The Alveolar Variant of Lobular Carcinoma and Its Mimickers: A Case Series.

Invasive lobular carcinoma (ILC) is the most common special type of invasive breast cancer (IBC), accounting for 5-15% of IBCs. The distinct histomorphology of ILC reflects a special tumor biology, the hallmark of which is the lack of E-cadherin expression. However, the occasional presence of E-cadherin expression and the presence of IBC of no special type (IBC, NST)-like morphologies in ILC and vice versa make the diagnosis challenging.  We present two cases of the alveolar variant of ILC, a diagnostically challenging entity. The first case is an 81-year-old female with two discrete right breast masses at 1 o'clock and 9 o'clock positions.  The second case is a 61-year-old female with two discrete left breast masses located at 11 o'clock and 12 o'clock positions. Core needle biopsies and subsequent mastectomy were performed in both cases. On histology, three tumor foci were identified in the first case. The 1 o'clock focus showed IBC, NST, grade 3/3, ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). The 9 o'clock focus revealed ILC, classic and alveolar variants, grade 2/3, while a nearby third incidental focus was ILC, alveolar variant, both supported by lack of E-cadherin and ß-catenin immunostaining.  The second case showed ILC, alveolar variant, grade 1 with LCIS component in the 11 o'clock lesion on both biopsy and mastectomy specimens. The lesion at the 12 o'clock position was diagnosed as IBC, NST, grade 2 with high-grade DCIS and LCIS components.  It is challenging to distinguish the alveolar variant of ILC from IBC, NST, and in situ lesions because of the overlapping morphology and occasional E-cadherin expression. Altered adherence of lobular cells may also be due to loss of α-, ß-, and γ-catenins, and cytoplasmic re-localization of p120-catenin. Therefore, in ILC, the lack of ß-catenin can be used as an adjunct along with E-cadherin. Myoepithelial markers such as p63 and smooth muscle myosin heavy chain (SMMHC) can be used to distinguish the alveolar variant of ILC from LCIS.

DNA mismatch repair defect and intratumor heterogeneous deficiency differently impact immune responses in diffuse large B-cell lymphoma.

Deficient (d) DNA mismatch repair (MMR) is a biomarker predictive of better response to PD-1 blockade immunotherapy in solid tumors. dMMR can be caused by mutations in MMR genes or by protein inactivation, which can be detected by sequencing and immunohistochemistry, respectively. To investigate the role of dMMR in diffuse large B-cell lymphoma (DLBCL), MMR gene mutations and expression of MSH6, MSH2, MLH1, and PMS2 proteins were evaluated by targeted next-generation sequencing and immunohistochemistry in a large cohort of DLBCL patients treated with standard chemoimmunotherapy, and correlated with the tumor immune microenvironment characteristics quantified by fluorescent multiplex immunohistochemistry and gene-expression profiling. The results showed that genetic dMMR was infrequent in DLBCL and was significantly associated with increased cancer gene mutations and favorable immune microenvironment, but not prognostic impact. Phenotypic dMMR was also infrequent, and MMR proteins were commonly expressed in DLBCL. However, intratumor heterogeneity existed, and increased DLBCL cells with phenotypic dMMR correlated with significantly increased T cells and PD-1+ T cells, higher average nearest neighbor distance between T cells and PAX5+ cells, upregulated immune gene signatures, LE4 and LE7 ecotypes and their underlying Ecotyper-defined cell states, suggesting the possibility that increased T cells targeted only tumor cell subsets with dMMR. Only in patients with MYC¯ DLBCL, high MSH6/PMS2 expression showed significant adverse prognostic effects. This study shows the immunologic and prognostic effects of genetic/phenotypic dMMR in DLBCL, and raises a question on whether DLBCL-infiltrating PD-1+ T cells target only tumor subclones, relevant for the efficacy of PD-1 blockade immunotherapy in DLBCL.

PathoDuet: Foundation models for pathological slide analysis of H&E and IHC stains.

Large amounts of digitized histopathological data display a promising future for developing pathological foundation models via self-supervised learning methods. Foundation models pretrained with these methods serve as a good basis for downstream tasks. However, the gap between natural and histopathological images hinders the direct application of existing methods. In this work, we present PathoDuet, a series of pretrained models on histopathological images, and a new self-supervised learning framework in histopathology. The framework is featured by a newly-introduced pretext token and later task raisers to explicitly utilize certain relations between images, like multiple magnifications and multiple stains. Based on this, two pretext tasks, cross-scale positioning and cross-stain transferring, are designed to pretrain the model on Hematoxylin and Eosin (H&E) images and transfer the model to immunohistochemistry (IHC) images, respectively. To validate the efficacy of our models, we evaluate the performance over a wide variety of downstream tasks, including patch-level colorectal cancer subtyping and whole slide image (WSI)-level classification in H&E field, together with expression level prediction of IHC marker, tumor identification and slide-level qualitative analysis in IHC field. The experimental results show the superiority of our models over most tasks and the efficacy of proposed pretext tasks. The codes and models are available at https://github.com/openmedlab/PathoDuet.

Multiplexed immunohistochemical analysis of the immune microenvironment of biliary tract cancers pre- & post-neoadjuvant chemotherapy: case series.

Background: Neoadjuvant chemotherapy (NACT) is increasingly being used in the management of locally advanced biliary tract cancer (BTC). The evidence suggests a contributing role of tumor infiltrating immune cells in the prognosis and response. We set out to characterize immune modulation of tumor immune microenvironment in BTC following NACT. Case Description: Patients with BTC who underwent diagnostic biopsy, then NACT then resection between 2014-2018 were identified. Multiplexed immunohistochemical consecutive staining on single slide (MICSSS) analysis was performed with a series of immune markers to characterize T-cells, immune checkpoints etc. on pre- & post-NACT tumor tissue. Density was calculated for each marker. The final analysis included five patients. Median age was 48 (range, 41-56) years, with 4 female, 4 intrahepatic cholangiocarcinoma and 1 gallbladder. All patients received gemcitabine/cisplatin as NACT (median of 5 cycles). Median time from diagnosis to surgery was 4.3 (range, 1.4-7.8) months. All patients were mismatch repair proficient (pMMR). NACT on average produced a depletion of all immune markers. Given small sample size, each patient was considered their own control and changes in mean cell densities post-NACT were calculated. Patient #2 with a 40-fold increase in PD-L1 expression & 5-fold decrease in CD8:FOXP3 ratio after NACT notably had the shortest disease-free interval (DFI). Patient #3 with the longest DFI had the largest increase in CD8:FOXP3 by about 8-fold with a decrease in PD-L1. Conclusions: Preliminary results suggest NACT may differentially modulate various compartments of the immune tumor contexture despite overall cell depletion. Future studies should focus on strategies to expand immune modulation of tumor microenvironment, including immune-oncology agents to augment the effects of chemotherapy.

Real-world genetic testing outcomes of pan-cancer testing for mismatch repair deficiency.

BACKGROUND: In 2017, the Food and Drug Administration approved pembrolizumab for treatment of any mismatch repair-deficient (dMMR) tumor making MMR immunohistochemistry (IHC) testing beneficial for all tumor types. For the first time, MMR IHC was not performed exclusively to screen for Lynch syndrome (LS). METHODS: In this study, all MMR IHC reports issued between 2017 and 2021 at an academic hospital were reviewed and completion of genetic testing was determined through chart review. Colorectal cancers (CRCs), endometrial cancers (ECs), and noncancerous lesions were excluded. RESULTS: Between 2017 and 2021, MMR IHC was completed in 1939 patients with a malignancy other than CRC or EC. Absent or weak staining for at least one MMR protein was detected in 115 (5.9%) patients and 59 (51%) of those completed germline genetic testing. Overall, the identification rate of LS in this cohort was 0.72%, which is similar to the rate in our previously reported CRC and EC universal screening cohort. A diagnosis of LS was most commonly made in patients with dMMR brain (18.75%) and small intestinal cancers (10.20%). Five additional patients were found to carry a pathogenic variant in a non-LS gene. CONCLUSIONS: Pan-cancer MMR testing for pembrolizumab consideration can identify LS cases at a rate similar to universal CRC and EC screening programs. A persistent challenge is subsequent uptake of genetic testing. MMR testing should be prioritized in brain and small intestinal tumors, and multigene panel testing is recommended in patients with dMMR, as unexpected pathogenic variants in non-LS genes were found as frequently as LS gene variants.

Unusual metastases to the breast from different extramammary malignancies: a multimodality imaging approach in a case series.

Extramammary metastases are uncommon and usually related to a poor prognosis, but the radiologist can suspect the diagnosis based on the patient's clinical history and specific imaging findings. Several imaging procedures may be used to evaluate breast metastases from different extramammary malignancies, including mammography, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography-CT (PET-CT). The clinical and imaging presentation of these metastases is contingent upon how the illness spreads, however, they have the potential to resemble either benign or malignant breast tumors. Metastases that disseminate hematologically tend to appear as a single round or oval mass with circumscribed margins. Sonographically, they are usually hypoechoic, and with CT or MRI, they usually enhance. Lymphatic dissemination, for example, frequently reveals significant asymmetry with skin thickening and diffuse breast edema, which is compatible with an inflammatory breast carcinoma. Knowing the many types of cancers that have the potential to spread to the breast as well as being able to accurately diagnose them is crucial to prevent a needless mastectomy and provide guidance for subsequent treatment. The purpose of this article is to provide a better understanding of the imaging features and immunohistochemistry (IHC) of secondary tumors of the breast by presenting eight distinctive cases, which will enable radiologists to recognize this entity.

TIM-3/CD68 double-high expression in Glioma: Prognostic characteristics and potential therapeutic approaches.

BACKGROUND: Immunotherapy has revolutionized the treatment of various types of tumors, but there has been no breakthrough in the treatment of gliomas. The aim of this study is to discover valuable immunotherapy target in glioma, analyze its expression in glioma and the related microenvironment, explore potential immunotherapy strategies, and propose new possibilities for the treatment of gliomas. METHODS: Immunohistochemistry (IHC) and multiplex fluorescence immunohistochemistry (mIHC) were used to analyze the expression of common immune markers and checkpoints in 187 glioma patients from Sun Yat-sen University Caner Center (SYSUCC). Bioinformatics analysis was used to examine the expression of TIM-3 in different macrophages using the Chinese Glioma Genome Atlas (CGGA) single-cell sequencing database. The Kaplan-Meier curve was used to predict the prognostic value of samples with high TIM-3 and CD68 expression. The R package was used to analyze the somatic mutation status and the sensitivity of small molecule inhibitors in TIM-3/CD68 double-high expression samples. RESULTS: TIM-3 is a relatively highly expressed immune checkpoint in glioma. Unlike other tumors, TIM-3 is mainly expressed on macrophages in the glioma microenvironment. TIM-3/CD68 double-high expression suggests poor survival in glioma and may be a new upgrade marker in both IDH-mutant glioma and IDH-wildtype low-grade glioma (LGG) glioma (P < 0.01). Exploring the combination of TIM-3 inhibitors and p38 MAPK inhibitor may be a potential treatment direction for TIM-3/CD68 double high expression gliomas in the future. CONCLUSIONS: The combination of TIM-3 and CD68 holds significant importance as a potential target for both prognosis and therapeutic intervention in glioma.

The Clinical Significance of CRNDE Gene Methylation, Polymorphisms, and CRNDEP Micropeptide Expression in Ovarian Tumors.

CRNDE is an oncogene expressed as a long non-coding RNA. However, our team previously reported that the CRNDE gene also encodes a micropeptide, CRNDEP. The amino acid sequence of CRNDEP has recently been revealed by other researchers, too. This study aimed to investigate genetic alterations within the CRNDEP-coding region of the CRNDE gene, methylation profiling of this gene, and CRNDEP expression analysis. All investigations were performed on clinical material from patients with ovarian tumors of diverse aggressiveness. We found that CRNDEP levels were significantly elevated in highly aggressive tumors compared to benign neoplasms. Consistently, a high level of this micropeptide was a negative, independent, prognostic, and predictive factor in high-grade ovarian cancer (hgOvCa) patients. The cancer-promoting role of CRNDE(P), shown in our recent study, was also supported by genetic and epigenetic results obtained herein, revealing no CRNDEP-disrupting mutations in any clinical sample. Moreover, in borderline ovarian tumors (BOTS), but not in ovarian cancers, the presence of a single nucleotide polymorphism in CRNDE, rs115515594, significantly increased the risk of recurrence. Consistently, in BOTS only, the same genetic variant was highly overrepresented compared to healthy individuals. We also discovered that hypomethylation of CRNDE is associated with increased aggressiveness of ovarian tumors. Accordingly, hypomethylation of this gene's promoter/first exon correlated with hgOvCa resistance to chemotherapy, but only in specimens with accumulation of the TP53 tumor suppressor protein. Taken together, these results contribute to a better understanding of the role of CRNDE(P) in tumorigenesis and potentially may lead to improvements in screening, diagnosis, and treatment of ovarian neoplasms.

Monitoring mouse papillomavirus-associated cancer development using longitudinal Pap smear screening.

A substantial percentage of the population remains at risk for cervical cancer due to pre-existing human papillomavirus (HPV) infections, despite prophylactic vaccines. Early diagnosis and treatment are crucial for better disease outcomes. The development of new treatments heavily relies on suitable preclinical model systems. Recently, we established a mouse papillomavirus (MmuPV1) model that is relevant to HPV genital pathogenesis. In the current study, we validated the use of Papanicolaou (Pap) smears, a valuable early diagnostic tool for detecting HPV cervical cancer, to monitor disease progression in the MmuPV1 mouse model. Biweekly cervicovaginal swabs were collected from the MmuPV1-infected mice for viral DNA quantitation and cytology assessment. The Pap smear slides were evaluated for signs of epithelial cell abnormalities using the 2014 Bethesda system criteria. Tissues from the infected mice were harvested at various times post-viral infection for additional histological and virological assays. Over time, increased viral replication was consistent with higher levels of viral DNA, and it coincided with an uptick in epithelial cell abnormalities with higher severity scores noted as early as 10 weeks after viral infection. The cytological results also correlated with the histological evaluation of tissues harvested simultaneously. Both immunocompromised and immunocompetent mice with squamous cell carcinoma (SCC) cytology also developed vaginal SCCs. Notably, samples from the MmuPV1-infected mice exhibited similar cellular abnormalities compared to the corresponding human samples at similar disease stages. Hence, Pap smear screening proves to be an effective tool for the longitudinal monitoring of disease progression in the MmuPV1 mouse model. IMPORTANCE: Papanicolaou (Pap) smear has saved millions of women's lives as a valuable early screening tool for detecting human papillomavirus (HPV) cervical precancers and cancer. However, more than 200,000 women in the United States alone remain at risk for cervical cancer due to pre-existing HPV infection-induced precancers, as there are currently no effective treatments for HPV-associated precancers and cancers other than invasive procedures including a loop electrosurgical excision procedure (LEEP) to remove abnormal tissues. In the current study, we validated the use of Pap smears to monitor disease progression in our recently established mouse papillomavirus model. To the best of our knowledge, this is the first study that provides compelling evidence of applying Pap smears from cervicovaginal swabs to monitor disease progression in mice. This HPV-relevant cytology assay will enable us to develop and test novel antiviral and anti-tumor therapies using this model to eliminate HPV-associated diseases and cancers.

Changes in the tumour microenvironment mark the transition from serous borderline tumour to low-grade serous carcinoma.

Low-grade serous ovarian carcinoma (LGSC) is a rare and lethal subtype of ovarian cancer. LGSC is pathologically, biologically, and clinically distinct from the more common high-grade serous ovarian carcinoma (HGSC). LGSC arises from serous borderline ovarian tumours (SBTs). The mechanism of transformation for SBTs to LGSC remains poorly understood. To better understand the biology of LGSC, we performed whole proteome profiling of formalin-fixed, paraffin-embedded tissue blocks of LGSC (n = 11), HGSC (n = 19), and SBTs (n = 26). We identified that the whole proteome is able to distinguish between histotypes of the ovarian epithelial tumours. Proteins associated with the tumour microenvironment were differentially expressed between LGSC and SBTs. Fibroblast activation protein (FAP), a protein expressed in cancer-associated fibroblasts, is the most differentially abundant protein in LGSC compared with SBT. Multiplex immunohistochemistry (IHC) for immune markers (CD20, CD79a, CD3, CD8, and CD68) was performed to determine the presence of B cells, T cells, and macrophages. The LGSC FAP+ stroma was associated with greater abundance of Tregs and M2 macrophages, features not present in SBTs. Our proteomics cohort reveals that there are changes in the tumour microenvironment in LGSC compared with its putative precursor lesion, SBT. These changes suggest that the tumour microenvironment provides a supportive environment for LGSC tumourigenesis and progression. Thus, targeting the tumour microenvironment of LGSC may be a viable therapeutic strategy. © 2024 The Pathological Society of Great Britain and Ireland.

Immunotherapy Applications for Thymine Dimers and WT1 Antigen in Renal Cancers: A Comparative Statistical Analysis.

Renal cell carcinoma (RCC) remains incurable in advanced stages. Biomarkers have proven to be quite useful in cancer therapeutics. Herein, we provide a comparative/integrative statistical analysis of seminal immunohistochemistry (IHC) findings for Wilms' Tumor 1 antigen (WT1) and thymine dimers (TDs), emerging as atypical, yet promising, potential biomarkers for RCCs. We assessed WT1/TD reactivity in adult RCC tumor cells, tumor microenvironment (TME), and tumor-adjacent healthy renal tissue (HRT). WT1 positivity was scarce and strictly nuclear in tumor cells, whereas TD-reactive tumor tissues were prevalent. We report statistically significant positive correlations between the density of reactive RCC cellularity and the intensity of nuclear staining for both biomarkers (WT1 - rho = 0.341, p-value = 0.036; TDs - rho = 0.379, p-value = 0.002). RCC stromal TME TD-positivity was much more frequent than WT1 reactivity, apparently proportional to that of the proper RCC cellularity and facilitated by extensive RCC inflammatory infiltration. TDs exhibited nuclear reactivity for most TME cell lines, while RCC TME WT1 expression was rare and inconsistent. In HRTs, TDs were entirely restricted to renal tubular cells, the likely cellular progenitor of most conventional RCC subtypes. In lieu of proper validation, these early findings have significant implications regarding the origins/biology of RCCs and may inform RCC therapeutics, both accounting for the high frequency of immunotherapy-permissive frameshift indels in RCCs, but also hinting at novel predictive clinical tools for WT1-targeted immunotherapy. Overall, the current study represents a meek yet hopefully significant step towards understanding the molecular biology and potential therapeutic targets of RCCs.

Expression of the Folate Receptor Proteins FOLR1 and FOLR2 in Correlation With Clinicopathological Variables of Gastric Cancer.

INTRODUCTION: Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, owing to its aggressive nature and poor prognosis. The role of folate receptors, particularly folate receptor 1 (FOLR1) and folate receptor 2 (FOLR2), in cancer has been increasingly recognized due to their overexpression in various malignancies including gastric cancer, and its potential implications in cancer progression, treatment resistance and as therapeutic targets. OBJECTIVE: To evaluate the expression patterns of FOLR1 and FOLR2 in GC patients' tissue and blood specimens and to correlate these patterns with clinicopathological variables. METHODS: A total of 58 gastric cancer patients were enrolled at the Regional Cancer Centre (RCC) from March 2017 to March 2020. Immunohistochemical analysis was performed to examine the expression of FOLR1 and FOLR2 in formalin-fixed paraffin-embedded (FFPE) tissue samples. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to analyze FOLR1 and FOLR2 expression in blood samples. Statistical analyses were conducted using chi-square tests, independent T-tests, and Kaplan-Meier survival analysis. RESULTS: FOLR1 and FOLR2 were overexpressed in 82.76% and 70.69% of gastric cancer tissues, respectively. High expression levels of FOLR1 were significantly associated with the diffuse type of gastric cancer (p<0.005). qRT-PCR showed significant overexpression of FOLR1 in gastric cancer blood samples compared to control samples, with a median fold change of approximately 14.18 times. Conversely, FOLR2 was significantly underexpressed in gastric cancer samples, with a fold change of 0.30. However, no significant correlation was found between FOLR2 expression and the clinicopathological features. The overall survival analysis did not show a significant difference in survival rates based on the expression levels of FOLR1 and FOLR2. CONCLUSIONS: This study highlights the differential expression patterns of FOLR1 and FOLR2 in gastric cancer and underscores the complexity of their roles in cancer biology. While FOLR1 shows potential as a biomarker for gastric cancer due to its overexpression, further studies are needed to fully elucidate the therapeutic and prognostic implications of folate receptors in gastric cancer.

Multimodal Mass Spectrometry Imaging of an Osteosarcoma Multicellular Tumour Spheroid Model to Investigate Drug-Induced Response.

A multimodal mass spectrometry imaging (MSI) approach was used to investigate the chemotherapy drug-induced response of a Multicellular Tumour Spheroid (MCTS) 3D cell culture model of osteosarcoma (OS). The work addresses the critical demand for enhanced translatable early drug discovery approaches by demonstrating a robust spatially resolved molecular distribution analysis in tumour models following chemotherapeutic intervention. Advanced high-resolution techniques were employed, including desorption electrospray ionisation (DESI) mass spectrometry imaging (MSI), to assess the interplay between metabolic and cellular pathways in response to chemotherapeutic intervention. Endogenous metabolite distributions of the human OS tumour models were complemented with subcellularly resolved protein localisation by the detection of metal-tagged antibodies using Imaging Mass Cytometry (IMC). The first application of matrix-assisted laser desorption ionization-immunohistochemistry (MALDI-IHC) of 3D cell culture models is reported here. Protein localisation and expression following an acute dosage of the chemotherapy drug doxorubicin demonstrated novel indications for mechanisms of region-specific tumour survival and cell-cycle-specific drug-induced responses. Previously unknown doxorubicin-induced metabolite upregulation was revealed by DESI-MSI of MCTSs, which may be used to inform mechanisms of chemotherapeutic resistance. The demonstration of specific tumour survival mechanisms that are characteristic of those reported for in vivo tumours has underscored the increasing value of this approach as a tool to investigate drug resistance.

Immunohistochemical Expression of Programmed Death Ligand- 1 (PD-L1) in Colorectal Carcinoma; A Cross-sectional Study.

Background & Objective: Colorectal carcinoma (CRC) is one of the most common cancers worldwide. The interaction of programmed cell death receptor 1 (PD-1) and programmed death ligand 1 (PD-L1) plays an important role by inhibiting the immune mechanism by which cancer cells escape antitumor immunity. Immunotherapy using checkpoint inhibitors is a growing treatment modality in many cancers; one such is anti-PD1/PD-L1. The present study aimed to study the immunohistochemical (IHC) expression of PD-L1 in CRC and its association with various known clinicopathological parameters. Methods: This study was a 2-year prospective study and included 34 colectomy specimens diagnosed as colorectal adenocarcinoma. The expression of PD-L1 was evaluated on tumoral cells and tumor-infiltrating immune cells (TIICs) and was correlated with various clinicopathological parameters. Results: Immunohistochemical expression of PD-L1 on tumoral cells and tumor microenvironment in CRC revealed positivity in 17.65% of cases each. The PD-L1 expression on tumoral cells was associated with lymphovascular invasion (LVI) and perineural invasion (PNI) with P- values of 0.012 and 0.005, respectively, while PD-L1 expression on TIICs was associated with tumor budding with a P-value of 0.022. Conclusion: IHC expression of PD-L1 on tumoral cells and immune cells may be associated with some known poor prognostic factors. Since anti-PD1/PD-L1 is used for targeted therapy, it may be beneficial and economically feasible to evaluate PD-L1 in CRC and establish its role as a prognostic factor.

Diagnostic utility of anti-thyroid peroxidase immunohistochemistry in the identification of papillary thyroid carcinoma.

The routine histomorphological assessment of follicular thyroid neoplasms has been subject to interobserver or intraobserver variability among histopathologists. Anti-thyroid peroxidase (anti-TPO) has emerged as a useful immunohistochemical (IHC) marker, with its expression lost in papillary thyroid carcinoma (PTC). Our study aims to determine the diagnostic accuracy of anti-TPO IHC expression in the identifying PTC and its variants, particularly the Follicular variant of papillary thyroid carcinoma (FVPTC), with H&E assessment as the gold standard. Anti-TPO IHC (DAKO-MoAb47) was performed on 110 cases, including 76 malignant tumors (classic PTC, FVPTC, follicular carcinoma (FC), and oncocytic carcinoma (OC)) and 34 benign tumors (non-invasive follicular tumor with papillary-like nuclear features (NIFTP) and follicular adenoma (FA)). The loss of expression in more than or equal to 51 % of thyrocytes was considered suggestive of a PTC profile. The sensitivity of the loss of anti-TPO expression for identifying PTC among all carcinomas was 61.7 %, specificity was 75 %, positive predictive value was 90.2 %, negative predictive value was 34.2 %, and accuracy was 64.4 %. The loss of anti-TPO IHC expression combined with routine H&E assessment, supports the identification of PTC and its variants.

Cytoplasmic PPARγ Significantly Correlates With P53 Immunohistochemical Expression and Tumor Size in Localized Tenosynovial Giant Cell Tumor.

BACKGROUND: Tenosynovial giant cell tumor (TGCT) is a monoarticular fibrohistiocytic benign or locally aggressive soft tissue tumor that originates from the synovium of joints, bursae, and tendon sheaths. It has an inflammatory neoplastic nature, with a clinical presentation ranging from pain, swelling, stiffness, and limited range of movement to joint instability and blockage. Its uncommon incidence leads to a poorly understood pathogenesis. Localized forms of TGCT (LTGCT) can cause significant morbidity, interfere with daily patient activities, and decrease the patient's quality of life in challenging cases. This study aimed to investigate the immunohistochemical expression of PPARγ (peroxisome proliferator-activated receptor gamma) and P53 in LTGCT to understand the disease better and offer potential therapeutic targets. METHODS: The study is cross-sectional, in which 27 LTGCT cases were collected from the Pathology Department, Faculty of Medicine, Cairo University, Cairo, Egypt. Solitary and multiple LTGCT cases retrieved between January 2018 and December 2022 were included, and immunohistochemically stained with anti-PPARγ and P53 antibodies. The TGCT samples were excluded if they were insufficient for sectioning, processing, and interpretation, over-fixed, had process artifacts, or were of the diffuse TGCT type. Scoring of stain expression was performed by ImageJ (National Institutes of Health, Bethesda, MD) analysis using the threshold method and was expressed in percent area/high power field. Clinicopathological correlations were analyzed. RESULTS: All the 27 collected LTGCT cases were located in the small joints of patients' hands. Cases with solitary LGTCTs constituted 55.6% (n = 15), while 44.4% (n = 12) had multiple LTGCTs related to one affected site/case (e.g., multiple tumors in one finger). PPARγ was expressed in the cytoplasm of mononuclear and multinucleated tumor cells and foamy histiocytes, while P53 expression was mainly in mononuclear cells' nuclei. PPARγ significantly correlated with P53 expression (r = 0.9 and P = 0.000). PPARγ (r = 0.4 and P = 0.02) and P53 (r = 0.5 and P = 0.01) were positively correlated with tumor size. Only P53 expression was positively correlated with tumor multiplicity (r = 0.4 and P = 0.03). Using the receiver operating characteristic curve test, the P53 cutoff score detecting the multiplicity of TGCTs was ≥20.5%, with a 75% sensitivity and 80% specificity. CONCLUSION: PPARγ and P53 have a significant role in LTGCT growth, while P53 plays a role in tumor multiplicity. They can be possible targets in LTGCTs unfit for excision.

Gingival Carcinoma Cuniculatum: A Case Series of Seven Cases with Emphasis on Immunohistochemical and Histochemical Features.

Oral carcinoma cuniculatum (CC) is a rare distinct variant of oral squamous cell carcinoma (OSCC) displaying unique clinical and histopathological features. CC is a locally aggressive malignancy with lower metastatic potential and has a tendency to invade the underlying bone yielding nonspecific clinical presentation resembling fungal/bacterial infections or osteomyelitis. Seven rare cases of gingival CC are reported with special emphasis on immunohistochemistry and special stains. Clinical and demographic profile were analysed and all cases were subjected to Ki-67 and p53 immunostaining and Ayoub-Shklar histochemical staining. For comparison, age and gender matched seven cases of conventional OSCC with bony involvement were recruited. IBM SPSS statistics software version 26 (IBM Analytics, Armonk, New York, U.S.) was used to analyse the data. All cases of CC lacked p53 expression in contrast to OSCC and demonstrated intermediate to high proliferation index in stroma also. The keratin staining and cytokeratin profile in OSCC and CC were also found to be statistically different. CC is a rare well differentiated variant of OSCC with different pathways involved in the pathogenesis. Local aggressive and invasive nature could be the result of unique interaction between epithelium and stromal elements. Oral health care provider must be familiar with this uncommon variant of OSCC.

HER2-neu Expression and Survival in Colorectal Cancer in the South of Egypt; Immunohistochemistry and Genetic Study.

BACKGROUND: Colorectal cancer (CRC) is a major public health problem and one of leading cancer related death all over the world. One of the prognostic parameters that play a role in different types of cancer is HER2. However, the role of HER2 in CRC and its relation with clinicopathological features and survival is conflicting. We hypothesize that HER2 has different patterns of expression in CRC which may affect the prognosis of patients. MATERIAL & METHODS: We studied sixty specimens of colorectal carcinoma for HER2 immunohistochemistry and gene amplification and correlate it with clinicopathological features and patients` survival. RESULTS: Our data showed that negative HER2 expression was statistically associated with female gender (P = 0.010) and low & intermediate tumor budding (P = 0.030). There was a statistically significant relation between HER2 IHC and HER2 FISH amplification (P=0.000). Although neither HER2 immunoexpression and FISH amplification showed significant relation with overall survival nor disease free survival, HER2 amplified CRCs tended to have a worse survival compared with negative CRCs (40 months versus 50 months). The presence of male gender, lymphovascular invasion, nodal metastasis and distant metastasis (P = 0.013, 0.006, 0.006 and 0.000 respectively) were significantly statistically associated with poor overall survival. The presence of tumor grade III and high tumor budding (P = 0.035 and 0.007 respectively) were significantly statistically associated with shorter disease free survival. CONCLUSIONS: Our results showed that HER2 IHC 3+ staining is highly predictive of HER2 gene amplification in colorectal carcinomas. There is a tendency towards poorer prognosis in amplified HER2 CRC cases.

Significance of concurrent evaluation of HER2 gene amplification and p53 and Ki67 expression in gastric cancer tissues.

OBJECTIVE: The primary objective of this study is to explore the significance of concurrent evaluation of HER2 gene amplification and p53 and Ki67 expression in gastric cancer tissues. METHODS: Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) methodologies were used to detect HER2 gene amplification, as well as the expression levels of HER2, p53, and Ki67 proteins, across a group of 78 gastric cancer cases. RESULTS: The expression rate of the HER2 protein was determined to be 43.6% (34/78), with 17.9% (14/78) categorized as HER2 protein 3 + , 14.1% (11/78) as HER2 protein 2 + , and 11.5% (9/78) as HER2 protein 1 + . Using FISH technology, the HER2 gene amplification rate was identified as 19.2% (15/78), including 3 cases of HER2 gene cluster amplification, 5 cases of large granular amplification, 4 cases of punctate amplification, and 3 cases of high polysomy. The positive rate of p53 in gastric cancer cells was 52.6% (41/78), with 62.8% (49/78) of patients exhibiting a ki67 proliferation index ≤ 30, and 37.2% (29/78) accounting for a ki67 proliferation index > 30. The expression rates of the HER2 gene, p53, and ki67 in gastric cancer tissues were significantly associated with both gastric cancer staging and lymph node metastasis (P < 0.05). CONCLUSION: The HER2 gene amplification rate and gene copy number exhibit a positive correlation with the expression rates of p53 and ki67. Combining these assessments can provide crucial insights into the assessment of metastatic potential, disease progression, and prognosis of gastric tumor cells. This holds paramount importance in steering the formulation of individualized treatment strategies.

Immunohistochemical Profile of Triple-Negative Breast Cancers: SOX10 and AR Dual Negative Tumors Have Worse Outcomes.

Triple-negative breast cancer (TNBC) refers to an estrogen receptor-negative, progesterone receptor-negative, and HER2-negative breast cancer. Although accepted as a clinically valid category, TNBCs are heterogeneous at the histologic, immunohistochemical, and molecular levels. Gene expression profiling studies have molecularly classified TNBCs into multiple groups, but the prognostic significance is unclear except for a relatively good prognosis for the luminal androgen receptor subtype. Immunohistochemistry (IHC) has been used as a surrogate for basal and luminal subtypes within TNBC, but prognostication of TNBC using IHC is not routinely performed. We aimed to study immunophenotypic correlations in a well-annotated cohort of consecutive TNBCs, excluding postneoadjuvant chemotherapy cases. Tissue microarrays were constructed from a total of 245 TNBC cases. IHC stains were performed and consisted of luminal (AR and INPP4B), basal (SOX10, nestin, CK5, and EGFR), and diagnostic (GCDFP15, mammaglobin, GATA3, and TRPS1) markers. Survival analysis was performed to assess the significance of clinical-pathologic variables including age, histology, grade, lymphovascular invasion, Nottingham prognostic index category, American Joint Committee on Cancer (AJCC) stage, stromal tumor-infiltrating lymphocytes at 10% increment, CD8+ T-cell count, Ki-67 index, PD-L1 status, and chemotherapy along with the results of IHC markers. Apocrine tumors show prominent reactivity for luminal markers and GCDFP15, whereas no special-type carcinomas are often positive for basal markers. TRPS1 is a sensitive marker of breast carcinoma but shows low or no expression in apocrine tumors. High AJCC stage, lack of chemotherapy, and dual SOX10/AR negativity are associated with worse outcomes on both univariable and multivariable analyses. Lymphovascular invasion and higher Nottingham prognostic index category were associated with worse outcomes on univariable but not multivariable analysis. The staining for IHC markers varies based on tumor histology, which may be considered in determining breast origin. Notably, we report that SOX10/AR dual negative status in TNBC is associated with a worse prognosis along with AJCC stage and chemotherapy status.