Archives of pathology & laboratory medicine最新文献

Context.—: Wilms tumor (WT) in adult patients is rare and has historically been a diagnostic and therapeutic conundrum, with limited data available in the literature.

Objective.—: To provide detailed diagnostic features, molecular profiling, and patient outcomes in a multi-institutional cohort of adult WT patients.

Design.—: We identified and retrospectively examined 4 adult WT cases.

Results.—: Two patients presented with metastatic disease, and diagnoses were made on fine-needle aspiration of their renal masses. The aspirates included malignant primitive-appearing epithelioid cells forming tubular rosettes and necrosis, and cell blocks demonstrated triphasic histology. In the remaining 2 cases, patients presented with localized disease and received a diagnosis on resection, with both patients demonstrating an epithelial-predominant morphology. Tumor cells in all cases were patchy variable positive for PAX8 and WT1 immunohistochemistry. Next-generation sequencing identified alterations previously reported in pediatric WT in 3 of 4 cases, including mutations in ASXL1 (2 of 4), WT1 (1 of 4), and the TERT promoter (1 of 4), as well as 1q gains (1 of 4); 1 case showed no alterations. Three patients were treated with pediatric chemotherapy protocols; during follow-up (range, 26-60 months), 1 patient died of disease.

Conclusions.—: WT is an unexpected and difficult entity to diagnose in adults and should be considered when faced with a primitive-appearing renal or metastatic tumor. Molecular testing may help exclude other possibilities but may not be sensitive or specific because of the relatively large number of driver mutations reported in WT.

Context.—: In 2014, the College of American Pathologists developed an evidence-based guideline to address analytic validation of immunohistochemical assays. Fourteen recommendations were offered. Per the National Academy of Medicine standards for developing trustworthy guidelines, guidelines should be updated when new evidence suggests modifications.

Objective.—: To assess evidence published since the release of the original guideline and develop updated evidence-based recommendations.

Design.—: The College of American Pathologists convened an expert panel to perform a systematic review of the literature and update the original guideline recommendations using the Grading of Recommendations Assessment, Development and Evaluation approach.

Results.—: Two strong recommendations, 1 conditional recommendation, and 12 good practice statements are offered in this updated guideline. They address analytic validation or verification of predictive and nonpredictive assays, and recommended revalidation procedures following changes in assay conditions.

Conclusions.—: While many of the original guideline statements remain similar, new recommendations address analytic validation of assays with distinct scoring systems, such as programmed death receptor-1 and analytic verification of US Food and Drug Administration approved/cleared assays; more specific guidance is offered for validating immunohistochemistry performed on cytology specimens.

Context.—: Intraoperative (frozen section) analysis of lung lesions (nodules, masses, ground-glass opacities) can occasionally be diagnostically challenging.

Objective.—: To describe selected pitfalls in thoracic frozen sections with a focus on the differential diagnosis between adenocarcinoma and its mimics, and to provide tips to prevent misinterpretation.

Data sources.—: Peer-reviewed literature and the author's experience.

Conclusions.—: A common challenge in thoracic frozen sections is the differential diagnosis between lung adenocarcinoma and its mimics. Diagnostic difficulties arise because mimics of adenocarcinoma often entrap reactive lung epithelium that can appear atypical on frozen section slides. Entities that can be misinterpreted as adenocarcinoma include ciliated muconodular papillary tumor/bronchiolar adenoma, hamartoma, inflammatory myofibroblastic tumor, and pulmonary Langerhans cell histiocytosis. Knowledge of the key clinical, radiologic, and histologic features of these entities can help prevent overdiagnosis of adenocarcinoma. Pathologic findings that facilitate the distinction between adenocarcinoma and its mimics at frozen section include the appearance and contour of the lesion at low magnification, growth patterns, cilia, stromal features, shape of the epithelial cells (cuboidal versus columnar), nuclear features of malignancy (crowding, hyperchromasia, irregular contours), and abruptness of the junction between the lesion and adjacent uninvolved lung. Knowledge of the clinical context, imaging findings, and the surgical consequence of the intraoperative diagnosis can also prevent diagnostic errors. Finally, since adenocarcinomas of the lung are often relatively bland and lack the stromal desmoplasia seen in adenocarcinomas of other organs, familiarity with the morphologic spectrum of lung adenocarcinomas at frozen section analysis is important.

Context.—: The subspecialty workforce in pathology globally is inadequate for the demands of many modern therapies. The Open Pathology Education Network (OPEN) was formed to augment the global pathology workforce. The International Gynecologic Cancer Society (IGCS) virtual gynecologic-oncology (gyn-onc) fellowship training identified needs for higher-level pathology support.

Objective.—: To report on an OPEN-IGCS pilot project to support gyn-onc and pathology education efforts in a developing country.

Design.—: Curriculum with learning objectives and content from open sources was assembled. Mentoring sessions included bidirectional case sharing. Trainees received sequential curricula assignments and had options for communication outside mentoring sessions. Pretest and posttest digital slide assessments were included. Mentors attended the gynecology tumor board, allowing for the assessment of quality and accuracy of pathology diagnosis for cases discussed.

Results.—: Learners completing the pretest and posttest showed substantial improvement, with 2 practicing pathologists improving their diagnostic scores from 60% to an average of 95%. A third trainee-level participant also improved, but to a lesser degree. Qualitative assessments included increased confidence in presentation and an increased ability to anticipate questions, raise issues of expanded differential diagnoses, and articulate appropriate workup. Observations of clinicians who participated also noted increased confidence in participating pathologists. Secondary value included establishing an expanded network of support in other subspecialties for participants. Pathologic issues at the tumor board decreased, from more than 50% in the first 3 months of study to 0% in the last 3 months of study. The curriculum was embedded into a self-paced learning portal at courses.open-pathology.org.

Conclusions.—: The OPEN-IGCS collaboration model shows the potential to provide subspecialty pathology training remotely.

Context.—: Leptomeningeal disease (LMD) is a clinical sequela of central nervous system metastasis involving the cerebrospinal fluid (CSF), often seen in late-stage solid tumors. It has a grave prognosis without urgent treatment. Standard of care methodologies to diagnose LMD include CSF cytology, magnetic resonance imaging, and clinical evaluation. These methods offer limited sensitivity and specificity for the evaluation of LMD. Here, we describe the analytic performance characteristics of a microfluidic-based tumor cell enrichment and detection assay optimized to detect epithelial cells in CSF using both contrived samples as well as CSF from patients having suspected or confirmed LMD from carcinomas.

Objective.—: To demonstrate the feasibility of using a microfluidic, multi-antibody cell capture assay to identify and quantify tumor cells in CSF.

Design.—: An artificial CSF solution was spiked with 34 different human carcinoma cell lines at different concentrations and assayed for the ability to detect tumor cells to assess analytic accuracy. Two cell lines were selected to assess linearity, intra-assay precision, interinstrument precision, and sample stability. Clinical verification was performed on 65 CSF specimens from patients. Parameters assessed included the number of tumor cells, coefficient of variation percentage, and percentage of tumor cell capture (TCC).

Results.—: Among contrived samples, average tumor cell capture ranged from 50% to 82% (261 of 522; 436 of 531), and coefficients of variation ranged from 7% to 67%. The cell capture assay demonstrated a sensitivity of 92% and a specificity of 95% among clinical samples.

Conclusions.—: This assay demonstrated the ability to detect and enumerate epithelial cells in contrived and clinical specimens in an accurate and reproducible fashion. The use of cell capture assays in CSF may be useful as a sensitive test for the diagnosis and longitudinal monitoring of LMD from solid tumors.

Context.—: Interpretation of alkaline phosphatase (ALP) activity is essential for the diagnosis of certain diseases. ALP changes during life and may vary between different populations.

Objective.—: To establish reference intervals (RIs) and percentile charts for ALP activity in the Spanish population through a multicentric observational study and to compare the RIs to those defined in other countries.

Design.—: A total of 662 350 ALP measurements from individuals ages 0 to 99 years from 9 Spanish tertiary care centers collected between 2020 and 2022 were analyzed. This study is the largest published in the literature to date.

Results.—: Continuous percentile charts for ALP according to sex and age were established which can be used as RIs. Higher levels are reached during the first weeks of life. In puberty, a differential evolution is observed in both sexes, reaching a peak at 10 to 13 years of age in boys and remaining stable in girls at this age. Significant differences were also observed in adults, higher in men between ages 20 and 49 years and between ages 50 and 79 years in women, as reported in some countries.

Conclusions.—: ALP activity follows an age- and sex-dependent fluctuation with geographic differences. It is important to have appropriate reference values for each population in order to allow for a correct diagnostic interpretation and early diagnosis of diseases related to ALP abnormalities.

Context.—: Salivary gland (SG) neoplasms (SGNs) display considerable immunophenotypic diversity. A significant proportion of SG carcinomas develop metastases with increased diagnostic difficulty at metastatic sites. Transcriptional repressor GATA binding 1 (TRPS1), a novel immunohistochemical marker for breast cancer, has been found to stain certain SGNs.

Objective.—: To investigate TRPS1 and SRY-related HMG-box 10 (SOX10) immunoexpression in various SGNs and non-SG carcinomas, head and neck paragangliomas, and head and neck mucosal melanomas.

Design.—: TRPS1 immunoreactivity score (IRS) was determined as negative or low, intermediate, or high positive; SOX10 was reported as negative or positive.

Results.—: One hundred forty-eight SGNs, 5 breast carcinomas, 105 nonbreast-non-SG carcinomas, including 33 head and neck squamous cell carcinomas (HNSCCs), 6 head and neck paragangliomas, and 6 head and neck mucosal melanomas, were assessed for TRPS1. All 23 benign SGNs showed TRPS1 positivity, with the majority having high-positive IRS (17 of 23 cases; 74%). Among 125 SG carcinomas, 115 of 125 (92%) were TRPS1 positive, with high-positive IRS in 94 of 125 (75%), intermediate positive in 15 of 125 (12%), and low positive in 6 of 125 (5%). Among nonbreast-non-SG carcinomas, HNSCC, lung, thyroid, kidney, and ovarian carcinomas showed frequent TRPS1 staining. Nearly half of HNSCCs had high (11 of 18; 33%) or intermediate (4 of 18; 12%) positive IRS. Mean IRS in SG carcinomas was significantly higher than that in nonbreast-non-SG carcinomas (P < .001). None of the TRPS1-positive nonbreast-non-SG carcinomas expressed SOX10.

Conclusions.—: TRPS1 is positive in most benign and malignant SGNs. Its expression in several nonbreast-non-SG carcinomas indicates that it lacks specificity for breast and SG carcinomas, even if considering only high-positive IRS. Addition of SOX10 can increase discriminatory utility of TRPS1.

Context.—: The National Institutes of Health Genotype-Tissue Expression (GTEx) project was developed to elucidate how genetic variation influences gene expression in multiple normal tissues procured from postmortem donors.

Objective.—: To provide critical insight into a biospecimen's suitability for subsequent analysis, each biospecimen underwent quality assessment measures that included evaluation for underlying disease and potential effects introduced by preanalytic factors.

Design.—: Electronic images of each tissue collected from nearly 1000 postmortem donors were evaluated by board-certified pathologists for the extent of autolysis, tissue purity, and the type and abundance of any extraneous tissue. Tissue-specific differences in the severity of autolysis and RNA integrity were evaluated, as were potential relationships between these markers and the duration of postmortem interval and rapidity of death.

Results.—: Tissue-specific challenges in the procurement and preservation of the nearly 30 000 tissue specimens collected during the GTEx project are summarized. Differences in the degree of autolysis and RNA integrity number were observed among the 40 tissue types evaluated, and tissue-specific susceptibilities to the duration of postmortem interval and rapidity of death were observed.

Conclusions.—: Ninety-five percent of tissues were of sufficient quality to support RNA sequencing analysis. Biospecimens, annotated whole slide images, de-identified clinical data, and genomic data generated for GTEx represent a high-quality and comprehensive resource for the scientific community that has contributed to its use in approximately 1695 articles. Biospecimens and data collected under the GTEx project are available via the GTEx portal and authorized access to the Database of Genotypes and Phenotypes; procedures and whole slide images are available from the National Cancer Institute.

Context.—: Pediatric B-cell acute lymphoblastic leukemia is genetically and phenotypically heterogeneous, with a genetic landscape including chromosomal translocations that disrupt ABL proto-oncogene 1, non-receptor tyrosine kinase (ABL1).

Objective.—: To characterize an uncommon chromosomal translocation in acute leukemia.

Design.—: Genetic testing, including karyotype and fluorescence in situ hybridization (FISH) analysis, was used to determine the underlying genetic aberration driving the disorder and to guide disease classification and risk stratification. More-detailed testing using RNA sequencing was performed, based on the results from these assays. Three-dimensional molecular modeling was used to visualize the impact of aberrant fused transcripts identified by transcriptome profiling.

Results.—: Karyotype analysis of the bone marrow demonstrated a complex karyotype with, most notably, a t(9;10)(q34.1;q22) translocation. ABL1 break-apart probe FISH findings supported ABL1 disruption. Bone marrow transcriptome analysis revealed mutant ZMIZ1::ABL1 (ZMIZ1, zinc finger MIZ-type containing 1) fusion transcripts as a consequence of t(9;10)(q34.1;q22). Three-dimensional modeling of the mutant ZMIZ1::ABL1 fusion protein confirmed an altered ABL1 protein structure compared to that of the wild type, suggesting a constitutively active conformation.

Conclusions.—: The t(9;10) translocation resulting in ZMIZ1::ABL1 fusion transcripts is an uncommon form of BCR::ABL1-like (BCR, BCR activator of RhoGEF and GTPase) acute lymphoblastic leukemia. Although the karyotype was complex, identifying the t(9;10)(q34.1;q22) translocation, ABL1 disruption, and ZMIZ1::ABL1 transcript enabled effective ABL1-targeted treatment. Our data support the use of tyrosine kinase inhibitors to treat ZMIZ1::ABL1-derived B-cell acute lymphoblastic leukemia.

Context.—: Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm that predominantly affects young children.

Objective.—: To investigate genetic alterations and their correlation with clinical characteristics and prognosis in pediatric LCH.

Design.—: We performed targeted sequencing to detect mutations in LCH lesions from pediatric patients.

Results.—: A total of 30 genomic alterations in 5 genes of the MAPK pathway were identified in 187 of 223 patients (83.9%). BRAF V600E (B-Raf proto-oncogene, serine/threonine kinase) was the most common mutation (51.6%), followed by MAP2K1 (mitogen-activated protein kinase kinase 1) alterations (17.0%) and other BRAF mutations (13.0%). ARAF (A-Raf proto-oncogene, serine/threonine kinase) and KRAS (KRAS proto-oncogene, GTPase) mutations were relatively rare (2.2% and 0.9%, respectively). Additionally, FNBP1 (formin-binding protein 1)::BRAF fusion and MAP3K10 (mitogen-activated protein kinase kinase 10) mutations A17T and R823C were identified in 1 case each, with possible constitutive activation of ERK1/2 phosphorylation. BRAF V600E was more frequent in patients with risk organ involvement, while MAP2K1 mutation was more prevalent in patients with single-system LCH (P = .001). BRAF V600E was associated with craniofacial bone, skin, liver, spleen, and ear involvement (all P < .05). Patients with other BRAF mutations had a higher proportion of spinal column involvement (P = .006). Univariate analysis showed a significant difference in progression-free survival among the 4 molecular subgroups for patients treated with first-line therapy (P = .02). According to multivariate analysis, risk organ involvement was the strongest independent adverse prognostic factor (hazard ratio, 8.854; P < .001); BRAF or MAP2K1 mutation was not an independent prognostic factor.

Conclusions.—: Most pediatric patients with LCH carry somatic mutations involving the MAPK pathway, correlating with clinical characteristics and outcomes for first-line chemotherapy.