Immunohistochemical Analysis Research Articles

LMNA::NTRK1 and PRDX1::NTRK1 Atypical Spitz Tumor: A Report of Two Additional Cases With Histological, Immunohistochemical, and Molecular Insights.

Over the past decade, advancements in molecular biology have contributed to changes in the diagnostic classification of Spitz neoplasms, including Spitz nevi, atypical Spitz tumors, and Spitz melanomas. The recent World Health Organization classification of skin tumors identifies fusion kinases, including NTRK1, NTRK2, and NTRK3, as critical drivers of these lesions. New fusion genes have continued to expand the spectrum of known molecular alterations, particularly within the category of Spitz NTRK-rearranged lesions. We present 2 new cases of NTRK-rearranged Spitz lesions: an atypical Spitz tumor with common LMNA::NTRK1 fusion and an atypical Spitz tumor with a rare PRDX1::NTRK1 fusion. Clinical, histopathological, immunohistochemical, and molecular analyses were performed to diagnose these patients. This report adds to the growing body of knowledge on NTRK-rearranged Spitz lesions and underscores the importance of integrating molecular findings with morphological and immunohistochemical data for the accurate classification and understanding of these neoplasms.

ALK-Positive Histiocytosis and its Distinctive Manifestation in the Breast

Abstract Introduction/Objective ALK-positive histiocytosis (APH) is a rare histiocytic proliferation disease that harbors ALK rearrangements, often involving fusion with KIF5B. Primary cases in the unilateral breast are exceptionally uncommon, with only a few reported cases globally, characterizing it as a unique histiocytic proliferation disorder. Methods/Case Report In our study, we report a case of unilateral multifocal breast involvement of ALK-positive histiocytosis following bilateral breast core biopsies in a 56-year-old Hispanic woman who presented with bilateral breast masses. Right breast imaging demonstrated multiple nodular densities, further characterized on ultrasound as a hypoechoic region of 8 cm with increased vascularity. On right breast biopsy, prominent proliferation of histiocytes (lacking high-grade cytologic atypia) with chronic inflammation, few giant cells, and focal cholesterol clefts were identified. On immunohistochemical studies, the lesional cells were variably positive for histiocytic markers CD68, CD163, and PU.1 and were negative for S100 and pancytokeratin. ALK1 showed multifocal staining in the lesional cells as confirmed on repeat study; however, ALK (D5F3), GMS and acid fast studies were negative. The presence of focal cholesterol clefts, scattered giant cells, and chronic inflammation lead us to consider aberrant ALK expression in a reactive process. However, APH was definitively diagnosed through confirmation of clonal histiocyte proliferation, observed findings on morphology, immunophenotyping, and the presence of KIF5B-ALK gene fusion as detected by comprehensive solid tumor fusion panel testing. Results (if a Case Study enter NA) NA Conclusion It is noteworthy that ALK-positive histiocytosis can occasionally present alongside features of a reactive process in the breast. Therefore, considering any history of prior surgery or trauma at the lesion site is crucial. However, we recommend a comprehensive approach in most cases, which includes morphological, immunohistochemical, and molecular analysis on all suspected histiocytosis cases. This approach aims to increase awareness and detection of this rarely described entity and to precisely distinguish it from other diseases for prognostic and therapeutic purposes.

Phosphatidylserine Topically Attenuates Imiquimod-induced Psoriasis Through Inflammation Inhibition in Mice.

Psoriasis is a chronic skin condition that is associated with persistent inflammation and skin lesions. Topical therapy has been a promising approach to the alleviation of psoriasis through the application of anti-inflammatory agents. Phosphatidylserine (PS) administration has shown anti-inflammatory effects in the trials. Consequently, the objective of this study was to evaluate the effects of topical PS on the potential improvement of an imiquimod (IMQ)-induced psoriasis model. Additionally, cyclosporine A was utilized as a comparative anti-psoriatic agent in our study. The psoriasis model was established by topically applying IMQ to the dorsal skin of mice once daily for five consecutive days. The efficacy of topical PS was assessed using the Psoriasis Area and Severity Index (PASI) score to evaluate skin lesions. Subsequently, the skin samples were analyzed using Baker's scoring system, Masson's trichrome staining, immunohistochemistry, and real-time PCR analysis. IMQ-induced plaque-type psoriasis resulted in a significant increase (P<0.05) in dermal thickness, hyperkeratosis, PASI score, and inflammatory cytokines at the lesion site. The topical PS and cyclosporine A significantly (P<0.05) reduced PASI score and dermal thickness, while also alleviating erythema and scaling when compared to untreated mice. Furthermore, biomolecular assessments revealed that PS significantly (P<0.05) inhibited the gene expression of IL-17, IL-23, and TNF-α cytokines in the IMQ-induced lesions. Topical PS may pointedly alleviate psoriasis through the inhibition of inflammation. The beneficial effects of the PS recommend further investigation in both experimental and clinical studies in the control of skin psoriasis.

Rare Presentation of Extraskeletal Osteosarcoma Mimicking Phyllodes Tumor

Abstract Introduction/Objective A 57-year-old female presented with a palpable mass in the left breast, measuring up to 9 cm by ultrasound. core needle biopsy identified an atypical spindle cell lesion. The differential diagnosis included a metaplastic carcinoma, borderline phyllodes tumor, malignant phyllodes tumor with potential sarcomatous transformation. Methods/Case Report Histological examination of the tumor was performed, and immunohistochemical stains were conducted to characterize the lesion. Further consultation with a specialized pathologist at the University of Michigan was sought to confirm the diagnosis. Molecular analysis was performed to assess for specific genetic alterations and expression patterns. The histological examination revealed a proliferation of atypical spindle cells forming a fascicular and storiform pattern, with numerous large, pleomorphic, multinucleated tumor cells and a high mitotic rate. Immunohistochemical stains showed strong positivity for CD10 and vimentin, with focal weak expression for desmin, and negativity for a broad panel of cytokeratins and other markers. Consultation with Dr. Abbott at the University of Michigan supported the diagnosis of extraskeletal osteosarcoma. Molecular analysis revealed PD-L1 expression and absence of NTRK gene fusions. FISH analysis showed suggestive alterations including loss of BRAF gene, loss of MYC, and suggestive gains or polysomy of PTEN gene. Results (if a Case Study enter NA) NA Conclusion The case represents a rare presentation of extraskeletal osteosarcoma in the breast, with distinctive histological and immunohistochemical features. The comprehensive workup including histology, immunohistochemistry, and molecular analysis aids in accurate diagnosis and potential therapeutic implications. Further research may elucidate the underlying mechanisms and treatment options for this uncommon malignancy.

Report of 3 Cases Diagnosed with Basal Cell Carcinoma and Systemic Mastocytosis with Favorable Prognosis

Abstract Introduction/Objective The co-existence of basal cell carcinoma (BCC) and systemic mastocytosis is an exceptionally rare clinical occurrence, and the prognosis is not well-documented. Understanding the clinical and histopathological features of this uncommon association is relevant for accurate diagnosis, management, and prognostication. Methods/Case Report We conducted a retrospective analysis of three cases of BCC with concurrent systemic mastocytosis that were identified in the pathology database of the University of Pennsylvania from 2010 to 2023. Patient demographics, clinical and histopathologic characteristics, and treatment outcomes were reviewed. Histopathologic assessment, immunohistochemistry, and C-KIT D816V mutation analysis (with an allele-specific PCR assay) were performed on biopsy material. Next-Generation Sequencing (NGS) was used to identify other hematologic neoplasm-associated mutations. Results (if a Case Study enter NA) All three cases were female with a median age of 55.3 years (50, 69, 47). In all three cases, atypical CD117+ tryptase+ CD25+ mast cells with mild to moderate pleomorphism were found in the dermis adjacent to the BCC cells. All three cases had bone marrow involvement. Serum tryptase levels were mildly elevated in all 3 patients (maximum 65.5 μg/L). All three cases harbor a C-KIT D816V mutation and a history of systemic glucocorticosteroids before the diagnosis of BCC. One of the cases was treated with phototherapy. NGS detected the following somatic mutations: Case #2 DNMT3A p.R882H c.2645G&amp;gt;A; Case #3 JAK2 V617F. Case #1 had multiple relapses of BCC, but a subsequent marrow biopsy did not identify any involvement by mastocytosis. Case #2 had mast cell leukemia, which typically has a poor prognosis; however, this patient has survived for several years. Case #3 had essential thrombocythemia and systemic mastocytosis with an associated hematological neoplasm, and her symptoms were stable. Treatment modalities for the three patients ranged from surgical excision to anti-mastocytosis therapy, with favorable outcomes (Table 1). Conclusion The coexistence of BCC with mastocytosis poses diagnostic challenges due to its infrequency and varied clinical presentations. Previous literature reports on treatments of mastocytosis such as phototherapy and steroids, which have been identified as risk factors for the development of basal cell carcinoma. However, recognizing this unique combination in clinical practice may aid in providing appropriate treatment strategies, ultimately leading to favorable patient outcomes.

Isolated Perianal Langerhans Cell Histiocytosis in a Human Immunodeficiency Virus-Positive Adult: A Rare Incidental finding

Abstract Introduction/Objective Langerhans cell histiocytosis (LCH) is a rare disorder characterized by abnormal proliferation of antigen-presenting cells, primarily Langerhans cells. Although it commonly affects bones, skin, and lungs, involvement of the gastrointestinal tract is rare. Specifically, isolated perianal LCH is exceptionally uncommon, with only a few documented cases reported in the literature. Here, we report a case of incidental perianal LCH in an adult HIV patient, highlighting the exceptional rarity and clinical importance of this occurrence. Methods/Case Report A 56-year-old Caucasian male with HIV underwent surgical resection of a 0.5 x 0.4 x 0.3 cm verrucous lesion on the posterior anal margin. His past medical history included granulomatous lymphadenitis, penile warts, and anal dysplasia. Microscopic examination of the excised tissue revealed Langerhans cells with characteristic features, including abundant eosinophilic cytoplasm and irregular nuclear membranes (resembling “coffee-bean” or “folded paper” appearance). Immunohistochemical analysis confirmed the diagnosis by demonstrating positivity for CD1a, S100, and CD68. The BRAF mutation was evaluated on the same paraffin-embedded block, which revealed the lack of the mutant BRAF V600E. PET-CT imaging showed no evidence of metastatic disease, emphasizing the isolated nature of the perianal LCH in this patient. Results (if a Case Study enter NA) NA Conclusion This case highlights the significance of recognizing and thoroughly evaluating rare and incidental conditions such as LCH in HIV patients. Our findings emphasize the importance of maintaining a high index of suspicion for LCH among healthcare providers and ensuring proper follow-up to rule out systemic involvement. Furthermore, there is a need for future studies to investigate the correlation between LCH and HIV. Given its rarity and diverse clinical presentation in immunocompromised individuals, a multidisciplinary approach, tailored treatment plans, and long-term surveillance with imaging modalities like PET/CT are essential for effectively managing adult-onset isolated LCH.

De-Differentiated Metastatic Melanoma: A Diagnostic Challenge

Abstract Introduction/Objective Melanoma is one of the common malignant neoplasms with several histological appearances. Its diagnosis is usually based on histomorphologic findings and immunohistochemistry (IHC). De-differentiated melanoma (DM) is a special form of malignant melanoma with different histo-morphologic and immunohistochemical characteristics than conventional malignant melanomas. It has a worse prognosis and can impose a diagnostic challenge. Methods/Case Report A 62-year-old male previously had melanoma on his chest, which was surgically removed with negative margins and no involvement of nearby sentinel lymph nodes. The patient presented two months later with a rapidly enlarging mass in the right axillary region. Subsequent lymph node dissection revealed several nodes, the largest measuring 14 cm with extensive necrosis. Microscopic examination of the largest mass revealed clusters of irregularly shaped cells displaying marked nuclear abnormalities, prominent nucleoli, and heightened mitotic activity. Immunohistochemical analysis of this mass showed negative results for SOX-10, HMB45, Melan-A, S100 protein, CAM5.2, BRAF, and myogenin. Conversely, the remaining lymph nodes exhibited typical signs of melanoma metastasis, expressing relevant melanoma markers. Given the patient’s history of melanoma and the presence of metastatic melanoma in nearby lymph nodes, the histological and immunohistochemical findings support the diagnosis of dedifferentiated cutaneous metastatic melanoma. Results (if a Case Study enter NA) N/A Conclusion The distinctive appearance and lack of typical markers in this type of melanoma pose considerable difficulties in distinguishing it from other malignancies like poorly differentiated carcinomas and high-grade sarcomas. Furthermore, dedifferentiated melanoma tends to be highly aggressive, often resisting standard and immunological treatments. Therefore, comprehensive clinical and histomorphological assessments are crucial for accurately diagnosing these complex and challenging cases.

Comparative Study of GPT-4Vision and Convolutional Neural Networks in Histopathological Image Analysis

Abstract Introduction/Objective Recent advancements in artificial intelligence (AI), particularly with Large Language Models like ChatGPT-4Vision (GPT-4V), have expanded the potential for automated interpretation of medical images. This study evaluates the diagnostic accuracy of GPT-4V in histopathological analysis of neurodegenerative diseases and compares its performance with traditional Convolutional Neural Networks (CNNs). Methods/Case Report We utilized 1515 histopathological images, including hematoxylin and eosin (H&amp;E) staining and tau immunohistochemistry, from patients with various neurodegenerative diseases, such as Alzheimer’s disease, progressive supranuclear palsy, and corticobasal degeneration. GPT-4V’s performance was assessed through multi- step prompts to assess how textual context influences the image interpretation. In the quantitative analysis, the diagnostic accuracy of GPT-4V and the CNN-based model YOLOv8 was assessed for classifying three tau lesions—astrocytic plaques, neuritic plaques, and tufted astrocytes. The analysis used both zero-shot and few-shot learning methods, where GPT-4V and YOLOv8 were evaluated on their ability to distinguish these lesions using ten hold-out test images and 490 training images per lesion. Results (if a Case Study enter NA) GPT-4V accurately recognized Lewy bodies in all cases, but it showed limited accuracy in identifying neurofibrillary tangles (20%) and Pick bodies (0%) on H&amp;E slides. Notably, GPT-4V often suggested Alzheimer’s disease as a potential diagnosis, relying more on contextual clues, such as the prevalence of certain diseases, rather than direct image analysis. In the tau immunohistochemical analysis, GPT-4V’s diagnoses were strongly influenced by additional information about staining and brain region. However, few-shot learning markedly improved GPT-4V’s diagnostic capabilities from 40% accuracy with zero-shot learning to 90% with few-shot learning, reaching best accuracy with 20-shot learning. This performance compared favorably against YOLOv8, which also achieved 90% accuracy but required 100-shot learning. Conclusion While GPT-4V faces challenges in independently interpreting histopathological images, few-shot learning significantly improves its accuracy. This approach is particularly promising for neuropathology, where acquiring extensive labeled datasets is challenging. The findings highlight the need for ongoing refinement of AI applications in pathology, emphasizing balanced integration of textual and visual data to optimize diagnostic efficacy and reliability.

Gastric and Gastrointestinal-like Immunophenotypes In Conventional Endometrial Endometrioid Adenocarcinomas Including Endometrioid Adenocarcinomas with Mucinous Differentiation: Frequency and Diagnostic Implications

Abstract Introduction/Objective Mucinous carcinomas of the gastric/gastrointestinal type (MCG) are now recognized as a rare, clinically aggressive subtype of endometrial cancer [EMCa]. However, neither their full morphologic spectrum, nor their defining immunophenotype, has been clearly defined. Previous proposals for their recognition include at least focal immunohistochemical expression of gastrointestinal markers, minimality or absence of ER and possibly PAX8 expression, and the absence of an endometrioid carcinoma component. Herein, we assess the frequency of gastric and gastrointestinal immunophenotypes in conventional endometrioid carcinomas without any discernible gastric/gastrointestinal-type morphology. Methods/Case Report Immunohistochemical analyses for CK7, CK20, CDX2, ER, SATB2, MUC6, PAX8 were performed on 81 EMCa, comprised of consecutively archived cases of low grade endometrioid carcinoma (n=47), FIGO grade III endometrioid carcinoma (n=12), and endometrioid carcinomas with mucinous differentiation (n=22). None showed goblet cells or gastric-type morphology. Expression levels were quantified as H-scores on a standardized 0-300 scale. Results (if a Case Study enter NA) Significant subsets of all 3 groups showed expression of MUC6, CDX2, SATB2 and CK20, without any significant differences between the groups. 56%, 62%, 23% and 25% of cases expressed MUC6, CDX2, CK20 and SATB2 respectively. 37% co-expressed MUC6 and CDX2, 12% co-expressed CDX2 and CK20, 6% co-expressed MUC6, CDX2 and CK20 and 2.5% co-expressed CDX2, CK20 and SATB2. The expression levels were generally low across all groups, with average H scores for positive cases being 49.5 [range 1-250] for MUC6, 33.7 [range 1-285] for CDX2, 24.0 [range 1-270] for CK20, and 30.5 [range; 2-220] for SATB2. There was no statistically significant correlation between the expression of any of the 4 markers (CK20, CDX2, SATB2 or MUC6) and low ER or PAX8 expression. However, the only 2 cases with high CDX2 expression (H: &amp;gt;/=200) were also associated with low ER (H&amp;lt;50) expression, and one of these concurrently showed high CK20 (H: 270) and low PAX8 (H: 2) expression, suggestive of true intestinal differentiation. Conclusion MUC6, SATB2, CDX2, and CK20 are not uncommonly expressed at low levels in endometrioid carcinoma. As such, the expression of these markers cannot be the sole basis for defining the clinically aggressive EMCa with true gastric/gastrointestinal differentiation, and for distinguishing them from conventional endometrioid carcinomas.

Dysgerminomas: germ cell tumors exhibit high expression of PD-L1 and associated with high TILs and good prognosis

Ovarian germ cell tumors (OVGCTs) account for 28% of all diagnosed ovarian cancers, and malignant germ cell tumors specifically account for approximately 13% of diagnosed ovarian cancers in Saudi Arabia. Although most germ cell tumor patients have a high survival rate, patients who experience tumor recurrence have a poor prognosis and present with more aggressive and chemoresistant tumors. The use of immunotherapeutic agents such as PD-L1/PD-1 inhibitors for OVGCTs remains very limited because few studies have described the immunological characteristics of these tumors. This study is the first to investigate PD-L1 expression in ovarian germ cell tumors and explore the role of PD-L1 expression in tumor microenvironment cells and genetic alterations. A total of 34 ovarian germ cell tumors were collected from pathology archives. The collected tumor tissues included ten dysgerminomas, five yolk sac tumors, five immature teratomas, and one mature teratoma, and the remaining samples were mixed germ cell tumors. The tumors were analyzed using immunohistochemical analysis to determine PD-L1 expression, immune cell infiltration and cancer stem cell populations and their correlation with clinical outcome. Furthermore, the genetic alterations in different subtypes of germ cell tumors were correlated with PD-L1 expression and clinical outcome. Datasets for testicular germ cells (TGCTs) were retrieved from The Cancer Genome Atlas (TCGA) and analyzed using cBioPortal (cbioportal.org) and Gene Expression Profiling Interactive Analysis (GEPIA). Compared with yolk sac tumors, dysgerminomas highly express PD-L1 and are associated with high levels of tumor infiltrating lymphocytes (TILs) and stem cell markers. In addition, compared with PD-L1-negative yolk sac tissue, dysgerminomas/seminomas with high PD-L1 expression are associated with more genetic alterations and a better prognosis. Our findings will contribute to the knowledge about the potential benefits of ovarian cancer immunotherapy in specific subsets of germ cell tumor patients and the risk factors for resistance mediated by tumor microenvironment cells.

Atypical Gastric Glomus Tumor of Uncertain Malignant Potential in A 16-Year-Old Female; A Rare Entity with Unique Findings

Abstract Introduction/Objective Gastric glomus tumor (GGT) is a rare mesenchymal tumor that is challenging to diagnose, especially when the immunoprofile overlaps with other more common gastric mesenchymal tumors. The majority of GGT are benign, however, rarely it can be atypical or even malignant. Herein, we present a case of a young female with atypical gastric glomus tumor of uncertain malignant potential. Methods/Case Report A 16-year-old female presented to the emergency with abdominal pain, coffee ground emesis, and melena. Imaging showed a 3.2 cm well-defined gastric mass arising from the muscularis propria. Results (if a Case Study enter NA) The FNA biopsy revealed clusters of tumor cells with uniform characteristics, exhibiting distinct cell membranes and eosinophilic to clear cytoplasm, surrounding prominent vasculature. Immunohistochemical analysis showed that the tumor cells were positive for SMA, synaptophysin, vimentin, calponin, and caldesmon, with weak, patchy positivity for DOG1. CD34 highlighted the vessels separating the tumor cellular clusters into lobules. CD117 and Desmin were negative. The Ki67 proliferation index varied with hotspot foci 25-30%. Morphology and immunoprofile suggest glomus tumor, however, neuroendocrine tumor and epithelioid GIST needed to be excluded. Subsequent resection specimen showed that the tumor was located within the muscularis propria with extension into the serosal vessels, suggesting vascular invasion, along with foci of cellular spindling and nuclear irregularity are identified. No necrosis noted. Tumor cells were positive for cyclin D1 while negative for myogenin, chromogranin, and DOG1. Overall, findings were consistent with GGT of uncertain malignant potential. Conclusion Although GGT are rare, they should be considered in the differential diagnosis of gastric mesenchymal tumors. The presence of diffuse SMA staining can help distinguishing them from GIST. It is crucial to scrutinize for signs of cellular and nuclear atypia, particularly in deeply seated glomus tumors.

A Diagnostic Challenge in the Biopsy of a Mammographic Abnormality

Abstract Introduction/Objective Primary breast marginal zone lymphoma (MZL) is an uncommon subtype of extranodal lymphoma, and its diagnosis presents challenges, particularly in distinguishing it from lymphoplasmacytic lymphoma (LPL). MYD88 L265P mutation has been identified in a subset of marginal zone lymphomas, comprising 6-9% of cases. This genetic alteration further complicates the differentiation between MZL and LPL in breast tumors. We present a case highlighting the diagnostic complexities associated with primary breast MZL. Methods/Case Report A 71-year-old female patient underwent mammographic screening, which revealed a suspicious lesion in her left breast. Subsequent PET scan showed a hypermetabolic area consistent with a primary breast lesion. Biopsy histology exhibited a diffuse atypical lymphoid infiltration with varying proportions of neoplastic lymphocytes. Immunohistochemical analysis revealed positivity for CD20, PAX5, BCL2, CD138, MUM1, and negativity for CD3, CD5, Cyclin D1, CD10, CD23, CD34, BCL6, TDT, CD30, GATA3, and CK AE1/3. Additionally, there was lambda light chain restriction, and the Ki67 proliferation rate index was approximately 50%. Fish analysis indicated abnormal BCL6 gene rearrangement. Molecular genetic testing confirmed the presence of MYD88 mutation with c.794T&amp;gt;C p.L265P. Notably, bone marrow biopsy showed no abnormalities, with normal hematopoiesis. Serum electrophoresis and immunofixation detected an IgM monoclonal protein with lambda light chain specificity. Results (if a Case Study enter NA) NA Conclusion The diagnosis of primary breast MZL was favored over LPL due to the absence of common LPL- associated symptoms such as bone marrow involvement. However, the distinction between these entities remains challenging, underscoring the importance of comprehensive diagnostic approaches integrating histopathology, immunohistochemistry, and molecular genetics. Further research is warranted to enhance diagnostic certainty in such cases, particularly as the management of MZL and LPL becomes increasingly specific with the advent of novel therapeutic agents and ongoing clinical trials.

Somatostatin receptor 2A expression in von Hippel-Lindau-related hemangioblastomas.

Central nervous system hemangioblastomas are the most prevalent manifestation of von Hippel-Lindau (VHL) disease and remain the main cause of mortality. Surgical resection is the primary treatment strategy, but is not always possible, and should be used as restrictively as possible. There is an unmet need for less invasive treatment strategies, such as targeted therapy. Expression of somatostatin receptor 2A (SSTR2A) in VHL-related hemangioblastomas has been described earlier, but the extent of expression in a larger population has yet to be determined. The authors hypothesize that a substantial subset of VHL-related hemangioblastomas show SSTR2A expression, which may serve as a potential new treatment target. Patients who were surgically treated for a VHL-related hemangioblastoma from 1990 until 2021 at the UMC Utrecht were included. Clinical data was derived from a clinical database. Tissue samples were histopathologically examined with use of hematoxylin and eosin staining, and immunohistochemical analysis of SSTR2A expression was performed. Forty-three tissue samples were obtained from 26 patients. Nine showed strong positivity for SSTR2A expression, whereas 13 showed moderate and 15 sparse expression. Three samples showed no expression of SSTR2A. The distribution showed right-skewedness favoring a strong expression. SSTR2A expression colocalized with endothelial markers and not with stromal cells. Additionally, within-patient variability for SSTR2A expression was described in 14 patients. SSTR2A is expressed in varying degrees in the majority of VHL-related hemangioblastomas. Future treatment with somatostatin analogues or even peptide receptor radionuclide treatment may be considered for SSTR2A-positive cases.

LONG-TERM SURVIVAL OF TANYCYTIC EPENDYMOMA OF LATERAL VENTRICLE WITH ADJACENT FRONTAL LOBE INVASION: CASE REPORT AND LITERATURE REVIEW

Abstract AIMS Tanycytic ependymoma (TE) of lateral ventricle is a rare variant of ependymoma often challenging to diagnose due to its distinctive histological features and similarity to other central nervous system neoplasms. This report presents a case of TE in a 48 years-old lady with 20 years of long-term survival and provides a comprehensive review of the literature to elucidate the clinical, radiological, and pathological characteristics of this entity. METHOD A 48-year-old woman presented with a left lateral ventricular tumor invading the left frontal lobe and pericallosal region, subsequently diagnosed as TE after stereotactic biopsy followed by radical radiotherapy. Epidemiological features, preoperative and postoperative radiological surveillance, and functional performance after adjuvant radiotherapy were reviewed. Additionally, we review the current literature to explore current perspective of TE. Three major medical database engines, PubMed (Medline), Scopus (ELSEVIER), and Cochrane were used to conduct a thorough literature search. RESULTS The patient exhibited notable neurological improvement following stereotactic biopsy and radical radiotherapy, with long-term surveillance demonstrating stability and reduction in tumor size over a 20-year period. Our literature review underscores the rarity of TE and its diagnostic challenges, emphasizing the importance of histopathological examination and immunohistochemical analysis for accurate diagnosis. TE exhibit unique ultrastructural features, requiring meticulous examination for proper classification. Additionally, we discuss the implications of TE’s histological resemblance to other intramedullary tumors and its potential impact on therapeutic decisions. CONCLUSION Tanycytic ependymomas pose diagnostic dilemmas due to their morphological overlap with other CNS tumors. However, heightened awareness among clinicians and pathologists is crucial for accurate identification and appropriate management. Further research into the molecular mechanisms underlying TE is warranted to enhance diagnostic precision and refine treatment strategies, ultimately improving patient outcomes.

A Rare Case of Diffuse Large B Cell Lymphoma Co-occurring with Small Lymphocytic Leukemia: De Novo Process or Richter’s Syndrome?

Abstract Introduction/Objective Diffuse large B-cell lymphoma (DLBCL) is the most prevalent subtype of lymphoma and can arise either de novo or through transformation from indolent lymphomas, such as Chronic Lymphocytic Leukemia (CLL), known as Richter syndrome (RS). DLBCL derived from RS tends to exhibit more aggressive behavior compared to de novo DLBCL. Methods/Case Report We present a case of a 57-year-old female with no significant medical history, who initially presented with antibiotic and prednisone-resistant sinusitis, progressing to bilateral neck pain and eye congestion. Computed tomography (CT) imaging revealed a 3 cm mass in the right nasal cavity extending to the right maxillary sinus and medial right orbit. Histopathological examination showed diffuse sheets of intermediate to large cells with irregular nuclear contours, dispersed chromatin, variably conspicuous nucleoli, and moderate cytoplasm. Additionally, scattered foci of monotonous, atypical lymphoid cells with lower grade morphology, including small size and condensed chromatin, were also present. Immunohistochemical analysis revealed differential staining patterns between the two cell populations. The larger atypical cells expressed CD20, PAX5, CD10, BCL-6, MUM1, BCL-2, MYC, CD19 (dim), and exhibited a high Ki-67 proliferation index (&amp;gt;80%). In contrast, the smaller atypical cells were positive for CD5, CD19, CD20, PAX5, BCL-2, and CD23 (subset), with a lower Ki-67 proliferation index (&amp;lt;5%). Flow cytometry analysis of tissue samples revealed two distinct clones: Surface Kappa-restricted CD19 dim B cells (38.9%) with CD5- CD10 dim CD20+ and surface Lambda-restricted CD19+ B cells (58.7%) with CD5+ CD10- CD20+. FISH analysis revealed no gene rearrangements. The final diagnosis was Diffuse large B-cell lymphoma, germinal center B- cell phenotype, with aggressive features and focal involvement by small lymphocytic lymphoma/chronic lymphocytic leukemia. Results (if a Case Study enter NA) NA Conclusion The relationship between the large B-cell lymphoma and SLL/CLL remains uncertain; however, given the different immunophenotype and light chain expression observed by flow cytometry, they are likely to represent separate processes.

Trypanosoma cruzi-derived exovesicles contribute to parasite infection, tissue damage, and apoptotic cell death during ex vivo infection of human placental explants.

Trypanosoma cruzi, the causative agent of Chagas disease, can be congenitally transmitted by crossing the placental barrier. This study investigates the role of T. cruzi-derived exovesicles (TcEVs) in facilitating parasite infection and the consequent tissue damage and apoptotic cell death in human placental explants (HPEs). Our findings demonstrate that TcEVs significantly enhance the parasite load and induce tissue damage in HPEs, both in the presence and absence of the parasite. Through histopathological and immunohistochemical analyses, we show that TcEVs alone can disrupt the placental barrier, affecting the basal membrane and villous stroma. The induction of apoptotic cell death is evidenced by DNA fragmentation, caspase 8 and 3, and p18 fragment immunodetection. This damage is exacerbated when TcEVs are combined with T. cruzi infection. These findings suggest that TcEVs play a critical role in the pathogenesis of congenital Chagas disease by disrupting the placental barrier and facilitating parasite transmission to the fetus. This study provides new insights into the mechanisms of transplacental transmission of T. cruzi and highlights the potential of targeting TcEVs as a therapeutic strategy against congenital Chagas disease.

Pyrazolone-nicotinic acid derivative (4Z)-4-(2-hydroxybenzylidine)-5-methyl-2-(pyridine-3-ylcarbonyl)-2, 4-dihydro-3H-pyrazole-3-one (IIc) as multitarget inhibitor of neurodegeneration and behavioural impairment in Dementia.

The study was aimed at the synthesis and pharmacological investigation of (4Z)-4-(2-hydroxybenzylidine)-5-methyl-2-(pyridine-3-ylcarbonyl)-2, 4-dihydro-3H-pyrazole-3-one (IIc) in mice model of scopolamine-induced neurodegeneration and cognition impairment. The behavioural studies included Y-Maze Test, Water Morris Test, and Novel Object Recognition Test in Albino mice (20-25g). Scopalamine was used as an inducing agent. The acetylcholinesterase (AChE) inhibitory assay was used to assess the role of the test compounds in vitro. The Crystal Violet Staining (Nissl staining) was used to assess the neuroprotective and antiapoptotic effect through quantifying the number of neurons and viability. The expression of the anti-inflammatory enzyme cyclooxygenase-2 (COX-2), cytokine tumour necrotic factor (TNF-α), key transcription factor producing pro-inflammatory signals nuclear factor kappa B (P-NFkB), and apoptosis marker p-JNK was validated through enzyme-linked immunosorbent assay (ELISA) and immunohistochemical (IHC) analysis. The tested compound reverted cognitive and behavioural impairment through inhibiting scopolamine-induced inflammation and oxidative stress. We found that the compound IIc improved the short-term memory and learning behaviour of the experimental animals. Further investigation into molecular mechanisms showed that this effect was the manifestation of immunomodulatory, antioxidant, and consequently, of downsizing of inflammatory cytokines. These results were further validated through docking analysis. Finally, we conclude that the pyrazolone-nicotinic acid derivative IIc reversed the scopolamine-induced cognitive and behavioural deficits, attributed to acetylcholinesterase inhibition, neuronal recovery, antioxidant potential, and through downregulating the neuroinflammatory mediators p-NF-kB, cytokine TNF-α, and anti-inflammatory enzyme COX-2.

Identification of novel biomarkers for atherosclerosis using single-cell RNA sequencing and machine learning.

Atherosclerosis (AS) is a predominant etiological factor in numerous cardiovascular diseases, with its associated complications such as myocardial infarction and stroke serving as major contributors to worldwide mortality rates. Here, we devised dependable AS-related biomarkers through the utilization of single-cell RNA sequencing, weighted co-expression network (WGCNA), and differential expression analysis. Furthermore, we employed various machine learning techniques (LASSO and SVM-RFE) to enhance the identification of AS biomarkers, subsequently validating them using the GEO dataset. Following this, CIBERSORT was employed to investigate the correlation between biomarkers and infiltrating immune cells. Consequently, 256 differentially expressed genes (DEGs) were selected in samples of AS and normal. GO and KEGG analyses indicated that these DEGs may be related to the negative regulation of leukocyte-mediated immunity, leukocyte cell-cell adhesion, and immune system processes. Notably, C1QC and COL1A1 were pinpointed as potential diagnostic markers for AS, a finding that was further validated in the GSE21545 dataset. Moreover, the area under the curve (AUC) values for these markers exceeded 0.8, underscoring their diagnostic utility. Analysis of immune cell infiltration revealed that the expression of C1QC was correlated with M0 macrophages, gamma delta T cells, activated mast cells and memory B cells. Similarly, COL1A1 expression was linked to M0 macrophages, memory B cells, activated mast cells, gamma delta T cells, and CD4 native T cells. Finally, these results were validated using mice and human samples through immunofluorescence, immunohistochemistry, and ELISA analysis. Overall, C1QC and COL1A1 would be potential biomarkers for AS diagnosis, and that would provides novel perspectives on the diagnosis and treatment of AS.

Unique Glycans in Synaptic Glycoproteins in Mouse Brain.

The synapse is an essential connection between neuronal cells in which the membrane and secreted glycoproteins regulate neurotransmission. The post-translational modifications of glycoproteins with carbohydrates, although essential for their functions as well as their specific localization, are not well understood. Oddly, whereas galactose addition to glycoproteins is required for neuronal functions, galactosylation is severely restricted for Asn-linked on N-glycans in the brain, and genetic evidence highlights the important roles of galactose in brain functions and development. To explore this novel glycosylation, we exploited an orthogonal technology in which a biotinylated sialic acid derivative (CMP-biotin-Sia) is transferred to terminally galactosylated proteins by a recombinant sialyltransferase (rST6Gal1). This approach allowed us to identify the carrier proteins as well as their localization on brain sections. Immunohistochemical analysis of the biotinylated glycoproteins in brain sections demonstrates that they are largely positioned in the pre- and postsynaptic membranes. Consistent with this positioning, glycoproteomic analyses of the labeled glycoproteins identified a number of them that are involved in synaptic function, cell adhesion, and extracellular matrix interactions. The discovery of these galactosylated N-glycoproteins and their relative confinement to synapses provide novel insights into the unusual and specific nature of protein glycosylation in the brain.

Prediction of homologous recombination deficiency identifies colorectal tumors sensitive to PARP inhibition

The synthetic lethal effect observed with the use of PARP inhibitors (PARPi) with tumors characterized by the loss of key players in the homologous recombination (HR) pathway, commonly referred to as “BRCAness”, is maintaining high interest in oncology. While BRCAness is a well-established feature in breast, ovarian, prostate, and pancreatic carcinomas, our recent findings indicate that up to 15% of colorectal cancers (CRC) also harbor defects in the HR pathway, presenting promising opportunities for innovative therapeutic strategies in CRC patients. We developed a new tool called HRDirect, which builds upon the HRDetect algorithm and is able to predict HR deficiency (HRD) from reference-free tumor samples. We validated HRDirect using matched breast cancer and CRC patient samples. Subsequently, we assessed its efficacy in predicting response to the PARP inhibitor olaparib by comparing it with two other commercial assays: AmoyDx HRD by Amoy Diagnostics and the TruSight Oncology 500 HRD (TSO500-HRD) panel by Illumina NGS technology. While all three approaches successfully identified the most PARPi-sensitive CRC models, HRDirect demonstrated superior precision in distinguishing resistant models compared to AmoyDX and TSO500-HRD, which exhibited overlapping scores between sensitive and resistant cells. Furthermore, we propose integrating HRDirect scoring with ATM and RAD51C immunohistochemical analysis as part of our “composite biomarker approach” to enhance the identification of HRD tumors, with an immediate translational and clinical impact for CRC personalized treatment.