Effect of decalcification protocols on immunohistochemistry and molecular analyses of bone samples

Best practices for achieving consensus in HER2-low expression in breast cancer: current perspectives from practising pathologists

AIMS

Human epidermal growth factor receptor 2 (HER2) expression is an important biomarker in breast cancer (BC). Most BC cases categorised as HER2-negative (HER2-) express low levels of HER2 [immunohistochemistry (IHC) 1+ or IHC 2+/in-situ hybridisation not amplified (ISH-)] and represent a clinically relevant therapeutic category that is amenable to targeted therapy using a recently approved HER2-directed antibody-drug conjugate. A group of practising pathologists, with expertise in breast pathology and BC biomarker testing, outline best practices and guidance for achieving consensus in HER2 IHC scoring for BC.

METHODS AND RESULTS

The authors describe current knowledge and challenges of IHC testing and scoring of HER2-low expressing BC and provide best practices and guidance for accurate identification of BCs expressing low levels of HER2. These expert pathologists propose an algorithm for assessing HER2 expression with validated IHC assays and incorporate the 2023 American Society of Clinical Oncology and College of American Pathologist guideline update. The authors also provide guidance on when to seek consensus for HER2 IHC scoring, how to incorporate HER2-low into IHC reporting and present examples of HER2 IHC staining, including challenging cases.

CONCLUSIONS

Awareness of BC cases that are negative for HER protein overexpression/gene amplification and the related clinical relevance for targeted therapy highlight the importance of accurate HER2 IHC scoring for optimal treatment selection.

Precision Medicine in Cytopathology

Over the last decade, cancer diagnostics has undergone a notable transformation with increasing complexity. Minimally invasive diagnostic tests, driven by advanced imaging and early detection protocols, are redefining patient care and reducing the need for more invasive procedures. Modern cytopathologists now safeguard patient samples for vital biomarker and molecular testing. In this article, we explore ancillary testing modalities and the role of biomarkers in organ-specific contexts, underscoring the transformative impact of precision medicine. Finally, the advent of more than 80 Food and Drug Administration-approved predictive biomarkers signals a new era, guiding cancer care toward personalized and targeted strategies.

In situ metabolomic analysis of osteonecrosis of the femoral head (ONFH) using MALDI MSI

Osteonecrosis of the femoral head (ONFH) is a common orthopedic disease characterized by disability and deformity. To better understand ONFH at molecular level and to explore the possibility of early diagnosis, instead of diagnosis based on macroscopic spatial characteristics, a matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) method was developed for ONFH disease for the first time. The most challenging step for ONFH MSI is to deal with human bone tissues which are much harder than the other biological samples studied by the reported MSI studies. In this work, the MSI sectioning method of hard bone tissues was established using tender acids and a series of test criteria. Small-molecule metabolites, such as lipids and amino acids, were detected in bone sections, realizing the in situ detection of spatial distribution of biometabolites. By comparing the distribution of metabolites from different regions of normal femoral head, ONFH bone tissue (ONBT), and adjacent ONFH bone tissue (ANBT), the whole process of femoral head from normal stage to necrosis was monitored and visualized at molecular level. Moreover, this developed MSI method was used for metabolomics study of ONFH. 72 differential metabolites were identified, suggesting that disturbances in energy metabolism and lipid metabolism affected the normal life activities of osteoblasts and osteoclasts. This study provides new perspectives for future pathological studies of ONFH.

High-Specificity Imaging Mass Spectrometry

Imaging mass spectrometry (IMS) enables highly multiplexed, untargeted tissue mapping for a broad range of molecular classes, facilitating in situ biological discovery. Yet, challenges persist in molecular specificity, which is the ability to discern one molecule from another, and spatial specificity, which is the ability to link untargeted imaging data to specific tissue features. Instrumental developments have dramatically improved IMS spatial resolution, allowing molecular observations to be more readily associated with distinct tissue features across spatial scales, ranging from larger anatomical regions to single cells. High-performance mass analyzers and systems integrating ion mobility technologies are also becoming more prevalent, further improving molecular coverage and the ability to discern chemical identity. This review provides an overview of recent advancements in high-specificity IMS that are providing critical biological context to untargeted molecular imaging, enabling integrated analyses, and addressing advanced biomedical research applications.

Effects of fixation and demineralization on histomorphology and DNA amplification of canine bone marrow

Fixation and demineralization protocols for bone marrow (BM) across diagnostic laboratories are not standardized. How different protocols affect histomorphology and DNA amplification is incompletely understood. In this study, 2 fixatives and 3 demineralization methods were tested on canine BM samples. Twenty replicate sternal samples obtained within 24 hours of death were fixed overnight in either acetic acid-zinc-formalin (AZF) or 10% neutral-buffered formalin (NBF) and demineralized with formic acid for 12 hours. Another 53 samples were fixed in AZF and demineralized with hydrochloric acid for 1-hour, formic acid for 12 hours, or ethylenediamine tetraacetic acid (EDTA) for 24 hours. Histologic sections were scored by 4 raters as of insufficient, marginal, good, or excellent quality. In addition, DNA samples extracted from sections treated with the different fixation and demineralization methods were amplified with 3 sets of primers to conserved regions of T cell receptor gamma and immunoglobulin heavy chain genes. Amplification efficiency was graded based on review of capillary electrophoretograms. There was no significant difference in the histomorphology scores of sections fixed in AZF or NBF. However, EDTA-based demineralization yielded higher histomorphology scores than demineralization with hydrochloric or formic acid, whereas formic acid resulted in higher scores than hydrochloric acid. Demineralization with EDTA yielded DNA amplification in 29 of 36 (81%) samples, whereas demineralization with either acid yielded amplification in only 2 of 72 (3%) samples. Although slightly more time-consuming and labor-intensive, tissue demineralization with EDTA results in superior morphology and is critical for polymerase chain reaction (PCR) amplification with the DNA extraction method described in this article.

Unveiling novel insights in acute myeloid leukemia through single-cell RNA sequencing

Acute myeloid leukemia (AML) is a complex and heterogeneous group of aggressive hematopoietic stem cell disease. The presence of diverse and functionally distinct populations of leukemia cells within the same patient's bone marrow or blood poses a significant challenge in diagnosing and treating AML. A substantial proportion of AML patients demonstrate resistance to induction chemotherapy and a grim prognosis upon relapse. The rapid advance in next generation sequencing technologies, such as single-cell RNA-sequencing (scRNA-seq), has revolutionized our understanding of AML pathogenesis by enabling high-resolution interrogation of the cellular heterogeneity in the AML ecosystem, and their transcriptional signatures at a single-cell level. New studies have successfully characterized the inextricably intertwined interactions among AML cells, immune cells and bone marrow microenvironment and their contributions to the AML development, therapeutic resistance and relapse. These findings have deepened and broadened our understanding the complexity and heterogeneity of AML, which are difficult to detect with bulk RNA-seq. This review encapsulates the burgeoning body of knowledge generated through scRNA-seq, providing the novel insights and discoveries it has unveiled in AML biology. Furthermore, we discuss the potential implications of scRNA-seq in therapeutic opportunities, focusing on immunotherapy. Finally, we highlight the current limitations and future direction of scRNA-seq in the field.

Current and emerging sequencing-based tools for precision cancer medicine

Current precision cancer medicine is dependent on the analyses of a plethora of clinically relevant genomic aberrations. During the last decade, next-generation sequencing (NGS) has gradually replaced most other methods for precision cancer diagnostics, spanning from targeted tumor-informed assays and gene panel sequencing to global whole-genome and whole-transcriptome sequencing analyses. The shift has been impelled by a clinical need to assess an increasing number of genomic alterations with diagnostic, prognostic and predictive impact, including more complex biomarkers (e.g. microsatellite instability, MSI, and homologous recombination deficiency, HRD), driven by the parallel development of novel targeted therapies and enabled by the rapid reduction in sequencing costs. This review focuses on these sequencing-based methods, puts their emergence in a historic perspective, highlights their clinical utility in diagnostics and decision-making in pediatric and adult cancer, as well as raises challenges for their clinical implementation. Finally, the importance of applying sensitive tools for longitudinal monitoring of treatment response and detection of measurable residual disease, as well as future avenues in the rapidly evolving field of sequencing-based methods are discussed.

Clinicopathological analysis of thyroid carcinomas with the RET and NTRK fusion genes: characterization for genetic analysis

Thyroid carcinomas exhibit various genetic alterations, including the RET and NTRK fusion genes that are targets for molecular therapies. Thus, detecting fusion genes is crucial for devising effective treatment plans. This study characterized the pathological findings associated with these genes to identify the specimens suitable for genetic analysis. Thyroid carcinoma cases positive for the fusion genes were analyzed using the Oncomine Dx Target Test. Clinicopathological data were collected and assessed. Among the 74 patients tested, 8 had RET and 1 had NTRK3 fusion gene. Specifically, of the RET fusion gene cases, 6 exhibited "BRAF-like" atypia and 2 showed "RAS-like" atypia, while the single case with an NTRK3 fusion gene presented "RAS-like" atypia. Apart from one poorly differentiated thyroid carcinoma, most cases involved papillary thyroid carcinomas (PTCs). Primary tumors showed varied structural patterns and exhibited a high proportion of non-papillary structures. Dysmorphic clear cells were frequently observed. BRAF V600E immunoreactivity was negative in all cases. Interestingly, some cases exhibited similarities to diffuse sclerosing variant of PTC characteristics. While calcification in lymph node metastases was mild, primary tumors typically required hydrochloric acid-based decalcification for tissue preparation. This study highlights the benefits of combining morphological and immunohistochemical analyses for gene detection and posits that lymph node metastases are more suitable for genetic analysis owing to their mild calcification. Our results emphasize the importance of accurate sample processing in diagnosing and treating thyroid carcinomas.

Diagnostics of IDH1/2 Mutations in Intracranial Chondroid Tumors: Comparison of Molecular Genetic Methods and Immunohistochemistry

Intracranial chondroid tumors are a heterogeneous group of neoplasms characterized by the presence of a cartilage matrix. These tumors exhibit overlapping clinical and histological features. Mutations in IDH1/2 genes serve as important diagnostic markers of tumor type, particularly chondrosarcoma. To improve the accuracy of IDH1/2 diagnostics, we compared three methods: biochip assay, real-time PCR with DNA melting analysis using TaqMan probes and sequencing (qPCR-DMA-Sanger), and immunohistochemistry (IHC). Tumor samples from 96 patients were investigated. The IDH1 mutations were detected in 34/64 (53%) chondrosarcomas; IHC detected 27/56 (48.2%) mutations, the qPCR-DMA-Sanger method 27/59 (46%) mutations, and the biochip assay revealed 29/60 (48.3%) mutations. The detection of IDH1 mutations in chordoma (2/15) and osteosarcoma (2/7) suggested the need for a revised diagnosis. In benign tumors, IDH1 mutations were present in chondroma (4/6), but absent in chondromyxoid fibroma (0/4). The most frequent IDH1 mutations were R132C (60%), R132L, and R132G (13.5% each), R132H (8%), and R132S (5%). The concordance between the biochip assay and IHC was 90%, between IHC and PCR-DMA-Sanger 83%, and between biochip assay and qPCR-DMA-Sanger was 98%, respectively. No IDH2 mutations were found. The use of independent diagnostic methods may improve the detection of IDH-mutant specimens in chondroid tumors.

Direct specimen collection during routine operation improves nucleic acid quality in genetic analysis samples for head and neck tumors: A retrospective study

The nucleic acid integrity of head and neck squamous cell carcinoma (HNSCC) samples is poor, and the material available for genetic analysis is limited. Therefore, to expand the effectiveness of personalized medicine in patients with HNSCC, a new sampling method is needed. In total, 128 samples from 44 patients with HNSCC were studied: 32 genetic analysis samples (GASs) collected as 5 × 5 × 5 mm tissue fragments from resected large tumors and immediately embedded in a small formalin bottle within 10 min (i.e., the ischemic time), 43 primary tumor components (primary), 14 decalcified tumor (DC) samples, 32 metastatic tumors in lymph nodes (LNs), and 7 parakeratinized components (PKCs). The nucleic acid quality in the GAS, primary, DC, LN, and PKC groups was compared and next-generation sequencing (NGS) was performed. DNA integrity number and percentage of RNA fragments with > 200 nucleotides were significantly higher in the GAS group than those in the other groups. RNA integrity number decreased first in LN, followed by GAS, primary, and DC. No significant differences were observed in DIN, RIN and DV200 among the PKC, primary and LN. Following methyl green-pyronin staining, preserved DNA and RNA were not visualized in DC samples. Most NGS metrics did not differ significantly among primary, LN, and PKC samples. In conclusion, GASs should be collected during routine hospital activities. When the volume of viable materials is limited, PKCs should be considered for genetic analysis.

Development and Validation of a New BAG-1L-Specific Antibody to Quantify BAG-1L Protein Expression in Advanced Prostate Cancer

BCL-2-associated athanogene-1L (BAG-1L) is a critical co-regulator that binds to and enhances the transactivation function of the androgen receptor, leading to prostate cancer development and progression. Studies investigating the clinical importance of BAG-1L protein expression in advanced prostate cancer have been limited by the paucity of antibodies that specifically recognize the long isoform. In this study, we developed and validated a new BAG-1L-specific antibody using multiple orthogonal methods across several cell lines with and without genomic manipulation of BAG-1L and all BAG-1 isoforms. Following this, we performed exploratory immunohistochemistry to determine BAG-1L protein expression in normal human, matched castration-sensitive prostate cancer (CSPC) and castration-resistant prostate cancer (CRPC), unmatched primary and metastatic CRPC, and early breast cancer tissues. We demonstrated higher BAG-1L protein expression in CRPC metastases than in unmatched, untreated, castration-sensitive prostatectomies from men who remained recurrence-free for 5 years. In contrast, BAG-1L protein expression did not change between matched, same patient, CSPC and CRPC biopsies, suggesting that BAG-1L protein expression may be associated with more aggressive biology and the development of castration resistance. Finally, in a cohort of patients who universally developed CRPC, there was no association between BAG-1L protein expression at diagnosis and time to CRPC or overall survival, and no association between BAG-1L protein expression at CRPC biopsy and clinical outcome from androgen receptor targeting therapies or docetaxel chemotherapy. The limitations of this study include the requirement to validate the reproducibility of the assay developed, the potential influence of pre-analytical factors, timing of CRPC biopsies, relatively small patient numbers, and heterogenous therapies on BAG-1L protein expression, and the clinical outcome analyses performed. We describe a new BAG-1L-specific antibody that the research community can further develop to elucidate the biological and clinical significance of BAG-1L protein expression in malignant and nonmalignant diseases.

Effects of glycation end-products on the dental pulp in patients with type 2 diabetes

AIM

This ex vivo study aimed to compare protein expression of advanced glycation end-products (AGE) and receptor (RAGE), and the levels of selected genes associated with inflammation and collagen within dental pulp tissue from patients with type 2 (T2D) diabetes and non-T2D.

METHODOLOGY

Noncarious extracted permanent molar teeth from patients with well-controlled T2D (n = 19) and non-T2D (controls) (n = 19) were collected and compared. The coronal pulp was examined using immunohistochemistry (IHC) (n = 10 per group) for anti-AGE and anti-RAGE. Quantitative PCR (n = 9 per group) was used to analyse the gene expression levels of NFKB, S100A12 and COLIA1. Data analyses were performed between the groups using GraphPad Prism using Pearson correlation, Shapiro-Wilk and Mann-Whitney U-tests, and multiple regression using SPSS.

RESULTS

AGEs were distributed diffusely throughout the pulp extracellular matrix associated with collagen fibres and were present on several cell types. RAGE was expressed at the pulp-dentine interface and was observed on odontoblasts, immune cells, endothelial cells and fibroblasts. Semi-quantitative analysis of IHC samples showed significantly increased expression of AGE (p < .0001) and RAGE (p = .02) in T2D samples compared with controls. The expression of NFKB (p < .0001), S100A12 (p < .0001) and COLIA1 (p = .01) genes were significantly higher in the T2D pulp, and multivariate logistic regression analysis showed that these findings were not affected by age.

CONCLUSION

T2D may exert a similar glycation response in the dental pulp to other body sites. This could occur through activation of NF-κB pathways with a concomitant increase in genes associated with inflammation and collagen.

TRPS1, a New Promising Marker for Assessment of Distant Metastatic Breast Cancer

This article reviewed the identification of breast cancer in the distant metastatic setting through traditional immunohistochemical markers, such as mammaglobin and GATA3, compared with the novel immunohistochemical stain, Trichorhinophalangeal syndrome-1 (TRPS1). We review previous studies evaluating TRPS1 staining, which were conducted using cytology specimens, as well as our recently conducted study evaluating this stain using surgical tissue samples, both from primary and distant metastatic invasive breast carcinoma. In summary, although no immunohistochemical stain is 100% specific or sensitive, in the metastatic setting where tissue available for ancillary studies is limited, TRPS1 was a reliable and even a standalone marker for breast origin, particularly in cases of triple-negative breast cancer.

Formalin-Fixed, Paraffin-Embedded-Targeted Locus Capture: A Next-Generation Sequencing Technology for Accurate DNA-Based Gene Fusion Detection in Bone and Soft Tissue Tumors

Chromosomal rearrangements are important drivers in cancer, and their robust detection is essential for diagnosis, prognosis, and treatment selection, particularly for bone and soft tissue tumors. Current diagnostic methods are hindered by limitations, including difficulties with multiplexing targets and poor quality of RNA. A novel targeted DNA-based next-generation sequencing method, formalin-fixed, paraffin-embedded-targeted locus capture (FFPE-TLC), has shown advantages over current diagnostic methods when applied on FFPE lymphomas, including the ability to detect novel rearrangements. We evaluated the utility of FFPE-TLC in bone and soft tissue tumor diagnostics. FFPE-TLC sequencing was successfully applied on noncalcified and decalcified FFPE samples (n = 44) and control samples (n = 19). In total, 58 rearrangements were identified in 40 FFPE tumor samples, including three previously negative samples, and none was identified in the FFPE control samples. In all five discordant cases, FFPE-TLC could identify gene fusions where other methods had failed due to either detection limits or poor sample quality. FFPE-TLC achieved a high specificity and sensitivity (no false positives and negatives). These results indicate that FFPE-TLC is applicable in cancer diagnostics to simultaneously analyze many genes for their involvement in gene fusions. Similar to the observation in lymphomas, FFPE-TLC is a good DNA-based alternative to the conventional methods for detection of rearrangements in bone and soft tissue tumors.

Lactobacillus acidophilus supernatant alleviates osteoporosis by upregulating colonic SERT expression

Aims: To investigate the involvement of serotonin transporter (SERT) in colonic epithelial cells in the anti-osteoporosis role of Lactobacillus acidophilus (LA) supernatant (LAS). Methods: The abundance of fecal LA and bone mineral density (BMD) in patients with osteoporosis (OP) or severe osteoporosis were assessed. The protective role of LA in osteoporosis and the expression of SERT and relative signaling were evaluated. Results: Abundance of fecal LA was decreased in patients with severe OP and was positively correlated with BMD. Supplementing LAS to mice alleviated senile osteoporosis. In vitro, NOD2/RIP2/NF-κB signaling was inhibited by LAS due to increased SERT expression. Conclusion: LAS alleviates OP in mice by producing protective metabolites and upregulating SERT expression and represents a promising therapeutic agent.

Diagnostic value of MDM2 RNA in situ hybridization for low-grade osteosarcoma: Consistency comparison of RNA in situ hybridization, fluorescence in situ hybridization, and immunohistochemistry

Detection of MDM2 gene amplification via fluorescence in situ hybridization (FISH) and MDM2 overexpression by immunohistochemistry (IHC) have been utilized for the diagnosis of low-grade osteosarcoma (LGOS). The aim of this study was to evaluate the diagnostic value of MDM2 RNA in situ hybridization (RNA-ISH) and compare this assay with MDM2 FISH and IHC in distinguishing LGOS from its histologic mimics. MDM2 RNA-ISH, FISH and IHC were performed on nondecalcified samples of 23 LGOSs and 52 control cases. Twenty (20/21, 95.2%) LGOSs were MDM2-amplified, and two cases failed in FISH. All control cases were MDM2-nonamplified. All 20 MDM2-amplified LGOSs and one MDM2-nonamplified LGOS harboring TP53 mutation and RB1 deletion showed positivity for RNA-ISH. Fifty of the 52 (96.2%) control cases were negative for RNA-ISH. The diagnostic sensitivity and specificity of MDM2 RNA-ISH were 100.0% and 96.2%, respectively. Nineteen of the 23 LGOSs were evaluated by MDM2 RNA-ISH and FISH in decalcified samples simultaneously. All decalcified LGOSs failed in FISH and most samples (18/19) were no staining in RNA-ISH. Fifteen (15/20, 75%) MDM2-amplified LGOSs were positive for IHC and 96.2% (50/52) of control cases were negative. The sensitivity of RNA-ISH (100%) was higher than that of IHC (75%). In conclusion, MDM2 RNA-ISH has great value for the diagnosis of LGOS, with excellent consistency with FISH and better sensitivity than IHC. Acid decalcification still has an adverse impact on RNA. Some MDM2-nonamplified tumors may show positivity for MDM2 RNA-ISH, which needs to be analyzed comprehensively in combination with clinicopathological features.

Arduino Automated Microwave Oven for Tissue Decalcification

Decalcification of hard tissues such as bone and teeth is a complex process that requires using chemicals such as acids and chelating agents. Acids act faster than chelating agents, but they have a greater risk of damaging biological samples. Increasing the reaction speed of the chelating agent may solve this issue. There are several strategies to speed up this process, and using microwaves seems to be one of the most effective. However, lab-dedicated microwave ovens are expensive, and their purchase may seem unjustified. Therefore, a low-cost modification of a commercial microwave oven, consisting of an Arduino automation device, has been developed. The setup has proven reliable for continuous work, thanks to implementing an electronic safety circuit. In addition, it may reduce the decalcification time using a chelating agent, achieving optimal results regarding tissue preservation and quality of histological sections.

Brazilian Expert Consensus for NTRK Gene Fusion Testing in Solid Tumors

Oncogenic neurotrophic tropomyosin receptor kinase gene fusions occur in less than 1% of common cancers. These mutations have emerged as new biomarkers in cancer genomic profiling with the approval of selective drugs against tropomyosin receptor kinase fusion proteins. Nevertheless, the optimal pathways and diagnostic platforms for this biomarker's screening and genomic profiling have not been defined and remain a subject of debate. A panel of national experts in molecular cancer diagnosis and treatment was convened by videoconference and suggested topics to be addressed in the literature review. The authors proposed a testing algorithm for oncogenic neurotrophic tropomyosin receptor kinase gene fusion screening and diagnosis for the Brazilian health system. This review aims to discuss the latest literature evidence and international consensus on neurotrophic tropomyosin receptor kinase gene fusion diagnosis to devise clinical guidelines for testing this biomarker. We propose an algorithm in which testing for this biomarker should be requested to diagnose advanced metastatic tumors without known driver mutations. In this strategy, Immunohistochemistry should be used as a screening test followed by confirmatory next-generation sequencing in immunohistochemistry-positive cases.

Comprehensive molecular profiling of sarcomas in adolescent and young adult patients: Results of the EORTC SPECTA-AYA international proof-of-concept study

BACKGROUND

Adolescent and young adult (AYA) patients with cancer are poorly recruited to molecularly targeted trials and have not witnessed the advances in cancer treatment and survival seen in other age groups. We report here a pan-European proof-of-concept study to identify actionable alterations in some of the worst prognosis AYA cancers: bone and soft tissue sarcomas.

DESIGN

Patients aged 12-29 years with newly diagnosed or recurrent, intermediate or high-grade bone and soft tissue sarcomas were recruited from six European countries. Pathological diagnoses were centrally reviewed. Formalin-fixed tissues were analysed by whole exome sequencing, methylation profiling and RNA sequencing and were discussed in a multidisciplinary, international molecular tumour board.

RESULTS

Of 71 patients recruited, 48 (median 20 years, range 12-28) met eligibility criteria. Central pathological review confirmed, modified and re-classified the diagnosis in 41, 3, and 4 cases, respectively. Median turnaround time to discussion at molecular tumour board was 8.4 weeks. whole exome sequencing (n = 48), methylation profiling (n = 44, 85%) and RNA sequencing (n = 24, 50%) led to therapeutic recommendations for 81% patients, including 4 with germ line alterations. The most common were for agents targeted towards tyrosine kinases (n = 20 recommendations), DNA repair (n = 18) and the PI3K/mTOR/AKT pathway (n = 15). Recommendations were generally based on weak evidence such as activity in a different tumour type (n = 68, 61%), reflecting the dearth of relevant molecular clinical trial data in the same tumour type.

CONCLUSIONS

We demonstrate here that comprehensive molecular profiling of AYA patients' samples is feasible and deliverable in a European programme.

Comparison of Different Fixation Methods for Combined Histological and Biomolecular Analysis of Fixed and Decalcified Bone Samples

The combination of histological and biomolecular analyses provides deep understanding of different biological processes and is of high interest for basic and applied research. However, the available analytical methods are still limited, especially when considering bone samples. This study compared different fixation media to identify a sufficient analytical method for the combination of histological, immuno-histological and biomolecular analyses of the same fixed, processed and paraffin embedded bone sample. Bone core biopsies of rats’ femurs were fixed in different media (RNAlater + formaldehyde (R + FFPE), methacarn (MFPE) or formaldehyde (FFPE)) for 1 week prior to decalcification by EDTA and further histological processing and paraffin embedding. Snap freezing (unfixed frozen tissue, UFT) and incubation in RNAlater were used as additional controls. After gaining the paraffin sections for histological and immunohistological analysis, the samples were deparaffined and RNA was isolated by a modified TRIZOL protocol. Subsequently, gene expression was evaluated using RT-qPCR. Comparable histo-morphological and immuno-histological results were evident in all paraffin embedded samples of MFPE, FFPE and R + FFPE. The isolated RNA in the group of MFPE showed a high concentration and high purity, which was comparable to the UFT and RNAlater groups. However, in the groups of FFPE and R + FFPE, the RNA quality and quantity were statistically significantly lower when compared to MFPE, UFT and RNAlater. RT-qPCR results showed a comparable outcome in the group of MFPE and UFT, whereas the groups of FFPE and R + FFPE did not result in a correctly amplified gene product. Sample fixation by means of methacarn is of high interest for clinical samples to allow a combination of histological, immunohistological and biomolecular analysis. The implementation of such evaluation method in clinical research may allow a deeper understanding of the processes of bone formation and regeneration.

Evaluation of EDTA and nitric acid solutions for decalcification of joints in AG/WT, BALB/c, C57, DBA1/J mice, and in Wistar rats

Decalcification of mineralized samples for microscopic analysis involves competing factors including decalcification time, preservation of tissue integrity and cost. We investigated the utility of different decalcification solutions for studying joints in AG/WT, BALB/c, C57, DBA1/J mice and Wistar rats. The hind paws of the rodents were removed and fixed with 10% buffered formalin. Specimens were divided randomly into three groups for demineralization: 10% nitric acid, 12.5% EDTA at room temperature and 12.5% EDTA at 35 °C with shaking. Sections of joints were stained with hematoxylin and eosin (H & E). We evaluated decalcification time and expense, ease of cutting sections, preservation of nuclear basophilia and intranuclear detail, and intensity of eosin staining. The 10% nitric acid solution produced the most rapid decalcification for the mice, but not the rats. The 12.5% EDTA solution at 35 °C with shaking did not decrease decalcification time. Effects on microtomy were variable as were the effects on H & E staining. The EDTA solution provided the best basophilia and intranuclear detail for the mice. For rats, only 12.5% EDTA at 35 °C with shaking produced good preservation. Preservation of nuclear basophilia and intranuclear detail for rats was best with 10% nitric acid and EDTA 35 °C. For mice, 10% nitric acid failed to preserve nuclear basophilia and intranuclear detail. For intensity of eosin staining, EDTA at room temperature and EDTA 35 °C was best for both mice and rats. Sections also exhibited good H & E staining in most samples decalcified with 10% nitric acid. Although we found considerable variation among groups of animals, we found less variation among the different mouse strains than between mice and Wistar rats.

FFPE-Based NGS Approaches into Clinical Practice: The Limits of Glory from a Pathologist Viewpoint

The introduction of next-generation sequencing (NGS) in the molecular diagnostic armamentarium is deeply changing pathology practice and laboratory frameworks. NGS allows for the comprehensive molecular characterization of neoplasms, in order to provide the best treatment to oncologic patients. On the other hand, NGS raises technical issues and poses several challenges in terms of education, infrastructures and costs. The aim of this review is to give an overview of the main NGS sequencing platforms that can be used in current molecular diagnostics and gain insights into the clinical applications of NGS in precision oncology. Hence, we also focus on the preanalytical, analytical and interpretative issues raised by the incorporation of NGS in routine pathology diagnostics.

The use of alkaline phosphatase and runx2 to distinguish osteosarcoma from other common malignant primary bone tumors in dogs

In dogs, primary bone tumors can be difficult to distinguish with histopathology. Of those tumors, osteosarcoma (OSA) is the most common and aggressive. In this study, 4 immunohistochemistry markers-alkaline phosphatase (ALP), osteonectin (ON), osteopontin (OP), and runx2-were evaluated for their ability to distinguish OSA from other primary bone tumors. The 42 formalin-fixed, paraffin-embedded, primary canine bone tumors included 15 OSAs, 8 chondrosarcomas, 11 fibrosarcomas, and 8 histiocytic sarcomas. All 4 antibodies were highly sensitive for detection of osteosarcoma. ALP was the most sensitive at 100% and runx2 the most specific at 78%. Running ALP and runx2 in series resulted in a sensitivity of 87% and a specificity of 85%. This combination of immunomarkers resulted in a diagnostic panel for distinguishing osteosarcoma from other primary bone tumors.

Metastatic hepatocellular carcinoma to the bone diagnosed by fine needle aspiration in a veteran population

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and it may present initially with extrahepatic spread in 5%-15% cases. It most commonly metastasizes to lungs, lymph nodes and adrenal glands. Skeletal metastases from HCC are uncommon and carry a very poor prognosis.

METHODS

We retrospectively reviewed all fine needle aspiration (FNA) specimens of metastatic HCC at our institution from January 1994 to March 2021 using the SNOMED search computer option. Relevant clinical information was obtained from the review of patient's electronic medical records.

RESULTS

There were 36 FNAs of metastatic HCC over a period of 27 years. Six patients (16.7%) were found to have skeletal metastases. All six patients were males with a median age of 59 years (54-71 years) and their lesions were osteolytic. The most common site of metastases was vertebra (3/50%). Most patients (67%) had bone metastases as an initial presentation, without prior history of HCC. The mean survival after the diagnosis of skeletal metastases was only 8 months.

CONCLUSION

Detection of extrahepatic HCC to bone is important to avoid any unwanted surgical intervention. In our patient population, the most common site of skeletal metastases from HCC was vertebra, therefore in FNAs of vertebral lytic masses, metastatic HCC should be considered. On FNA, extrahepatic metastases of HCC can mimic other poorly differentiated tumors. They behave in an aggressive fashion, resulting in a grim prognosis. Cytological substrates can be used for future molecular testing, if needed.

Prognostic Analysis of HPV Status in Sinonasal Squamous Cell Carcinoma

Sinonasal squamous cell carcinoma (SNSCC) is a rare and aggressive malignancy with poor prognosis. Human papilloma virus (HPV) can induce SNSCC although its incidence and impact on patients’ outcomes remains unclear. We performed a retrospective cohort study of patients with SNSCC treated consecutively in a comprehensive cancer center. HPV status was determined with p16 immunohistochemistry followed by RNA in situ hybridization (RNAscope). The incidence, clinical characteristics, and oncologic outcomes of HPV+SNSCC were assessed. P16 prognostic value was evaluated. Fifty-nine patients were included. Eleven (18.6%) SNSCC were p16+ with five (8.4%) doubtful cases. RNAscope was positive in nine cases (15.2%). Patients with HPV+SNSCC were younger (p = 0.0298) with a primary tumor originating mainly in nasal fossa (p < 10−4). Pathologic findings were not different according to HPV status. Among patients who were curatively treated, overall survival was better for HPV+SNSCC (p = 0.022). No prognostic value of p16 expression was reported. Patients with HPV+SNSCC have better oncologic outcomes, probably due to earlier tumor stage with primary location predominantly in the nasal fossa, a more suitable epicenter to perform a surgical resection with clear margins. P16 expression seems not to be a good surrogate of HPV status in SNSCC.

A Quality Analysis of Bony Specimens for Optimal Ethylenediaminetetraacetic Acid (EDTA) Decalcification

Introduction: Weak acids, such as etheylenediaminetetraacetic acid (EDTA), chelate calcium ions from the surface of tissues, decalcifying slowly but preserving molecular structures for ancillary testing. There is a need for optimization of EDTA protocols for specimen decalcification. We studied the effects of EDTA on different types of bony specimens for quality assurance. Methods: Specimens included: proximal femur curettage (0.7 g), fibula shave (1 mm thick, 0.5 g), tibia shave (2 mm thick, 0.9 g), and femur 11-gauge core biopsies. Curettage and shave specimens were placed in formalin then EDTA (Newcomersupply, Middleton, WI, USA) with continuous stirring. Specimens were removed at 24, 48, 72, 96, and 120 hours. Core biopsies were processed in EDTA with heat at 4, 8, 12, and 16 hours. X-ray imaging (Kubtec Xpert 40, Stratford, CT, USA) was obtained. Histological processing was attempted and H&E slides compared to radiologic imaging. Results: Fibula and tibia sections showed appropriate radiolucency at 120 hours and 7 days, respectively. Curettage specimens showed radiolucency of medullary bone at 48 hours. Curettage and fibula sections showed quality histology at 96 hours and 120 hours, respectively. Quality tibia sections were obtained at 7 days, requiring one hour of additional block surface decalcification with 1% HCL solution. Medullary and cortical core biopsies showed quality histology at 12 and 16 hours with heat, respectively. Conclusion: Imaging can determine appropriate decalcification of bony specimens. Medullary bone undergoes more rapid decalcification in EDTA than cortical bone. EDTA decalcification is best used for curettage and core biopsy specimens.

[From an optimal management of bone tissue samples to a quality patients' care in 2022 : A new paradigm]

Bone tissue can be involved by primitive or metastatic tumors and requires a specific processing both at the department of pathology and during multidisciplinary meetings. The development of fine-needle percutaneous biopsies and of molecular techniques in bone tumor pathology requires a specific management. Moreover, decalcification of samples is crucial but can be deleterious if not controlled or not appropriate. The aim of this review is to provide recommendations for management and decalcification of bone tumor samples.

Molecular Characterization of Prostate Cancers in the Precision Medicine Era

Prostate cancer (PCa) therapy has been recently revolutionized by the approval of new therapeutic agents in the metastatic setting. However, the optimal therapeutic strategy in such patients should be individualized in the light of prognostic and predictive molecular factors, which have been recently studied: androgen receptor (AR) alterations, PTEN-PI3K-AKT pathway deregulation, homologous recombination deficiency (HRD), mismatch repair deficiency (MMRd), and tumor microenvironment (TME) modifications. In this review, we highlighted the clinical impact of prognostic and predictive molecular factors in PCa patients' outcomes, identifying biologically distinct subtypes. We further analyzed the relevant methods to detect these factors, both on tissue, i.e., immunohistochemistry (IHC) and molecular tests, and blood, i.e., analysis of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). Moreover, we discussed the main pros and cons of such techniques, depicting their present and future roles in PCa management, throughout the precision medicine era.

Cracking it - successful mRNA extraction for digital gene expression analysis from decalcified, formalin-fixed and paraffin-embedded bone tissue

With the advance of precision medicine, the availability of tumor tissue for molecular analysis has become a limiting factor. This is particularly the case for bone metastases which are frequently occurring in cancer types such as prostate cancer. Due to the necessary decalcification process it was long thought that transcriptome analysis will not be feasible from decalcified formalin-fixed, paraffin-embedded (DFFPE) in a large manner. Here we demonstrate that mRNA extraction from DFFPE is feasible, quick, robust and reproducible and that decalcification does not hamper subsequent gene expression analysis. This might assist in implementing transcriptome analysis from DFFPE into every day practice.

Calcifying pseudoneoplasm of neuroaxis (CAPNON): a comprehensive immunohistochemical and morphological characterization of five cases

Calcifying pseudoneoplasm of neuroaxis (CAPNON) is a rare lesion of the central nervous system with uncertain histogenesis. We further explored phenotypic spectrum of the entity with respect to possible histogenesis. We collected 5 cases of CAPNONs, performed a detailed morphological assessment, and performed an extensive immunohistochemical analysis (EMA, progesterone receptors, MUC4, SSTR2A, cytokeratin AE1/3, cytokeratin 18, GFAP, neurofilaments, desmin, nestin, synaptophysin, S100 protein, SOX10, CD56, Podoplanin, SATB2, ERG, CD45, and CD163) to elucidate the histogenesis. Furthermore, we performed NGS analysis of one case. The clinical course was benign in all cases. All lesions showed extensively calcified matrix in multilobular arrangement, with a palisade of osteoblast-like cells. Characteristic fibrohyaline matrix was notable in 4/5 cases, while one case was myxoid with rod-like calcifications. Metaplastic lamellar bone was present in 4/5 cases and psammoma bodies were present in 2/5 cases. In 4/5 cases, areas of entrapped glial tissue were present. Expression of EMA was focally present in 3/5 cases, SSTR2A and nestin in 2/5 cases, and progesterone receptor in 2/5 cases in rare cells. We did not observe concomitant expression of EMA, SSTR2A, and progesterone receptor in the same cellular subsets. In one case, NGS showed multiple chromosomal alterations and missense mutation in PIK3CA, attributable to the admixed meningothelial population compatible with meningioma. In another case, biphasic proliferation with myoepithelial phenotype was present. The lesions showed no lineage-specific immunoprofile. Additional pathology was identified in two cases, furthermore suggestive of a possible reactive origin of the lesion.

Reliability and Role of Mutation-specific H3F3A (Histone 3-3) G34W Immunohistochemistry to Differentiate Giant Cell Tumor of Bone From its Clinicoradiologic and Histologic Mimics: An Institutional Study

Giant cell tumor of bone (GCTB) is a benign neoplasm, which can sometimes be a diagnostic challenge, especially in small biopsies, due to its histologic benign and malignant mimics. We evaluated the role of H3.3 G34W immunohistochemistry (IHC) antibody in diagnosing GCTB and its role in differentiating it from its close histologic mimics. A total of 120 cases (80 cases of GCTB and 40 cases of histologic mimics) were retrieved and subjected to IHC. Of 80 cases of GCTB, 72 cases showed a positive nuclear immunoexpression, while all 40 cases of histologic mimics of GCTB showed a negative staining for H3.3 G34W IHC. Sensitivity and specificity of this mutation-specific antibody for diagnosis of GCTB was 90% and 100%, respectively, while, the positive predictive value and the negative predictive value were 100% and 83.3%, respectively. A positive expression of H3.3 G34W was seen in all 5 cases of GCTB, postdenosumab therapy, as well as, in all 3 cases of malignant giant cell tumor. The presented study showed that H3.3 G34W mutation-specific IHC is a reliable and specific marker for GCTB and can help distinguish it from the histologic mimics due to distinct therapeutic implications.

A Simple and Quick Method for Decalcification Using Mouse Tail as a Model for Preparation of Lymphedema Study

The disadvantage of 10% EDTA decalcification is a long time-consuming. It needs to identify a quick and straightforward decalcification method when the preparation of lymphedema models using mouse tail which was a sample of bone wrapped in other tissues. In the present study, mouse tail samples were decalcified in 10% EDTA at 25, 37, and 42°C, respectively, with continuous shaking (150 rpm/min). The histologic integrity of samples was evaluated by hematoxylin and eosin staining, and the preservation of antigenicity was tested by either immunohistochemistry or immunofluorescence. The decalcification was distinctly accelerated by temperature. Results of hematoxylin and eosin staining were similar among different temperature groups. Immunohistochemistry and immunofluorescence staining revealed almost no signals in samples decalcified at 42°C for 1 week. Clear signals were detected when samples were decalcified at 37 and 25°C.

Performances of single tube nested polymerase chain reaction and GeneXpert ultra on Formalin fixed paraffin embedded tissues in the diagnosis of tuberculous spondylodiscitis

INTRODUCTION

Tuberculous Spondylodiscitis is the most common form of musculoskeletal tuberculosis. Molecular techniques on fresh tissues are proved to improve the diagnosis of tuberculous spondylodiscitis and to allow a rapid diagnosis to initiate the treatment and prevent neurological complications.

OBJECTIVES

The objective of the present study was to assess the diagnostic performances of single tube nested PCR and GeneXpert ultra in the diagnosis of tuberculous spondylodiscitis on formalin fixed paraffin embedded tissues.

METHODS

This study included 63 tuberculous spondylodiscitis cases collected from June 2014 to January 2020 and corresponding to 27 definite tuberculous spondylodiscitis with positive microbiology, and 36 probable tuberculous spondylodiscitis, with histopathological, clinical and radiological findings consistent with tuberculous spondylodiscitis but with negative microbiology. The sensitivity, specificity, positive predictive value and negative predictive value of nested PCR and GeneXpert ultra were determined with reference to microbiology.

RESULTS

Nested PCR was positive in 47 (75%) cases: 26/27 definite tuberculous spondylodiscitis and 21/36 probable tuberculous spondylodiscitis. GeneXpert ultra was positive in only 6 (10%) cases corresponding to definite tuberculous spondylodiscitis. The sensitivity, specificity, positive predictive value and negative predictive value of nested PCR on formalin fixed paraffin embedded tissues were 96%, 100%, 100%, 83% respectively. For GeneXpert ultra, these rates were 22%, 100%, 100% and 25% respectively.

CONCLUSION

Nested PCR and GeneXpert ultra on formalin fixed paraffin embedded tissues are useful tools for the diagnosis of tuberculous spondylodiscitis, especially for cases where microbiological investigations were not carried out. Both techniques have excellent specificity but single tube nested PCR is more sensitive. Key Points • Molecular techniques are routinely performed on fresh tissues • GeneXpert and nested PCR on formalin fixed paraffin embedded tissues are reliable for the diagnosis of tuberculous spondylodiscitis • Nested PCR is more sensitive than Genexpert for diagnosing tuberculous spondylodiscitis.

Expression of BCL6 in paediatric B-cell acute lymphoblastic leukaemia and association with prognosis

B-cell lineage acute lymphoblastic leukaemia (B-ALL) is the most common paediatric malignancy. Transcription factor B-cell lymphoma 6 (BCL6) is essential to germinal centre formation and antibody affinity maturation and plays a major role in mature B-cell malignancies. More recently, it was shown to act as a critical downstream regulator in pre-BCR+ B-ALL. We investigated the expression of the BCL6 protein in a population-based cohort of paediatric B-ALL cases and detected moderate to strong positivity through immunohistochemistry in 7% of cases (8/117); however, only two of eight BCL6 cases (25%) co-expressed the ZAP70 protein. In light of these data, the subtype with active pre-BCR signalling constitutes a rare entity in paediatric B-ALL. In three independent larger cohorts with gene expression data, high BCL6 mRNA levels were associated with the TCF3-PBX1, Ph-like, NUTM1, MEF2D and PAX5-alt subgroups and the 'metagene' signature for pre-BCR-associated genes. However, higher-than-median BCL6 mRNA level alone was associated with favourable event free survival in the Nordic paediatric cohort, indicating that using BCL6 as a diagnostic marker requires careful design, and evaluation of protein level is needed alongside the genetic or transcriptomic data.

Molecular biomarker testing for non-small cell lung cancer: consensus statement of the Korean Cardiopulmonary Pathology Study Group

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

Radiology-pathology correlation for bone and soft tissue tumors or tumor-like masses: single institutional experience after implementation of a weekly conference

OBJECTIVES

To determine the frequency of non-diagnostic and discordant results from bone and soft tissue biopsies performed at our institution over a 3-year period and to investigate whether implementation of a weekly musculoskeletal radiology-pathology correlation conference decreased the time to appropriate patient management in cases of discordance.

METHODS

Consecutive image-guided core needle biopsy results obtained over a 12 month period of time were reviewed in a retrospective fashion. Following implementation of the correlation conference, subsequent consecutive image-guided core needle biopsy results obtained over a 26 month period of time were reviewed in a prospective fashion. For non-diagnostic and discordant cases, the time in days from date of availability of the biopsy result to date of documentation of a specific follow-up action plan was recorded.

RESULTS

Diagnostic yield was 96.5% and 94.9% for the retrospective and prospective periods, respectively. There were four discordant results in the retrospective cohort (1.7%) and seven discordant results in the prospective cohort (2.1%). Following implementation of the weekly correlation conference, there was significant decrease (p < 0.05) in median time from a discordant biopsy result to follow-up action plan. There were no unnecessary surgeries, litigation, or other unfavorable consequences in either cohort.

CONCLUSION

Image-guided core needle biopsies of bone and soft tissue provide high diagnostic yield, often with specific diagnoses. The statistically significant decrease in number of days to follow-up action plan for discordant results suggests radiology-pathology review has a positive impact on patient care. Subjective benefits from communication and educational standpoints are also noteworthy.

Fast and accurate protocol for histology and immunohistochemistry reactions in temporomandibular joint of rats

OBJECTIVE

Propose a standard, fast and accurate protocol for the processing of the temporomandibular joint (TMJ) of adults' rats for histology and immunohistochemistry reactions.

DESIGN

Wistar male rats were perfused with paraformaldehyde (4 %). The heads were fixed in formaldehyde 10 % solution for 48 h. After that, the heads were sectioned in a sagittal plane and fixed for plus 48 h. Decalcification was performed using 20 % formic acid for 96 h and delimitation of TMJ area was done. Detailed methodology to a standard extraction and processing of TMJ to histological sections is described. Different buffers, equipment, temperature and time were tested to optimize immunostaining. Morphological preservation and antigenicity were evaluated by hematoxylin and eosin staining and immunohistochemistry reaction.

RESULTS

The current findings demonstrated that TMJ fixed in 10 % formaldehyde and decalcified in 20 % formic acid optimized decalcification processing time with preservation of cell morphology. Antigen retrieval with citrate buffer in pressure cooker (2 min at 100 °C and 5 min at room temperature) demonstrated the best protocol to preservation of the structures of TMJ.

CONCLUSIONS

This work demonstrates in detail a methodology of a fast and accurate TMJ processing for histology and immunohistochemistry reactions that guarantee tissue integrity and quality of staining.

'SMASH' recommendations for standardised microscopic arthritis scoring of histological sections from inflammatory arthritis animal models

Animal models for inflammatory arthritides such as rheumatoid arthritis (RA) and psoriatic arthritis are widely accepted and frequently used to identify pathological mechanisms and validate novel therapeutic strategies. Unfortunately, many publications reporting on these animal studies lack detailed description and appropriate assessment of the distinct histopathological features of arthritis: joint inflammation, cartilage damage and bone erosion. Therefore, the European consortium BeTheCure, consisting of 38 academic and industrial partners from 15 countries, set as goal to standardise the histological evaluation of joint sections from animal models of inflammatory arthritis. The consensual approach of a task force including 16 academic and industrial scientists as well as laboratory technicians has resulted in the development of the Standardised Microscopic Arthritis Scoring of Histological sections (‘SMASH’) recommendations for a standardised processing and microscopic scoring of the characteristic histopathological features of arthritis, exemplified by four different rodent models for arthritis: murine collagen-induced arthritis, collagen–antibody-induced arthritis, human tumour necrosis factor transgenic Tg197 mice and rat pristane-induced arthritis, applicable to any other inflammatory arthritis model. Through standardisation, the SMASH recommendations are designed to improve and maximise the information derived from in vivo arthritis experiments and to promote reproducibility and transparent reporting on such studies. In this manuscript, we will discuss and provide recommendations for analysis of histological joint sections: identification of the regions of interest, sample preparation, staining procedures and quantitative scoring methods. In conclusion, awareness of the different features of the arthritis pathology in animal models of inflammatory arthritis is of utmost importance for reliable research outcome, and the standardised histological processing and scoring methods in these SMASH recommendations will help increase uniformity and reproducibility in preclinical research on inflammatory arthritis.

Large fragment demineralization: an alternative pretreatment for forensic DNA typing of bones

In forensic genetics, the analysis of postmortem bones is one of the most challenging due to the low quantity of degraded endogenous DNA. The most widely used approach for sample preparation, in those cases, is pulverizing the bone. However, processing pulverized bone is extremely delicate, requiring strict laboratory conditions and operating procedures. In fact, several recent publications have focused on non-powder approaches. The objectives of this study were, thus, to validate a non-powder protocol for DNA extraction from forensic bones and an alternative pretreatment, large fragment demineralization (LFD). Thirty human femurs and tibiae received by the Legal Medicine Institute of Brescia, Italy, were included in the study. Bone powder and one transversal section of the diaphysis were sampled from each bone. DNA extraction from the powder was carried out using PrepFiler BTA (BTA), while the transversal section was submitted to the alternative demineralizing pretreatment (LFD) followed by DNA extraction using the QIAamp DNA Investigator. DNA extracts were assessed for human DNA quantity and degradation by means of a validated in-house qPCR assay and amplified with commercial kits. Inhibition assessment was carried out through Quality Sensor analysis using 24plex QS Kit. The differences in quantity, quality of human DNA, and number of alleles detected between both methods were comparable and not statistically significant. We propose the use of the LFD protocol as a complementary approach capable of confirming the genotypes or detect alleles not observed using BTA, without the need for pulverization.

An Ion-exchange Bone Demineralization Method for Improved Time, Expense, and Tissue Preservation

Here, we describe an ethylenediaminetetraacetic acid (EDTA)-based bone demineralization procedure that uses cation-exchange resin and dialysis tubing. This method does not require solution changes or special equipment, is faster than EDTA alone, is cost-effective, and is environmentally friendly. Like other EDTA-based methods, this procedure yields superior tissue preservation than formic acid demineralization. Greater protein antigenicity using EDTA as opposed to formic acid has been described, but we also find significant improvements in carbohydrate-based histological staining. Histological staining using this method reveals cartilage layers that are not distinguishable with formic acid demineralization. Carbohydrate preservation is relevant to many applications of bone demineralization, including the assessment of osteoarthritis from bone biopsies and the use of demineralized bone powder for tissue culture and surgical implants. The improvements in time, expense, and tissue quality indicate this method is a practical and often superior alternative to formic acid demineralization.

A case of spindle cell dominant histiocytic sarcoma showing a complete remission after first-line chemotherapy with doxorubicin and ifosfamide

Histiocytic sarcoma (HS), an extremely rare malignancy, usually follows a progressive time course, and patients die within two years of diagnosis. At present, there is no consensus for effective chemotherapy. We report the case of a 54-year-old man who presented with low back pain and left hip joint pain. Imaging for the pain revealed multiple lesions in the mediastinum, vertebral bodies, and left ilium. Biopsies of the mediastinal and vertebral lesions yielded a diagnosis of soft tissue sarcoma. He received standard chemotherapy for sarcoma with doxorubicin and ifosfamide, as the initial pathological diagnosis was soft tissue sarcoma. This is called AI therapy and commonly used for soft tissue sarcoma. Palliative radiation therapy to the left iliac lesion was added for pain control. Complete remission (CR) was achieved after two courses of AI therapy. Subsequent immunopathological examination revealed that the tumor was spindle cell dominant HS. CR was maintained for more than three years. To the best of our knowledge, this is the first report that a CR was achieved by AI therapy as first-line treatment for spindle cell dominant HS, combined with focal bone palliative irradiation. AI therapy could be an effective option as chemotherapy for HS.