American journal of clinical pathology最新文献

Objective: To describe the prevalence and clinicopathologic associations of FGFR-altered urinary tract carcinomas in institutions incorporating reflex testing.

Methods: Next-generation sequencing was prospectively performed on urinary tract carcinomas for the detection of FGFR1-4 alterations at 2 tertiary care centers (2021-2025), using the Oncomine Comprehensive Assay (OCA) v3 DNA and OCA Plus RNA. Reflex testing was conducted on metastatic and/or advanced (pT3/4) carcinomas.

Results: The cohort included 366 patients (239 lower tract carcinomas, 72 upper tract carcinomas, and 55 metastases). Median age was 72.5 years (range, 36-97). Fifty-nine (16.1%) tumors were FGFR-altered. Forty-nine (13.4%) patients with actionable FGFR alterations (33 FGFR3 mutations, 13 FGFR3 fusions, and 3 FGFR2 mutations) were all 55 years or older (P = .097). The prevalence of actionable FGFR alterations was significantly higher in upper vs lower tract carcinomas (23.8% vs 13.8%, P = .007) and in lung metastases vs other metastatic sites (57.1% vs 10.4%, P = .002). A higher frequency was also seen in metastases vs primary tumors (16.4% vs 12.9%), although this difference did not reach statistical significance (P = .482). Actionable FGFR alterations were observed in urothelial carcinoma not otherwise specified (40/261) and in urothelial carcinoma with squamous differentiation (6/43), micropapillary features (2/11), or nested features (2/7).

Conclusions: The detection rate for FGFR1-4 alterations in a real-world, dual-institution cohort of urinary tract carcinomas was reported.

Objective: Gastrointestinal (GI) symptoms are common in systemic mastocytosis (SM). We hereby report the clinicopathologic and molecular features of GI mastocytosis.

Methods: The study includes 104 patients with suspected SM. Of 258 GI biopsy -specimens, 33 (20 patients, 19%) were mastocytosis-positive, with 19 (16 patients) initially missed.

Results: Tryptase (n = 29) was weakly positive/negative in two-thirds of the mastocytosis-positive GI biopsy specimens. Additional immunohistochemistry (n = 23) showed positive mast cell expression for CD30 (n = 2), CD123 (n = 7), and PD-L1 (n = 12), as well as increased PD-1-positive cells (n = 4). Sixty patients had positive bone marrow (BM) for SM (SM-BM+), including 19 with positive GI biopsy specimens (SM-GI+). Almost all (43/44) SM-BM- patients were SM-GI-. The SM-GI vs SM-BM status showed high positive predictive value (95%) and specificity (98%). Patients with SM with mastocytosis-positive vs mastocytosis-negative GI biopsy specimens had higher serum tryptase levels (P = .04). KIT D816V mutation was detected in 7 of 13 and 12 of 13 mastocytosis-positive GI biopsy specimens using allele-specific polymerase chain reaction and droplet digital polymerase chain reaction (ddPCR), respectively.

Conclusions: GI mastocytosis is highly predictive of SM in BM; however, most SM-BM+ patients are SM-GI-. The SM-BM- patients are very unlikely to be SM-GI+. Because GI neoplastic mast cells are often tryptase negative, diagnostic evaluation should include CD117 and CD25 immunohistochemistry, as well as KIT D816V mutation analysis by ddPCR as needed.

Objective: To develop and validate a machine learning model for predicting oligoclonal band (OCB) positivity using routine cerebrospinal fluid (CSF) and serum biochemical markers to improve the diagnostic accuracy and efficiency of assessing intrathecal immunoglobulin G (IgG) synthesis.

Methods: In this retrospective study (n = 1709), an ensemble model was developed using 8 refined CSF and serum parameters. Combining optimized CatBoost, XGBoost, and LightGBM classifiers, the model was trained and evaluated using a 2-phase workflow, including 5-fold cross-validation and validation on independent internal (n = 342) and external (n = 49) cohorts.

Results: The developed ensemble model achieved a receiver operating characteristic-area under the curve (ROC-AUC) of 0.902 on the internal test set, significantly outperforming the conventional IgG index (ROC-AUC, 0.795). At its optimal threshold, the model demonstrated an accuracy of 0.830, with a sensitivity of 0.714 and a specificity of 0.916. On the external validation cohort, it achieved 90% accuracy and 96% sensitivity.

Conclusions: A novel machine learning ensemble model accurately predicts OCB positivity using routine laboratory data and demonstrates superior performance compared with the IgG index. This approach represents a significant step in applying artificial intelligence in laboratory medicine, with the potential to enhance diagnostic efficiency. Prospective, multicenter validation is essential for broader clinical implementation.

Objective: The OrganOx metra is a recent innovation approved by the US Food and Drug Administration that enables continuous ex vivo perfusion of a donor liver prior to transplantation. A mixture of human blood products, added nutrients, and drugs is perfused throughout the liver to sustain its viability. This study determines whether the perfusate matrix affects the analytical accuracy of biochemical parameters used to evaluate the function of the donor liver before transplantation.

Methods: A mixing study was conducted to evaluate the percent recovery of total bilirubin, aspartate aminotransferase, alanine aminotransferase, lactic acid, glucose, and lactate dehydrogenase in OrganOx metra perfusate using the Beckman Coulter AU5800 automated platform. Perfusate pools were mixed with pooled patient plasma (Li Hep) in the following ratios: 1:4, 1:1, and 4:1. These mixtures were measured alongside straight patient plasma and straight perfusate.

Results: Agreement between expected and measured values, with a percent recovery for all tested analytes, was between 92% and 109%. Detrimental matrix effects were not observed.

Conclusions: The Beckman Coulter AU5800 analyzer provides reliable and accurate biochemical analysis of OrganOx metra perfusate during ex vivo preservation. The findings validate its suitability for perfusate analysis, supporting its potential use in clinical and research settings.

Objective: β-Catenin-mutated hepatocellular adenomas (HCAs) carry an increased malignant transformation risk and are screened by interpreting glutamine synthetase (GS) and β-catenin by immunohistochemistry (IHC). Our study aims to assess GS and β-catenin interpretation guidelines for applicability and reproducibility in predicting high-risk HCA and other relevant molecular alterations.

Methods: Hematoxylin and eosin (H&E), β-catenin, GS, and CD34 stains from 75 HCAs were interpreted by three pathologists using Method A (GS interpretation: negative, perivenular patchy, map-like, diffuse, and indeterminate) and Method B criteria (similar GS interpretation scheme based on a recent publication, with and without CD34 expression patterns). Ease of application and interpretation confidence level were assessed. High-risk IHC was defined as nuclear β-catenin and/or diffuse homogeneous GS. Molecular testing was performed on a subset of HCAs and controls.

Results: There were 57 resections and 18 biopsy specimens examined. Methods A and B (GS only) were rated as easy to apply, with high interpretation confidence (≥90% using both methods). Consensus rate was comparable in biopsy specimens (100% for both methods) and resections (88% for Method A, 93% for Method B). While the same cases were stratified into high-risk GS categories using both systems, clinically significant genetic alterations (TERT promoter, EGFR, MTOR, and TP53) were identified in 25% of cases stratified as not high risk by IHC.

Conclusions: Both methods have a similar ease of application and level of interpretation confidence, and they also detected β-catenin mutations as expected. Other relevant molecular alterations associated with risk of neoplastic progression and/or bleeding were detected in 25% of HCAs with the non-high-risk IHC phenotype, suggesting the value of molecular testing in this subset.

Objective: Breast cancer is a leading malignancy among women worldwide. Mitotic regulation proteins such as POC1A and NUF2 have been linked to tumor aggressiveness.

Methods: This retrospective study evaluated the immunohistochemical expression of POC1A and NUF2 in 136 cases of invasive ductal carcinoma (IDC), 96 matched metastatic lymph nodes, and 48 adjacent normal breast tissues using Ki-67 as a supporting proliferation marker. Associations with clinicopathologic features were assessed, and survival analyses were conducted using Kaplan-Meier and Cox regression models.

Results: POC1A and NUF2 were significantly overexpressed in tumor tissues compared to normal tissues (P < .001). High expression levels were associated with larger tumor size, higher grade and stage, lymphovascular invasion, distant metastasis, hormone receptor negativity, triple-negative breast cancer (TNBC), and poor Nottingham Prognostic Index scores. Both markers were significantly associated with lymph node involvement. Ki-67 expression also correlated positively with POC1A and NUF2 coexpression (r = 0.574; 95% CI, 0.449-0.677; P < .001). Multivariate analysis identified POC1A as an independent predictor of poor overall survival (OS) (hazard ratio, 2.102; 95% CI, 1.41-3.13; P < .001). Coexpression of POC1A and NUF2 was linked to significantly worse prognosis.

Conclusions: High expression levels of POC1A and NUF2 were significantly associated with aggressive clinicopathologic features and poorer prognosis in IDC. Their correlation with Ki-67 and enrichment in TNBC highlight their potential as prognostic markers and predictors of nodal metastasis. Importantly, POC1A expression was independently associated with worse OS in IDC, including TNBC. While not yet directly actionable, our findings nominate POC1A as a promising independent prognostic biomarker that could potentially refine risk stratification in IDC, particularly for aggressive subtypes like TNBC. However, prospective validation in larger cohorts is mandatory before any clinical application.

Objective: To characterize the clinicopathologic, immunohistochemical, and molecular features of 2 new cases of xanthomatous giant cell renal cell carcinoma, a rare TSC2/MTOR-altered renal neoplasm.

Methods: Both tumors underwent histologic evaluation, immunohistochemical profiling, and DNA-based targeted next-generation sequencing. Fluorescence in situ hybridization for TFE3 rearrangement was performed in 1 case.

Results: Both patients were men (aged 27 and 64 years) with incidentally detected renal masses showing infiltrative growth and discohesive large cells with a xanthomatous-eosinophilic cytoplasm, basophilic stippling, vacuolization, and prominent nucleoli. Both tumors were positive for PAX8, CD10, vimentin, and GPNMB; keratin 20 was diffusely strong in 1 patient and isolated in the other. One case showed TFE3 and Melan-A coexpression without TFE3 rearrangement. Biallelic TSC2 mutations were identified in both cases, corroborated by loss of TSC2 protein expression. Both patients were disease-free at 15 and 40 months postsurgery.

Conclusions: Xanthomatous giant cell renal cell carcinoma represents a distinct morphologic variant of TSC/MTOR-altered renal neoplasms with indolent behavior despite aggressive histologic features.

Objective: This study aimed to determine reference intervals for immunoglobulin G (IgG), IgA, IgM, and IgE concentrations in the pediatric population using an immunonephelometric method. The reliability of the derived reference intervals was assessed by comparing them with results from the Canadial Laboratory Initiative on Pediatric Reference Intervals (CALIPER) study, which employed direct methods.

Methods: A total of 120 194 IgG, IgA, IgM, and IgE results from 2020 to 2023 were extracted from the hospital database. After applying the necessary exclusion criteria, 2 groups were formed: 1 with exclusions (n = 70 565) and 1 without (n = 69 435). Immunoglobulin results were partitioned by age and sex, where required, using the Harris-Boyd method. Reference intervals were calculated using the refineR and Kolmogorov-Smirnov Distance (kosmic) indirect reference interval calculation algorithms, with and without outlier exclusion, to assess the impact of outliers.

Results: A statistically significant difference between sexes was observed only for the IgM concentrations-specifically, in the age group of 1 month to 1 year. In both groups, with and without outlier exclusion, a difference was observed only for the IgE test in the group aged 1 to 18 years, where a higher frequency of pathologic results was observed. The reference intervals calculated using the kosmic and refineR algorithms were generally consistent with each other; however, substantial differences were observed for IgA in the group aged 2 to 3 years and for the IgE test. The patterns observed in the reference intervals were consistent with those reported in the CALIPER study.

Conclusions: This study successfully verified the CALIPER pediatric reference intervals for IgG, IgA, IgM, and IgE concentrations using the immunonephelometric method.

Objective: Differentiating between the repertoire of immunoglobulin rearrangements is important in guiding diagnoses and management of B-cell lymphoma processes. A subset of these disease entities, such as chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), can show distinct genomic profiles with a shared cell of origin. In this report, we describe a rare case in which differentiating between the immunoglobulin family of rearrangements (IGH, IGK, IGL) with optical genome mapping (OGM) helped revise the clinical suspicion of CLL.

Methods: We present a 50-year-old woman with a lymphoproliferative disorder. Her clinical laboratory genetics workup included chromosomal banding analysis, fluorescence in situ hybridization, next-generation sequencing, and OGM. Optical genome mapping was performed on the bone marrow specimen, starting with the ultra-high molecular weight DNA mapped on the Saphyr system. Structural variants with OGM were detected using rare variant analysis set to default parameters.

Results: In 2021, flow cytometry performed on the peripheral blood detected a monotypic CD5+/CD23+ B-cell population. A subsequent bone marrow in 2024 detected similar findings by flow with κ light chain restriction. Chromosomal banding analysis found a translocation between the long arms of chromosomes 11 and 22. Optical genome mapping demonstrated that this translocation involved the CCND1 locus juxtaposed to the regulatory immunoglobulin λ (IGL) gene cluster.

Conclusions: We present a case of CD5+/CD10- small B-cell lymphoma that immunophenotypically resembled CLL but showed positive immunostaining for cyclin D1. The combination of the clinicopathologic findings and the CCND1 translocation involving IGL, detected by OGM, supported a revised diagnosis of MCL.

Objective: Research on CD9 expression has been extensive in B lymphoblastic leukemia, with fewer studies focusing on acute myeloid leukemia (AML). We investigated the usefulness of CD9 in differentiating normal from abnormal myeloid progenitors, as well as expression in normal cell types and in AML.

Methods: Flow cytometry was used to assess the level of CD9 expression on normal and leukemic myeloid blasts and other normal bone marrow populations. Geometric mean fluorescence intensity levels and expression patterns were compared among cell types and AML subtypes.

Results: In normal subsets (n = 69), the level of CD9 expression was lowest in mature B cells, myeloid blasts, promyelocytes, and neutrophils, with intermediate expression in monocytes and highest in hematogones (stages 1 and 2). Committed myeloid progenitors (CMPs) had lower expression than hematopoietic stem cells (HSCs). CD9 typically has higher expression in AML (n = 58) compared to normal myeloid blasts and promyelocytes, and it is differentially expressed in AML, with the highest expression in PML::RARA AML.

Conclusions: Aberrant CD9 expression can be useful differentiating normal from abnormal myeloid progenitors, with the highest level of expression in AML with PML::RARA in our cohort. There was differential expression between HSCs and CMPs in the small numbers studied. Normal mature B cells can be used as an internal negative control in most cases.