Archives of pathology & laboratory medicine最新文献

Context.—: Detecting copy number variations (CNVs) at certain loci can aid in the diagnosis of histologically ambiguous melanocytic neoplasms. Droplet digital polymerase chain reaction (ddPCR) is a rapid, automated, and inexpensive method for CNV detection in other cancers, but not yet melanoma.

Objective.—: To evaluate the performance of a 4-gene ddPCR panel that simultaneously tests for ras responsive binding element protein 1 (RREB1) gain; cyclin-dependent kinase inhibitor 2A (CDKN2A) loss; MYC proto-oncogene, bHLH transcription factor (MYC) gain; and MYB proto-oncogene, transcription factor (MYB) loss in melanocytic neoplasms.

Design.—: One hundred sixty-four formalin-fixed, paraffin-embedded skin samples were used to develop the assay, of which 65 were used to evaluate its performance. Chromosomal microarray analysis (CMA) data were used as the gold standard.

Results.—: ddPCR demonstrated high concordance with CMA in detecting RREB1 gain (sensitivity, 86.7%; specificity, 88.9%), CDKN2A loss (sensitivity, 80%; specificity, 100%), MYC gain (sensitivity, 70%; specificity, 100%), and MYB loss (sensitivity, 71.4%; specificity, 100%). When one CNV was required to designate the test as positive, the 4-gene ddPCR panel distinguished nevi from melanomas with a sensitivity of 78.4% and a specificity of 71.4%. For reference, CMA had a sensitivity of 86.2% and a specificity of 78.6%. Our data also revealed interesting relationships with histology, namely (1) a positive correlation between RREB1 ddPCR copy number and degree of tumor progression; (2) a statistically significant correlation between MYC gain and nodular growth; and (3) a statistically significant correlation between MYB loss and a sheetlike pattern of growth.

Conclusions.—: With further validation, ddPCR may aid both in our understanding of melanomagenesis and in the diagnosis of challenging melanocytic neoplasms.

Context.—: ALK and ROS1 rearrangements are essential biomarkers to be tested in advanced lung adenocarcinomas. While D5F3 Ventana assay is a companion diagnostic for anaplastic lymphoma kinase-targeted therapy, immunohistochemistry is only a screening tool for detecting ROS1 rearrangement. Confirmation by cytogenetic or molecular techniques is necessary.

Objective.—: To evaluate the utility of ALK and ROS1 fluorescence in situ hybridization as a complement to immunohistochemistry in routine predictive biomarker testing algorithms.

Design.—: The study was ambispective, spanning 4.5 years during which lung adenocarcinoma samples were subjected to EGFR mutation testing by real-time polymerase chain reaction and ALK/ROS1 rearrangement testing by immunohistochemistry (Ventana D5F3 assay for anaplastic lymphoma kinase protein; manual assay with D4D6 clone for Ros proto-oncogene 1 protein). Fluorescence in situ hybridization was performed in all anaplastic lymphoma kinase equivocal and Ros proto-oncogene 1 immunopositive cases.

Results.—: Of 1874 samples included, EGFR mutations were detected in 27% (481 of 1796). Anaplastic lymphoma kinase immunohistochemistry was positive in 10% (174 of 1719) and equivocal in 3% (58 of 1719) of samples tested. ALK fluorescence in situ hybridization showed 81% (77 of 95) concordance with immunohistochemistry. Ros proto-oncogene 1 immunopositivity was noted in 13% (190 of 1425) of cases, with hybridization-confirmed rearrangements in 19.3% (26 of 135) of samples, all of which showed diffuse, strong- to moderate-intensity, cytoplasmic staining in tumor cells. Ros proto-oncogene 1 protein overexpression without rearrangement was significantly common in EGFR-mutant and ALK-rearranged adenocarcinomas.

Conclusions.—: Immunostaining is a robust method for ALK-rearrangement testing, with fluorescence in situ hybridization adding value in the rare equivocal stained case. ROS1-rearrangement testing is more cost-effective if immunohistochemistry is followed by fluorescence in situ hybridization after excluding EGFR-mutant and ALK-rearranged adenocarcinomas.

Context.—: The American Society of Clinical Oncology/College of American Pathologists 2018 update of the human epidermal growth factor receptor 2 (HER2) testing guideline includes a fluorescence in situ hybridization (FISH) group with a HER2 to chromosome 17 centromere (CEP17) ratio less than 2.0 and HER2 copy number 6.0 or greater (group 3), which requires integrated review of HER2 immunohistochemistry (IHC).

Objective.—: To assess the clinicopathologic features of group 3 patients and determine features associated with HER2-positive status after workup.

Design.—: Cases submitted for HER2 FISH between January 2019 and June 2022 were identified, and relevant clinicopathologic information was obtained.

Results.—: One hundred forty-two HER2 FISH cases (1.6%) were group 3. In 52 cases (36.6%) IHC was negative (0/1+), in 3 (2.8%) IHC was positive (3+), and in 86 (60.6%) IHC was 2+. Annotated IHC 2+ slides were recounted by a second reviewer in targeted areas, where 16 of 86 (18.6%) had a HER2:CEP17 ratio less than 2.0 and a HER2 copy number of 4.0 or greater to less than 6.0 (HER2 negative). After combined IHC/FISH review, 74 of 142 (52.1%) were classified as HER2 positive. HER2 copy number/cell was higher in HER2-positive compared with HER2-negative cases after the workup. The extent and intensity of staining in IHC 2+ cases did not correlate with the level of gene amplification. Twenty percent of HER2-positive patients achieved pathologic complete response.

Conclusions.—: About half of group 3 cases were classified as HER2 positive after additional workup. Pathologic complete response rates in HER2-positive cases were lower than expected for group 1 (HER2:CEP17 ratio ≥2.0; HER2 copy number ≥4.0) patients. IHC-targeted FISH recounts may be redundant and may potentially lead to classification of some patients as HER2 negative, resulting in withholding of targeted therapy.

Context.—: Spontaneous (nontraumatic) subdural hematomas have been reported yet have not been well studied.

Objective.—: To identify the neuropathologic features of acute spontaneous SDHs (ASSDHs) and their associated medical conditions.

Design.—: A retrospective study of 235 autopsy cases of SDH was conducted. Review of demographics, underlying medical conditions, and coagulation profile as well as gross and histopathologic examination of the brain and other organs were performed.

Results.—: Among the 32 cases of ASSDH, 5 cases (15.6%) had severe hemorrhage and 4 (12.5%) demonstrated brain herniation. Twenty-two cases (68.8%) had concurrent but nonconnecting subarachnoid hemorrhage or intraparenchymal hemorrhage. The most common underlying medical condition was thrombocytopenia (n = 21; 65.6%), followed by immunosuppression (n = 15; 46.9), bloodstream infections or sepsis (n = 12; 37.5%), hypertension (n = 13; 40.6%), and coronary artery disease (n = 12; 37.5%). Many patients with thrombocytopenia or immunosuppression had underlying malignancies, with leukemia being the most common type (n = 11; 34.4%). The use of circulatory devices or hemodialysis was noted in a significant portion of ASSDH cases. In terms of coagulation factors, most of our ASSDH patients had normal prothrombin time and activated partial thromboplastin time, but abnormal platelet count and D-dimer levels.

Conclusions.—: ASSDHs can be severe and are often associated with subarachnoid hemorrhage and/or intraparenchymal hemorrhage. The causes of ASSDH are limited to certain underlying medical conditions that ultimately lead to bleeding tendency. Autopsies are helpful in determining the etiology. Given their association with abnormal platelet count, correcting platelet deficiencies is a potential preventive measure for ASSDHs.

Context.—: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) assay reagents are available both with and without supplementation with pyridoxal-5'-phosphate (P5P; the active form of vitamin B6), a catalytic cofactor required for their enzymatic reactions. Nonsupplemented assays may miss ALT or AST elevations in patients with vitamin B6 deficiency.

Objective.—: To assess awareness and adoption of ALT and AST reagents that are supplemented with P5P.

Design.—: A 4-question survey about ALT and AST reagent supplementation with P5P was included in the College of American Pathologists General Chemistry and Therapeutic Drugs (C program) proficiency testing 2023 B mailing.

Results.—: Overall, 38% (1651 of 4304) of responding laboratories reported using ALT and/or AST reagent supplemented with P5P. P5P supplementation was more common for nonacademic hospital/medical center laboratories (44%; 713 of 1629) relative to other settings. Of the laboratories that reported not using P5P-supplemented reagents, few (5%; 141 of 2611) cited plans to convert in the future. Despite the availability of P5P-supplemented reagents from several major assay manufacturers, the most common stated barrier for adoption was that the laboratory's reagent manufacturer does not provide P5P-supplemented reagents.

Conclusions.—: There is a lack of awareness of the existence and benefits of P5P-supplemented ALT and AST reagents. There is a need for ALT and AST assay manufacturers to clarify and standardize the P5P status of ALT and AST reagents.

Context.—: Therapeutic drug monitoring is recommended to optimize infliximab use and improve outcome in chronic inflammatory disorders.

Objective.—: To describe a simple and affordable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to measure infliximab in serum.

Design.—: Infliximab was measured using winged stable isotope-labeled peptides as internal standards. Linearity, lower limit of measuring interval, limit of detection, precision, accuracy, carryover, and ion suppression were evaluated. Method comparison against 2 enzyme-linked immunosorbent assay (ELISA) methods (Remsima Monitor and IDKmonitor Infliximab) and anti-drug antibody (ADA) interference were evaluated using clinical specimens from inflammatory bowel disease patients (N = 237).

Results.—: Analytical run time and sample preparation time were 5 minutes per sample and 3 hours per batch, respectively. Analytical measurement interval and limit of detection were 0.50 to 50.0 μg/mL (R2 = 0.998) and 0.25 μg/mL, respectively. The intraday and interday imprecision percentage coefficients of variation were less than 6.1%. Accuracy was 94.2% to 98.7%. No significant ion suppression or carryover was observed. Infliximab concentrations measured by LC-MS/MS showed good agreement with those measured by Remsima Monitor (mean percentage difference, 5.7%; 95% CI, -1.2% to 12.6%) but were markedly lower than those measured by IDKmonitor (-32.6%; -35.8% to -29.4%), demonstrating significant bias between ELISAs. Although a good agreement between LC-MS/MS and ELISA was observed for ADA-negative samples (-3.5%; -12.8% to 5.9%), a significant bias was observed for ADA-positive samples (13.6%; 1.7% to 25.6%).

Conclusions.—: This simple, fast, and affordable LC-MS/MS method for infliximab quantitation could improve standardization of infliximab quantitation and optimization of infliximab use in patients with high-titer ADA.

Context.—: Mammographic identification of microcalcifications may result in biopsy because many calcifications serve as markers for breast pathology. Absence of these calcifications in histologic sections may indicate that an area of concern has not been adequately sampled.

Objective.—: To determine the optimal cutting protocols to identify mammary calcifications.

Design.—: Our standard protocol for breast biopsies with suspected mircocalcifications is to cut 2 levels separated by 30 µm and if no microcalcifications are detected, an additional 10 levels are obtained. An electronic search of surgical pathology records was performed for cases with microcalcifications identified between January 1, 2022, and March 30, 2023. For each case, slides designated by the radiologist as containing microcalcifications were retrieved. The level at which microcalcifications were first detected was recorded.

Results.—: The search revealed 431 specimens meeting the search criteria, of which 415 contained microcalcifications. Probability of finding microcalcifications in the initial level was 0.629 and the probability of detecting microcalcifications in the first 4 levels was 0.905. Four hundred three of 415 microcalcifications documented by mammographic imaging (97%) were detected histologically in the first 6 levels.

Conclusions.—: A 6-level approach appears optimal for the detection of microcalcifications. This study may have implications for other specimen types where a strong suspicion exists for a pathologic lesion, but examination reveals no lesions in the initial sections. Protocols using 6-level-deep cuts may represent optimal sampling.

Context.—: Manifestations of immunoglobulin G4-related disease (IgG4-RD) occur in several organ systems and anatomic locations, including the nasal cavity and paranasal sinuses. Other processes affecting the sinonasal tract, such as chronic rhinosinusitis, aspirin-exacerbated respiratory disease, and nasal polyposis, also involve IgG4.

Objective.—: To characterize an association between IgG4 and nasal lesions arising in the clinical context of intranasal drug use.

Design.—: The cases of 3 patients (2 with histories of intranasal cocaine abuse, and 1 with intranasal heroin abuse) were evaluated. Clinical features of each case were compiled from the electronic medical record. Histologic morphology of surgical specimens was examined. Immunohistochemical staining was performed to assess involvement of/association with IgG4.

Results.—: Clinical features of these lesions included diffuse necrotic fibrinous debris, scarring, and endoscopically evident inflammation. Tissue sections showed acutely and chronically inflamed respiratory-type mucosa with abundant IgG4-positive plasma cells. Although these cases share some aspects in common with IgG4-RD, other definitive characteristics are absent, and notable differences exist.

Conclusions.—: This series provides the first demonstration of increased IgG4 expression in nasal lesions associated with intranasal drug use. Despite some similarities, the pathologic processes and IgG4-rich infiltrates in these 3 cases seem to represent a different phenomenon that is not IgG4-RD. Although these lesions contain abundant IgG4-positive cells, they should not be mistaken for or conflated with IgG4-RD.