A 3-month-old female infant was admitted for incessant crying for 3 days. Examination revealed a rapidly growing massive retroperitoneal mass that was difficult to resect. Needle biopsy confirmed infantile fibrosarcoma. Initial chemotherapy with the VAC regimen (vincristine, actinomycin D, and cyclophosphamide) was administered, but the response was poor. The common fusion in infantile fibrosarcoma is ETV6-NTRK3, and next-generation sequencing detected an RBPMS-NTRK3 gene fusion in this patient. To our knowledge, this is the first reported case of infantile fibrosarcoma with RBPMS-NTRK3 fusion in China. Treatment with larotrectinib resulted in marked tumor shrinkage.

To explore the effects and the molecular mechanisms of homo sapiens longevity assurance homolog 2 of yeast LAG1(LASS2) dephosphorylation on the biological functions of prostate cancer cells.

To analyze the acupoint selection patterns and core prescriptions of acupuncture for polycystic ovary syndrome (PCOS) using data mining, and to explore the molecular mechanisms of core acupoints through network acupuncture medicine.

To investigate the expression patterns and prognostic value of lipid metabolism-related genes in breast cancer.

Objective: To investigate the clinical values of fluorescent PCR-capillary electrophoresis (PCR/CE) for detecting somatic mutations in the proofreading exonuclease domain of DNA polymerase epsilon (POLE-exo*) in endometrial carcinomas (EC), as compared with Sanger sequencing. Methods: A total of 280 EC cases diagnosed at the Department of Pathology at Peking University Third Hospital, Beijing, China from December 2022 to December 2023 were collected. Ten cases, which had previously been confirmed to harbor POLE pathogenic mutations through next-generation sequencing (NGS), were excluded. Subsequently, parallel sequencing using both PCR/CE and Sanger sequencing methods was conducted on the remaining 270 EC samples without prior POLE testing, aiming to examine 11 known pathogenic mutation-sites located within exons 9, 11, 13, and 14 of the POLE gene. NGS was then carried out on the EC cases in which the PCR/CE and/or Sanger sequencing results indicated the presence of POLE-exo*. Results: Among the 270 EC samples, POLE-exo* was detected in 4 cases (4/270, 1.5%) using Sanger sequencing. In contrast, the PCR/CE identified POLE-exo* in 12 cases (12/270, 4.4%). It was noteworthy that all cases in which POLE-exo* was detected through Sanger sequencing were also successfully identified using PCR/CE (4/4, with a detection rate of 100%). These results were further verified by NGS. The PCR/CE also uncovered an additional 8 cases (8/266, 3.0%) of POLE-exo* in the 266 samples that were negative for POLE mutations per Sanger sequencing. Of these 8 cases, 4 were validated using NGS, exhibiting variant allele frequency (VAF) below 10%, but tumor mutation burdens exceeding 10 mutations per megabase. However, due to small tumor sizes, NGS verification could not be performed on the remaining 4 PCR/CE-positive but Sanger-negative cases. Conclusion: The PCR/CE exhibits better sensitivity and detection capabilities than the Sanger sequencing in identifying POLE-exo* in EC samples, particularly in detecting low VAF.

Objective: To investigate the clinicopathological characteristics of ossifying fibromyxoid tumor (OFMT) with rare fusion subtypes. Methods: Three cases of OFMT with rare fusion subtypes, diagnosed and consulted in the Zhejiang Hospital, Zhejiang Provincial People's Hospital, Hangzhou, China and Ningbo Clinical Pathology Diagnosis Center, Ningbo, China from January 2016 to December 2024 were collected. Immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and targeted RNA sequencing were performed to analyze the immunohistochemical and molecular genetic characteristics of these OFMT. Literature review was also conducted. Results: All three patients were male, with ages of 50, 74, and 58 years, respectively. The tumors were located in the left foot, left thigh, and left lumbar region, respectively, and all presented as slowly growing, painless masses in the skin or subcutaneous tissue. Grossly, the tumors measured 3.5 cm, 6.3 cm, and 5.0 cm in maximum diameter, respectively, with a grayish-white to grayish-yellow, solid, lobulated cut surface. One case exhibited a noticeable myxoid texture. Microscopically, one tumor was located in the superficial dermis, while the other two were in the subcutaneous tissue. The tumors were well-demarcated and showed a lobulated or multinodular growth pattern. None of the cases had a complete surrounding bony shell (only one case had very focal ossification). The tumor cells were monomorphic, short spindle-shaped, oval to epithelioid, and arranged in solid sheets, trabeculae, and small nests within a variably fibromyxoid stroma. Case 1 exhibited abundant pseudorosette-like structures formed by short spindle cells surrounding acellular fibrous stroma. Case 2 showed focal transition of epithelioid tumor cells into fasciculately arranged spindle cells, with extensive stromal hyalinization. Case 3 had a predominantly myxoid stroma with a rich network of thin-walled blood vessels. The tumor cells exhibited mild nuclear atypia with 1-3 mitotic figures per 50 high-power fields. All three cases showed diffuse and strong expression of CD10. Two of the three cases showed nuclear expression of TFE3, while one case showed diffuse and strong expression of desmin and S-100. Targeted RNA sequencing revealed PHF1 (ex12)::TFE3 (ex7) fusion in two cases and MEAF6 (ex5)::PHF1 (5'UTR) fusion in one case, which were further confirmed by FISH study. All three patients underwent tumor resection. Two showed no recurrence during follow-up periods of 98 months and 15 months, respectively, while one experienced local recurrence at 12 months postoperatively. Conclusions: OFMT with rare fusion subtypes often exhibits atypical histological and immunophenotypic features, and lacks a characteristic bony shell. Incorporating TFE3 into the diagnostic IHC panel greatly aids in screening for the cases with rare PHF1::TFE3 fusions. Familiarity with the histological and immunophenotypic characteristics, and differential diagnostic points of these rare OFMT subtypes, is essential for judicious use of molecular genetic tools in achieving a definitive diagnosis.

Objective: To investigate the clinicopathological and molecular genetic characteristics of pediatric tumors with DICER1 mutations. Methods: A total of 90 patients diagnosed with various types of pediatric tumors at Beijing Children's Hospital, Capital Medical University, Beijing, China from July 2023 to September 2025 were included in this study. PCR amplification and Sanger sequencing were performed to detect the coding-region mutations of the DICER1 gene. The clinical, histopathological, and molecular genetic features of the cases with DICER1 mutation were then analyzed. Results: Among the 90 patients, 39 were male and 51 were female, with an age of onset ranging from 1 month to 17 years [median 7.13 (2.77, 10.37) years]. DICER1 mutations were detected in 37 patients (37/90, 41.1%). Among them, 9 cases harbored one mutation [6 pleuropulmonary blastomas (PPBs), 2 sex cord stromal tumors (SCSTs), and 1 cystic nephroma (CN)], 27 cases carried two mutations [10 PPBs, 3 anaplastic sarcomas of the kidney (ASKs), 3 SCSTs, 3 thyroid adenoma, 2 nodular thyroid goiters, 2 thyroid follicular lesions, 2 CN, 1 embryonal rhabdomyosarcoma, and 1 case with multiple primary tumors], and 1 case exhibited three mutations (bilateral ASKs). Despite variations in the site of origin, DICER1-mutant tumors shared several morphological features. Grossly, they presented as multilocular cystic, cystic-solid to solid masses. Microscopically, they exhibited a subepithelial layer of mesenchymal cells, with focal rhabdomyoblastic/chondroid/chondrosarcomatous differentiation, as well as cellular anaplasia. Germline testing using peripheral blood in the 31 patients with DICER1 mutation confirmed germline origin in 61.3% (19/31) of them. Parental analysis (n=12) demonstrated genetic inheritance in 8 cases, predominantly from families with tumor history. Germline variants scattered throughout DICER1 and consisted of loss-of-function mutations (nonsense, frameshift, and splice-site). Somatic mutations showed distinct clustering in exons 24 and 25 hotspots (codons 1705, 1709, 1809, 1810 and 1813), primarily missense variants. Notably, one multiple primary tumor case harbored a somatic mosaic p.E1705K mutation. Conclusions: DICER1 mutations are frequently detected in pediatric PPB, CN, SCST, ASK, nodular thyroid goiter, thyroid adenoma, and genitourinary rhabdomyosarcoma, which often represent as the index case of DICER1 syndrome. Performing DICER1 mutation testing in these patients not only facilitates tumor diagnosis and secondary cancer surveillance, but also enables the comprehensive genetic risk assessment and management for patient's family members.

Objective: To investigate the clinicopathological features, diagnosis, and prognosis of renal solitary fibrous tumor (SFT). Methods: Five cases of renal SFT with unequivocal diagnoses at the Affiliated Hospital of Qingdao University between January 2011 and July 2025 were subject to analyses of their clinical, morphological, immunophenotypic, and molecular characteristics, accompanied by a literature review. Results: Two males and three females aged between 45 and 62 years were included, all of whom presented with the discovery of a renal mass during routine physical examinations. Gross examination showed that the five tumors were all confined in the kidney. The tumors were nodular with maximum diameters ranging from 2.5 cm to 11.0 cm (mean, 5.8 cm). Upon cross-sectioning, they exhibited gray-white or gray-yellow cut surface. Histologically, the tumor cells exhibited oval or short spindle shapes in four cases, presenting with varying densities and arranged in short bundles, woven patterns, and irregular formation. Various amounts of coarse collagen and scattered staghorn blood-vessels were found in the stroma. In one case (case 5), the tumor cells were long spindle-shaped, densely organized in bundles, and interwoven, exhibiting inconspicuous boundaries, moderate nuclear atypia, and at least 4 mitotic figures per 10 high-power fields. Irregular patchy collagen deposition was particularly prominent at the edges of the tumor tissue. In two cases (cases 3 and 5), scattered and various amounts of renal tubules were observed in the tumor. Two cases (cases 4 and 5) demonstrated focal invasion of the renal parenchyma, although no necrosis was noted. Immunohistochemical staining showed that the tumor cells were diffusely and strongly positive for vimentin and STAT6 in all 5 cases, and positive for CD34. Bcl-2 positivity was present in 4 of the 5 cases. All cases were negative for CKpan, EMA, PAX8, HMB45, Melan A, SMA, and S-100 protein. The p53 status was wild type, and the Ki-67 index ranged from 1% to 8%. Next-generation sequencing was conducted on one case (case 4), revealing the NAB2 (exon 3)::STAT6 (exon 18) gene fusion. The 5 patients were followed up for 1 to 158 months (mean, 56 months), and all were alive with no recurrence or metastasis. Conclusions: SFT of the kidney are rare and morphologically similar to extrarenal SFT. Key morphological features include short spindle-shaped tumor cells arranged in bundles, interwoven patterns or irregularly, accompanied by staghorn blood-vessels and scattered coarse hyaline collagen fibers. SFT with epithelial inclusions may represent a relatively common histological subtype in the kidney. Immunohistochemical staining that demonstrates diffuse and strong positivity for STAT6 and CD34 is instrumental in diagnosing this tumor. The pathogenesis is linked to the centromeric inversion of chromosome 12q, resulting in the fusion of the NAB2 and STAT6 genes. Most of these tumors exhibit favorable prognosis.

Objective: To investigate the clinicopathological characteristics and diagnostic criteria of cutaneous melanocytic tumor with CRTC1::TRIM11 fusion (CMTCT), and to improve understanding of this entity. Methods: The clinical features, histology, immunohistochemistry (IHC) and molecular characteristics of 3 CMTCT cases were analyzed, supplemented by a literature review. Results: All patients were female, aged 53, 46 and 46 years, respectively. Grossly, the lesions presented as dermal/subcutaneous nodules protruding from the skin surface. Histologically, tumor cells were arranged in nested and fascicular patterns separated by delicate fibrous septa. Tumor cell infiltration was observed in the epidermis of case 1, but not in that of cases 2 and 3. Tumor cells exhibited epithelioid, spindle-shaped, or oval morphology, with eosinophilic or pale cytoplasm and mild to moderate nuclear atypia. Tumor mitotic figure was <5/10 HPF. Scant melanin pigment was observed in case 2. IHC demonstrated diffuse and strong positivity for SOX-10, S-100 protein and MITF. HMB45 was negative in two cases (case 1 and case 3) and focally positive in case 2; Melan A was negative in two cases (case 1 and case 3) and partially positive in case 2. The Ki-67 proliferation index was approximately 5%-8%. Molecular analysis revealed CRTC1::TRIM11 fusion in three cases via RNA sequencing, and CRTC1 rearrangement in two cases (case 1 and case 3) via fluorescence in situ hybridization. Conclusions: CMTCT shares histological and immunophenotypic features with melanoma and clear cell sarcoma but is defined by the presence of CRTC1::TRIM11 fusion, necessitating molecular confirmation for definitive diagnosis. Complete excision with clear margins is recommended. While most of the CMTCTs exhibit indolent biological behaviors, rare cases may recur locally or metastasize, warranting close follow-up.

After the release of the guideline for HER2 testing in breast cancer (2024 version), in order to improve the implementation of the guidelines, the Chinese Breast Pathology Group conducted a nationwide survey, gathering feedback from pathologists across China. Based on this, we analyzed and summarized seven key issues commonly encountered in pathological practice. These issues include the heterogeneity of HER2 protein and gene expression, reporting of HER2-ultralow, testing and interpretation issues of HER2 low-level expression, the establishment of external controls for HER2 testing, the interpretation standards for rare staining patterns, and the role of new technologies in HER2-low expression testing. These findings reflect the effectiveness and challenges in the implementation of the guidelines and provide valuable insights for the further optimization of the HER2 testing guidelines in the future.

To retrospectively analyze the clinical data of 465 newly diagnosed patients with multiple myeloma (NDMM) admitted to the First Affiliated Hospital of Nanjing Medical University from December 2016 to December 2024, and compare the prognostic value of high-risk cytogenetic abnormalities (HRCAs) in NDMM patients under mSMART 3.0 and mSMART 4.0 risk stratification systems. The results showed that in both stratification systems, the prognosis of high-risk patients was worse than that of standard-risk patients. Moreover, a higher number of HRCAs was associated with a worse prognosis. The mSMART 4.0 system, which considers the coexistence of various cytogenetic abnormalities, provides a more precise definition of HRCA than mSMART 3.0. It demonstrates a superior ability to differentiate between different categories of cytogenetic risk.

Objective: To evaluate the clinical value of peripheral blood monocyte subset analysis in the diagnosis and treatment of chronic myelomonocytic leukemia (CMML) . Method: We retrospectively enrolled 51 patients newly diagnosed with CMML at Guangdong Provincial People's Hospital between June 1, 2020, and December 31, 2024, according to the WHO 2022 diagnostic criteria. Twenty-three patients with other myeloid neoplasms (excluding CMML) and peripheral monocytosis (absolute count ≥0.5×10(9)/L and percentage ≥10%) were included as the control group. All patients underwent bone marrow aspiration for examinations including bone marrow smears, biopsies, cytogenetics, and gene mutation analysis to establish a definitive diagnosis. Concurrently, flow cytometry was used to determine the proportions of peripheral blood monocyte subsets: classical (MO1, CD14(+)CD16(-)) , intermediate (MO2, CD14(+)CD16(+)) , and non-classical (MO3, CD14(low)CD16(+)) . Differences between the groups were compared, and diagnostic efficacy was evaluated using receiver operating characteristic (ROC) curves. Result: Among the 51 CMML patients, the proportion of the peripheral blood MO1 subset was significantly higher than that in patients with other myeloid neoplasms (P=0.027) , whereas there were no significant differences in the MO2 and MO3 subsets (all P>0.05) . Further analysis revealed that 43 (84.31%) of the CMML patients met the WHO diagnostic threshold for the MO1 subset (≥94%) , while the remaining 8 patients did not; 46 patients (90.20%) had MO3 subset proportions below the threshold proposed by Hudson (≤1.13%) , while the remaining 5 patients were above this threshold. In-depth analysis showed that among the 8 patients who did not meet the WHO criteria, 7 were experiencing inflammation. Similarly, all 5 patients who did not meet the Hudson criteria were in an inflammatory state. Subsequent ROC curve analysis of this cohort identified a cut-off value for the MO1 subset of 97.55% [Area Under the Curve (AUC) =0.661, P=0.027], which aligns with the WHO criteria. Conclusion: Peripheral blood monocyte subset analysis, particularly MO1 subset analysis, can effectively assist in CMML diagnosis, but exclusion of inflammatory conditions is required.

To investigate the role of PTEN-induced putative kinase 1 (PINK1) in regulating the viability, migration, and apoptosis of colorectal cancer (CRC) cells, and to explore its potential epigenetic mechanisms.