

Lung cancer stands as the primary cause of cancer-related mortalities globally, presenting a severe menace to human health. In individuals with non-small cell lung cancer (NSCLC), Kirsten rat sarcoma viral oncogene (KRAS) mutations serve as crucial oncogenic drivers. NSCLC with KRASG12C mutation is among the most prevalent subtypes. Currently, the detection methods for KRAS mutations predominantly concentrate on polymerase chain reaction (PCR) and sequencing platforms. The diverse derivative technologies of these two platforms each exhibit distinct merits and demerits in terms of testing performance and detection throughput, and find significant applications in tissue biopsy and liquid biopsy. In targeted therapies, KRASG12C targeted drugs, including Sotorasib, Adagrasib, Fulzerasib, Garsorasib, and Glecirasib, have demonstrated certain therapeutic efficacies in clinical trials and have obtained marketing approval. To tackle drug resistance and enhance patient's prognoses, combination therapeutic strategies that integrate targeted agents with chemotherapy, immune checkpoint inhibitors, Src homology region 2 domain-containing phosphatase 2 (SHP2) inhibitors, and epidermal growth factor receptor (EGFR) monoclonal antibodies have emerged. This paper systematically reviews the advancements in the diagnosis and targeted therapy of NSCLC with KRASG12C mutation, aiming to offer a reference for the selection of clinical treatment regimens and subsequent research.
.

The incidence of leptomeningeal metastasis (LM) in patients with advanced non-small cell lung cancer (NSCLC) is increasing gradually. However, it poses therapeutic challenges due to limited effective interventions. Intrathecal Pemetrexed (IP) holds broad application prospects in the therapeutic domain of LM. This study aims to evaluate the efficacy, safety, and optimal combination strategies of IP in NSCLC-LM patients with epidermal growth factor receptor (EGFR) mutation-positive status, with the aim of providing real-world data support for exploring more precise personalized treatment strategies for these patients.

Objective:Proteins are closely associated with the development, progression, and immunotherapy of head and neck squamous cell carcinoma（HNSCC）. However, few clinical models utilize proteomics to predict prognosis and immunotherapy efficacy. In this study, we developed a protein prognostic model（PPM） to stratify survival outcomes and differential immunotherapy responses in HNSCC patients. Methods:Based on proteomic profiling, we constructed a PPM comprising 11 protein markers. Patients were classified into high-and low-risk groups according to PPM scores. The prognostic value of risk scores was evaluated using Cox regression analysis, and predictive accuracy was assessed via time-dependent receiver operating characteristic（ROC） curves. Additionally, we analyzed treatment responses to PD1/CTLA4 immunotherapy in PD1-or CTLA4-positive patients across risk groups. Results:Cox regression confirmed the risk score as an independent prognostic factor（HR=1.161, 95%CI 1.112-1.213, P<0.001）, with high-risk patients exhibiting significantly poorer survival than low-risk counterparts. The model demonstrated robust predictive accuracy, with 1-year and 3-year time-dependent ROC areas under the curve（AUC） of 0.713 and 0.707, respectively. In PD1/CTLA4-positive subgroups, low-risk patients showed superior immunotherapy responses compared to high-risk patients. Conclusion:The PPM can provide reliable prognostic stratification and preliminary guidance for immunotherapy in HNSCC. However, further clinical studies and basic experiments are needed for further verification.

Rectal cancer is one of the most common malignant tumors in China, with more than half of patients diagnosed at the locally advanced stage. Currently, the standard treatment for locally advanced rectal cancer (LARC) primarily involves neoadjuvant chemoradiotherapy followed by radical surgery. The advent of immune checkpoint inhibitors has revolutionized the neoadjuvant treatment landscape for mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) rectal cancer. However, most rectal cancer patients exhibit mismatch repair-proficient/microsatellite stable (pMMR/MSS) status and show poor responsiveness to immunotherapy. In recent years, multiple studies have demonstrated that neoadjuvant short-course radiotherapy followed by chemotherapy and immunotherapy can improve the pathological complete response rate in pMMR/MSS LARC patients. Nevertheless, controversies persist regarding patient selection, efficacy evaluation, adverse event management, postoperative adjuvant therapy, and follow-up strategies. Considering the Colorectal Surgery Group of the Surgery Branch of the Chinese Medical Association, in collaboration with the Colorectal and Anal Surgery Committee of the Chinese Research Hospital Association, the Chinese Colorectal Cancer Clinical Research Collaborative Group, and related experts, has developed this consensus document by referencing domestic and international research advancements. The aim is to provide standardized guidance for the clinical application of this treatment approach.

To investigate the association of HOTAIR gene rs920778 single nucleotide polymorphism (SNP) with breast cancer susceptibility and response to HER2-targeted therapy in a Chinese population.

To investigate the prognostic significance of PDZ-binding kinase (PBK) in pan-cancer and its potential as a therapeutic target for pancreatic cancer.

To evaluate the regulatory effects of lncRNA LINC00261 on proliferation, invasion, and metastasis of esophageal squamous cell carcinoma (ESCC) cells.