Immunohistochemical Tests Research Articles

Multinucleated tumor cells and micropapillary morphology appear to be predictors of poor prognosis in renal cell carcinoma with papillary and oncocytic features.

Renal cell carcinoma with papillary and oncocytic features (RCC-PO) are poorly understood, partially due to conflicting results in multiple studies. The histological features that predict behavior of RCC-PO have not been elucidated. The aim is to review clinicopathologic features and to correlate clinical outcomes of patients with RCC-PO to further expand our knowledge on these heterogeneous tumors. An archival search was done for "RCC" and "papillary," and tumors with >50% papillary and oncocytic features were included. Clinicopathologic data including tumor size, grade, stage, molecular and immunohistochemical testing when performed, and follow-up data were collected. Using multivariate analyses, correlation between histological features, tumor stage and prognosis were analyzed. Sixty-one patients with RCC-PO were identified of which 49 (80%) were male with a median age of 65 (range: 36-93) years, and a mean tumor size of 5.2 (range: 1-21.5) cm. Micropapillary features were seen in 4, bizarre nuclei (at least 3 times larger or with irregular shape) in 6, multinucleated tumor cells (MTC) in 15, single or small clusters (SSC) (made of 2-3 tumor cells) located away from areas of necrosis in 16, and striking eosinophilic cytoplasmic inclusions in 3 tumors, respectively. Thirty-six (59%) tumors were high-grade (WHO/ISUP grade 3-4), and 23 (38%) had a high stage (≥pT3 or pN1). Tumors were positive for AMACR (15/16) and CK7 (13/17), with preserved FH (7/7) staining and were all negative for CD117 (0/7), ALK, TFE3, cathepsin K, Melan A, and HMB45 (0/4, each). Three tumors underwent chromosomal microarray (CMA) plus gene fusion assay, and FISH and germline testing for FLCN and MET gene alterations by PCR were done on 1 each. Ten (16%) patients had a local recurrence (LR) or metastasis after nephrectomy; 4 died of disease (2 had tumors with micropapillary features), with a median follow-up of 7 (range: 0.01-19) years. Tumors with micropapillary features showed significantly higher RCC-PO-related mortality (50% vs. 3.5%, p<0.001). In multivariable analysis, SSC correlated with a higher stage (HR: 11.95; p=0.005); micropapillary features (HR: 18.42; p=0.017) and MTC (HR: 180.22; p=0.036) with presence of metastasis/LR; and micropapillary features with a higher RCC-PO-related mortality (HR: 60.35; p=0.036). RCC-PO are cytogenetically heterogeneous with overlapping features of various renal neoplasms. Micropapillary features and MTC appear to be independent predictors of poor outcomes in these tumors.

Liver metastasized pancreatic neuroendocrine tumor in a 17-year-old female: A case report.

Pancreatic neuroendocrine tumors (PNETs) are rare and often misdiagnosed due to their vague symptoms and tumor heterogeneity. Early detection using computed tomography (CT) is essential, particularly in regions without access to advanced diagnostic tools like immunohistochemistry and genetic testing. Neuroendocrine tumors (NETs) are rare tumors in adults and extremely rare in the pediatric population, as pancreatic NETs (pNETs) have an incidence rate of <0.1 per million. We present a case of a 17-year-old female with a liver metastasized pNET. A 17-year-old female with a history of intermittent abdomen-back pain presented to the clinic with severe upper abdominal pain radiating to the shoulder. The routine tests were normal. An ultrasound showed multiple lesions in the liver, which were confirmed by a computed tomography (CT) that uncovered a pancreatic lesion too. A liver biopsy proved it was a metastasized pNET with positive NET markers on IMC staining. The metaiodobenzylguanidine (MIBG) scan flared the liver lesion. The patient was started on Octreotide long-acting release (LAR) 30 mg once monthly. The rarity of these tumors makes their diagnosis difficult, but they should not be omitted and must be considered when there are long-lasting symptoms that are not compatible with common illnesses. These tumors are curable in their early stages.

The challenge of diagnosing neuroendocrine neoplasms: experience from a national reference center.

Correctly diagnosing neuroendocrine neoplasm (NEN) has become increasingly challenging, given that more histomorphologic and immunophenotypic NEN mimics have been identified in recent years. A systemic review was conducted on the 4795 consult cases submitted with initial diagnoses of NEN to a national reference center in China from 2013 to 2021. Among them, 443 cases were misdiagnosed as epithelial NENs after reevaluation with the help of immunohistochemical and/or molecular tests, ranging from 7.1 to 13.2%, with yearly increases. The misdiagnoses varied among age groups and tumor sites. Exocrine carcinoma was the most common (63.2%), followed by mesenchymal tumors. Other common tumors that were misdiagnosed included hepatocellular carcinoma, salivary gland tumor, and gastrointestinal stromal tumor. Aberrant expression of neuroendocrine markers was frequent (218/408, 53.4%), with diffuse positivity ranging from 8.2 to 51.7% for synaptophysin, chromogranin A, and INSM1 stains in all non-NEN cases. Selecting appropriate immunohistochemical stains based on H&E morphology is the key to avoiding diagnostic pitfalls. Medical history and molecular genomic information greatly assist in correctly diagnosing NENs and their mimics.

Hsa_circ_0001492 regulates the hsa-miR-145-5p/ovarian carcinoma immunoreactive antigen domain 2 axis to promote the progression of lung adenocarcinoma.

Circular RNA (circRNA) has been proven to be a key regulator in a range of tumor illnesses, such as lung adenocarcinoma (LUAD); however, the regulatory mechanisms of circRNA remain unclear. In this study, circRNA (hsa_circ_0001492) in LUAD was examined for its regulatory and functional potential. qRT-PCR was used to assess the hsa_circ_0001492 level in LUAD. The RNAse R digestion test was employed to isolate hsa_circ_0001492. The primary location of hsa_circ_0001492 enrichment in LUAD cells was identified through a nucleoplasmic separation test. LUAD cell migration, proliferation, and spherogenicity were examined using wound healing, transwell, EdU, and cell spherogenicity assays. The association between miR-145-5p and hsa_circ_0001492/ovarian carcinoma immunoreactive antigen domain 2 (OCIAD2) was validated using a dual luciferase experiment. The interaction between sh-hsa_circ_0001492 and miR-145-5p was confirmed through an RNA pull-down assay. The effects of hsa_circ_0001492, miR-145-5p, and OCIAD2 on LUAD tumor development were examined using xenograft mouse models and immunohistochemistry tests. Results showed a higher amount of hsa_circ_0001492 in LUAD. The cytoplasm of LUAD cells was observed in the area where hsa_circ_0001492 mainly accumulated; hsa_circ_0001492 enhanced LUAD cell migration, proliferation, and sphere-forming ability. MiR-145-5p and OCIAD2 were identified as targets of hsa_circ_0001492 and miR-145-5p, respectively. The level of OCIAD2 was increased by hsa_circ_0001492 through targeted binding to miR-145-5p. In nude mice, tumor growth was inhibited by silencing hsa_circ_0001492, while knockdown of miR-145-5p and overexpression of OCIAD2 promoted the growth of LUAD tumors. In conclusion, hsa_circ_0001492 regulates the hsa-miR-145-5p/OCIAD2 axis to promote the progression of LUAD, and could be a useful target for the diagnosis and treatment of LUAD.

Staged operations of acquired lymphangiectasia of the vulva: 10 cases clinical analysis

Objective: To investigate the characteristics, diagnosis and therapeutic effect of acquired lymphangiectasia of the vulva (ALV). Methods: A retrospective analysis of clinicopathological and follow-up data was conducted on the patients treated in Capital Medical University Affiliated Beijing Shijitan Hospital due to female ALV from July 2009 to July 2023. The patients who completed the staged operations [partial labiectomy and reconstruction + thoracic ductplasty and (or) perineal lymphovenous anastomosis] were included in the study and followed up. The improvement of perineal swelling, blister range, fluid leakage volume and frequency were evaluated through outpatient visits by the symptom rating scale of ALV (hereinafter referred to as the symptom rating scale) before and after surgery. Results: A total of 48 patients were treated due to ALV from July 2009 to July 2023, of which 98% (47/48) were postoperative pelvic malignant tumors and 94% (45/48) had a history of radiotherapy. A total of 10 patients with ALV who completed the staged operations were included in this study. (1) Clinical characteristics and diagnosis: 10 patients had a median age of 60 years old (50, 63 years old ). The median duration from cervical cancer surgery and radiation therapy to vulvar swelling was 1.5 years (0.0, 2.0 years), and the median duration from vulvar swelling to blister formation and leakage was 0.0 years (0.0, 4.8 years). Seven patients (7/10) had a history of recurrent erysipelas; 7 patients (7/10) had the most severe symptom (widespread blisters, persistent fluid leakage, and large amount of fluid leakage); noncontrast magnetic resonance lymphography (NCMRL) showed edema signals in the perineal region of all the patients, and increase of agent in the perineal region was observed in lymphoscintigram (LS). (2) Surgical treatment and postoperative pathological examination: of the 10 ALV patients who completed staged surgical treatment, 6 cases (6/10) were diagnosed with thoracic duct outlet obstruction and underwent thoracic ductplasty and partial labiectomy and reconstruction. Perineal lymphovenous anastomosis and partial labiectomy and reconstruction were performed in 4 cases (4/10) without thoracic duct outlet obstruction. Postoperative routine pathological examination of 10 patients (10/10) showed dermal papilla lymphangiectasia. Immunohistochemical tests were performed on 5 patients, all of which were positive for D2-40 and negative for CD34. (3) Efficacy: 8 patients completed the postoperative follow-up, and the median follow-up time was 31.0 months (17.5, 78.3 months). The perineal swelling and the blister fluid leakage were all significantly improved after the staged operations. All indexes of the symptom rating scale, including the degree of perineal swelling, blister range, fluid leakage volume and frequency, were significantly improved in 8 follow-up patients, and 3 (3/8) of them were cured; the median symptom score decreased significantly from 11.0 before surgery to 3.0 after surgery (P<0.001). The incidence of erysipelas was significantly reduced from 7/10 before surgery to 2/8 after surgery (P=0.035). Conclusions: The main causes of female ALV are pelvic tumor surgery and radiotherapy. The clinical diagnosis is made from relevant medical history, clinical manifestations, LS and magnetic resonance imaging. The diagnosis is confirmed by histopathological findings. Pathological results show lymphangiectasia in the dermal papilla, and immunohistochemical staining show positive for D2-40 and negative for CD34. The effect of staged surgery on ALV is remarkable and even cured, and could effectively reduce the incidence of erysipelas.

Comparing the Sensitivity of HER2 Epitope Detection of HercepTest mAb pharmDx (Dako Omnis, GE001) and Ventana PATHWAY Anti-HER-2/neu (4B5) Using IHC Calibrators.

Accurate assessment of HER2 expression levels is paramount for determining eligibility for targeted therapies. HER2 immunohistochemistry provides a semiquantitative measurement of HER2 protein overexpression. Historically, little focus has been on the lower end of the HER2 expression range. The advent of novel therapeutic molecules that require fewer membrane epitopes to be effective has prompted a reevaluation of the current immunohistochemistry testing protocols, with special emphasis on the detection limit. Here, we have used Boston Cell Standards technology to determine the sensitivity of 2 commercially available HER2 immunohistochemistry assays, including a lower limit of detection.

Lynch syndrome diagnostic testing pathways in endometrial cancers: a nationwide English registry-based study

BackgroundFor female patients with Lynch syndrome (LS), endometrial cancer (EC) is often their first cancer diagnosis. A testing pathway of somatic tumour testing triage followed by germline mismatch repair (MMR)...

IL-17RA/CTSK axis mediates H. pylori-induced castration-resistant prostate cancer growth.

In this investigation, we explored the molecular dynamics guiding the progression of castration-resistant prostate cancer (CRPC) influenced by Helicobacter pylori (H. pylori)-mediated M2 polarization of macrophages through the IL-17RA/CTSK/EMT axis. An 830-patient clinical trial categorized subjects into hormone-sensitive prostate cancer (HSPC) and CRPC groups. H. pylori infection, evaluated by ELISA, exhibited a higher incidence in CRPC patients, impacting overall survival (OS) and progression-free survival. In-depth in vitro and in vivo experiments, including 16S rDNA sequencing, immunohistochemical tests, and transcriptome analysis, unveiled that H. pylori promotes CRPC growth and metastasis by upregulating IL-17RA and CTSK, leading to enhanced EMT. Notably, M2 macrophages emerged as pivotal immune cells influencing CRPC progression. This study uncovers a novel pathway wherein H. pylori enrichment exacerbates CRPC by inducing macrophage M2 polarization, IL-17RA/CTSK expression, and EMT activation, shedding light on a previously unrecognized mechanism contributing to the growth and metastasis of CRPC.

Molecular Tumor Testing on Colorectal Adenocarcinoma Specimens in a Large Community-Based Healthcare System.

This study aimed to describe the adherence of National Comprehensive Cancer Network guidelines to perform genetic screening for all colorectal cancer (CRC) specimens with molecular tumor testing, eg, immunohistochemical (IHC) testing, in a large community-based healthcare setting. The study also identified trends involving characteristics of CRC, individual reporting physician, and physician location and examined the potential impact of these trends on the performance of molecular tumor testing. This was a retrospective, multi-center study using a centralized pathology database to assess molecular testing on CRC specimens. The primary endpoint was whether tumor testing of a CRC specimen was performed. Secondary endpoints included tumor location within the colon (ie, the right or left side), year of CRC diagnosis, and location of the pathologist within the Advocate Aurora Health (AAH) system. The data were collected from 2016 to 2020. A total of 2469 CRC cases, reviewed by 47 pathologists practicing in five separate hospitals, were identified within the AAH system for the selected five-year time period. IHC testing was performed in 1666 of these specimens (67.5%). There was no statistical difference between CRC sidedness and IHC testing performed (p = 0.9). There were no discernible features or trends for the ordering of IHC testing among different pathologists. Molecular tumor testing for CRC specimens in this large community-based healthcare setting was inconsistent and below the ideal adherence rate of 100%. Secondary findings offered neither explanation nor trends in likelihood to send samples for IHC testing. Education would be beneficial for pathologists and all physicians who care for patients with CRC in community-based health care settings.

Diagnostic workup of triple hit lymphoma by fine needle aspiration

Abstract Introduction/Objective Triple-hit lymphomas (THL) represent a rare and aggressive subset of high-grade B-cell lymphomas characterized by a triad of translocations involving MYC, BCL2, and BCL6. Patients with THL face poor outcomes when treated with the standard diffuse large B-cell lymphoma protocol. Thus, intensified regimens have emerged as a frontline strategy for managing these patients. Therefore, accurate diagnosis and molecular subclassification of these lymphomas are essential for guiding therapeutic decisions for these patients. Here, we report a case study detailing the diagnostic assessment of THL utilizing limited diagnostic material obtained through palpation-guided fine-needle aspiration (FNA). Methods/Case Report A 58-year-old male presented with a rapidly enlarging neck mass, accompanied by worsening dysphagia, pain, and fatigue over the course of two months. Laboratory testing showed leukocytosis and imaging studies revealed a partially necrotic, 7.8 x 9.1 x 9.4 cm right jugular nodal mass. The patient was referred to otolaryngology for further evaluation, where FNA of the mass was performed by the cytopathology team. The aspirate was sent for cytology with cell block and flow cytometry. The Romanowsky stain revealed abundant, large, discohesive cells with prominent nucleoli and scant cytoplasm with an abundance of lymphoglandular bodies in the background. Immunohistochemistry (IHC) on the cell block demonstrated BCL-2, BCL-6, and MYC expression, and a Ki-67 proliferation index &amp;gt;95%. Concurrent flow cytometric analyses showed an aberrant B-cell population expressing CD19, CD20, CD22, CD23 and surface lambda light chain. Further fluorescence in situ hybridization (FISH) analysis performed on the cell block confirmed gene rearrangements in BCL2, BCL6 and MYC, thereby classifying this patient’s disease as THL. Results (if a Case Study enter NA) NA Conclusion Diagnosing THL typically demands sufficient tissue for histology, cytology, flow cytometry, IHC, and molecular testing. Herein, we showcase a notable example where the diagnostic evaluation of THL was accomplished using limited material obtained from FNA. This case highlights the efficacy of conducting comprehensive diagnostic studies even when tissue availability is constrained. Utilizing cytologic samples not only streamlines the diagnostic process but also minimizes the need for patients to undergo additional invasive procedures, thus potentially reducing delays in diagnosis and therapeutic intervention.

Diffuse meningeal melanocytosis – a silent culprit

Abstract Introduction/Objective Diffuse meningeal melanocytosis is a rare melanocytic proliferation that poses significant risk of severe hydrocephalus and mortality among children and young adults. Although the clonal melanocytes do not typically exhibit malignant morphological features, their capability for extensive invasion and malignant-like behavior necessitates tissue biopsy alongside immunohistochemical and molecular testing for definitive diagnosis. Methods/Case Report A 17-year-old male presented with progressive headaches, photophobia, and nausea, initially attributed to migraines. Neuro-opthalmological assessment revealed papilledema, leading to a diagnosis of idiopathic intracranial hypertension. Serial imaging showed fluctuating leptomeningeal enhancement and moderate communicating hydrocephalus without parenchymal lesions. Therapeutic lumbar punctures provided modest symptom improvement; increased opening pressure was observed. Evaluation of seven CSF specimens showed low glucose levels, increased cellularity consisting of bland appearing epithelioid cells of unknown etiology, and increased lymphocytes. Infectious causes were excluded. Due to the indeterminate CSF findings, discussion between the cytopathologist and neuro-opthamologist was crucial to facilitate tissue biopsy to exclude a neoplastic process. Subsequent shunt placement and cerebral cortex biopsy revealed neoplastic cells with sheet-like architecture coating the dura without overt brain invasion. The tumor cells had eosinophilic cytoplasm without pigment and enlarged nuclei with irregular contours, vesicular chromatin, and prominent nucleoli. No high-grade features were seen. Immunohistochemical stains were positive for MART1, HMB45, and PRAME, consistent with a melanocytic lesion. FISH melanoma panel was negative. The final diagnosis was diffuse meningeal melanocytic neoplasm, most consistent with meningeal melanocytosis. The patient received chemotherapy with improved symptoms and stable disease. Results (if a Case Study enter NA) NA Conclusion Diffuse meningeal melanocytosis is a challenging cytologic diagnosis as melanocytes can morphologically mimic lymphocytes and monocytes, and the low cellularity of CSF specimens often results in insufficient cell blocks for ancillary tests. The direct communication of the pathologist with the clinical team to correlate pathology, radiology, and clinical symptoms was essential to ensure the proper management of this patient.

Squamoid eccrine ductal carcinoma of the vulva: A case report

Abstract Introduction/Objective A 53-year-old female sought medical attention for left vulvar pain and a vulvar lesion. Methods/Case Report Physical examination revealed a 1.0 x 1.0 cm lesion within a background of lichen sclerosus. Biopsy demonstrated a carcinoma with tubular and glandular architecture, areas of squamoid differentiation and widespread perineural invasion. Ancillary immunohistochemistry testing with keratin 7 highlighted foci of ductal differentiation. Tumor cells were also positive for p53, p63, pankeratin, and keratin 5/6. The Ki-67 proliferation index was approximately 15%. Tumor cells were negative for Keratin 20, PAX 8, p16, and CD 34. We diagnosed the lesion as a vulvar sweat gland adenocarcinoma of the squamoid eccrine ductal subtype. Results (if a Case Study enter NA) N/A Conclusion Carcinomas of vulvar sweat gland origin are extremely rare, comprising less than 1% of all vulvar cancers. To the best of our knowledge, this is the first case report of squamoid eccrine ductal carcinoma afflicting the vulva.

Impact of a PD-L1 Learning Collaborative: outcomes from a mixed-methods evaluation

Abstract Introduction/Objective PD-L1 Immunohistochemistry testing is often required to determine eligibility for immune checkpoint inhibitor therapy. An ASCP PD-L1 Learning Collaborative (LC) was formed aiming to: 1) identify ways to streamline PD-L1 testing; 2) encourage members to locally implement changes; and 3) develop a resource guide for the community. Methods/Case Report The PD-L1 LC (n=38 pathologists and laboratory professionals) participated in 3 activities: 1) 4 meetings in which LC members discussed current literature and practice; 2) 3 30-minute on-demand, credit-bearing panel videos, in which selected LC members summarized the LC outputs and shared their experiences; and 3) a guide summarizing resources relevant to streamlining PD-L1 testing. The mixed-methods evaluation included: 1) five- minute surveys before (n=24), immediately after (n=11) and 7-months post-LC (n=17); 2) polling questions (2-4 per meeting); 3) semi-structured interviews (n=5). Quantitative data was analysed using descriptive and inferential analysis, qualitative data using a thematic analysis / inductive reasoning approach. Results (if a Case Study enter NA) Baseline data confirmed delays in testing caused by unstandardized PD-L1 testing processes and suboptimal confidence in PD-L1 validation and methodologies. Post-LC, members self-reported perceived increased knowledge and higher confidence levels regarding discussion of PD-L1 scientific evidence and best practices. At the 7-month follow-up, 59% of respondents reported at least one PD-L1-related practice change, with 29% of participants selecting:1) Improving protocols for specimen acquisition, handling, or processing; 2) Improving communication with multidisciplinary care team; 3) Optimizing biomarker testing workflows. Remaining suboptimal knowledge post-LC suggests need for further educational efforts. Participants identified “Tumor-specific considerations” as the main resource missing for PD-L1 testing. Conclusion A learning collaborative has shown impact in improving PD-L1 testing processes and related practices among a group of pathology professionals. The group successfully made available three panel videos and a resource guide, and PD-L1-related practice changes were reported. Future initiatives should address remaining gaps and develop tumor-specific PD-L1 testing considerations.

Integrated bioinformatics analysis and experimental validation on malignant progression and immune cell infiltration of LTBP2 in gliomas

BackgroundGliomas are the highly aggressive brain tumor and also the most devastating human tumors. The latent TGF binding proteins (LTBP) had been found to be involved in malignant biological process and could be used as potent biomarkers in several solid tumors. While the role of LTBP family in human glioma remain to be elucidated.MethodsNormalized gene expression and corresponding clinical data of 2407 gliomas samples in public datasets were downloaded from Gliovis. Kaplan–Meier methods and Cox regression analysis was used for survival analyses.Western blot (WB) and Immunohistochemical (IHC) testing were employed to test LTBPs protein level in 154 gliomas samples. Correlation between LTBP2 expression and immune infiltration was evaluated by immunofluorescence (IF) and IHC in glioma tissues. CCK8 and flow cytometric analysis were used to detect the effect of LTBP2 on glioma cells. Orthotopic glioma- mouse models were utilized to evaluate effects in vivo.ResultsLTBP2 mRNA level was dramatically higher in glioma samples compared with non-tumor brain tissues in XENA-TCGA_GTEx, Gill and Gravendeel datasets (all P < 0.01), and its expression positively correlated with glioma WHO grade, IDH1/2 wildtype and mesenchymal subtypes. These results were confirmed by In-house cohort which was detected by WB and IHC. We found that gliomas patients with high LTBP2 level had shorter OS than those with low LTBP2 level. LTBP2 expression significantly associated with glioma immune score (Spearman r = 0.68, P < 0.01)) and strongly correlated with infiltration degreee of macrophages both in lower grade gliomas (LGG) and GBM. Knocking down LTBP2 obviously reduced proliferation and enhanced sensitivity to temozolomide in U87 and U251 cells. Nude mice with lower expression of LTBP2 had slower tumor growth, and accompanied by less tumor-associated macrophages (TAMs) infiltration detected by IHC staining in vivo. Finally, low LTBP2 expression glioma patients who received chemotherapy survived longer than patients with high LTBP2 expression.ConclusionLTBP2 could be used as a prognostic marker, and high LTBP2 expression related to abundant TAMs infiltration and with a worse response to chemotherapy.

High cadmium exposure impairs adult hippocampal neurogenesis via disruption of store-operated calcium entry

Cadmium (Cd) is a neurotoxicant that gradually accumulates in the human body with age. High Cd burden is correlated with adult hippocampal neurogenesis (AHN) and memory deficits in mammals. However, little knowledge is known about the mechanism by which Cd exposure impairs neurogenesis and cognition. Here, we investigated the roles of store-operated calcium entry (SOCE)-mediated calcium dyshomeostasis in Cd-induced AHN and memory deficits as well as therapeutic potential for the prevention of Cd-induced neurotoxicity. To achieve this goal, 8 weeks-old C57BL/6 J mice were subjected to different concentrations of cadmium chloride (0, 5, 10, 20 ppm) in drinking water for 8 weeks, we then examined the AHN, calcium homeostasis, SOCE channel and memory in Cd-exposed mice by using immunohistochemistry, calcium imaging, Y-maze and fear conditioning test. Our results indicated that chronic Cd exposure markedly increased Cd levels in serum and cerebrospinal fluid by almost 10-fold, and inhibited the proliferation and differentiation of hippocampal adult neural stem cells in a dose-dependent manner. Additionally, Cd exposure impaired the maturation of hippocampal neural stem cells without inducing gliosis. Transcriptome analysis revealed that Cd exposure inhibited the proliferation of neuroblastoma via alteration of calcium signaling pathway, and attenuated SOCE channels played a pivotal role in mediating Cd-induced cytoplasmic calcium overload and depletion of endoplasmic reticulum calcium stores. Activation of SOCE by hyperforin, a natural derivative from medicinal plant, restored intracellular calcium homeostasis and improved AHN and memory in Cd-exposed mice. Together, this study provided novel insights into the mechanism that Cd exposure impaired AHN and memory by prompting neuronal SOCE-mediated calcium dyshomeostasis, and offered a new therapeutic approach for prevention of Cd-induced neurotoxicity.

Mechanical Stress-Oxidative Stress Axis: Biological Basis in the Vaginal Wall and Pelvic Floor Muscles of Rats with Simulated Birth Injury.

Vaginal delivery and resulting pelvic floor muscle (PFM) dysfunction are significant risk factors for pelvic floor dysfunction (PFD). Despite this, the biological basis underlying PFD after childbirth remain unclear. This study was aimed at assessing the early response of the vaginal wall and PFM to simulated birth injury (SBI) in rats. Forty female Sprague-Dawley rats were divided into four groups: control (sham operation), and 1, 4, and 14days post-injury. In the SBI groups, a catheter was inserted into the vagina with 130g of weight attached to the end, and the balloon was inflated to 5ml for 2h. Evaluation of vaginal tissues and PFMs included histological, immunohistochemical, Western blot, and uniaxial biomechanical testing. In the vaginal wall, the SBI group showed significantly lower COL1A1 expression and higher MMP-2 and MMP-9 expression. At 4 and 14days post-injury, there was a significant decrease in PFM fiber area and increased collagen content. The SBI group also exhibited significant increases in the expression of Nrf2, NQO1, HO-1, and SOD-2, indicating involvement of oxidative stress in both the vaginal wall and PFMs. Protein expression of Pax7 and MyoG, as well as the number of fibers with centralized nuclei, continued to increase significantly after SBI. Additionally, the vaginal wall of the SBI group showed a decreasing trend in tensile strength and elastic modulus, with a greater ultimate strain. Extracellular matrix remodeling, oxidative stress, decreased biomechanical properties, and muscle dysmyogenesis may collectively contribute to increased susceptibility to PFD development.

7582 Genetic Profiling of Phosphaturic Mesenchymal Tumors Unravels Osterix's Significance in Tumor-Induced Osteomalacia

Abstract Disclosure: Y. Imanishi: None. Y. Nagata: None. M. Ohara: None. T. Maeda-Tateishi: None. T. Shoji: None. M. Emoto: None. Background &amp; Purpose: Tumor-induced osteomalacia (TIO) is a rare condition caused by tumors releasing too much fibroblast growth factor 23 (FGF23). These tumors, specifically called phosphaturic mesenchymal tumors, mixed connective tissue variant (PMTMCT), lead to osteomalacia due to low serum phosphate levels. However, a detailed study regarding the genetic makeup of these tumors and their similarity to bone cells (osteoblasts/osteocytes) has been lacking. Methods: Nineteen PMTMCTs were analyzed and compared their gene expressions to 6 non-TIO tumors. Our focus was on genes usually found in bone cells. Additionally, we examined the relationship between FGF23 and these genes in PMTMCTs. One gene, Osterix, showing significant correlation was further studied using UMR106 osteoblast cells. Results: Fourteen genes related to bone cells expressed significantly higher in PMTMCTs compared to non-TIO tumors. Immunoblotting and Immunohistochemical examinations confirmed the presence of FGF23, Runx2, and Osterix in PMTMCTs. Particularly, Osterix showed the strongest link with FGF23 in PMTMCTs. Immunohistochemical tests revealed similar patterns of distribution for Osterix and FGF23, even co-localizing in some instances. However, the distribution of another gene, DMP1, differed from that of FGF23. In UMR106 cells, silencing Osterix expression led to decreased FGF23 expression, irrespective of DMP1 levels. Conclusions: PMTMCTs exhibit higher levels of genes associated with bone cell functions compared to other tumors. These tumors likely originated from mesenchymal stem cells and transformed into bone cells. Furthermore, Osterix might play a crucial role in the excessive release of FGF23 in PMTMCTs. Presentation: 6/1/2024

7242 Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) In A Patient With Recurrent Carcinoid

Abstract Disclosure: F. Woron: None. T.L. Anderson: None. P. Madhavan: None. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare generalized proliferation of pulmonary neuroendocrine cells. It is considered to be a pre-invasive lesion for pulmonary carcinoid, a rare neuroendocrine tumor (NET). DIPNECH is thought to be underdiagnosed, as patients can be asymptomatic or present with nonspecific cough and dyspnea, though it is also associated with fibrotic lung changes. Long-term annual surveillance imaging is recommended for due to the potential for development and metastasis of carcinoid tumors. We present a patient with recurrent pulmonary carcinoid later diagnosed with probable DIPNECH based on CT findings. The patient is a 72-year-old female with a prior 15 pack-year smoking history, who initially had a left lower lobe typical carcinoid tumor diagnosed and resected in 2018, with no evidence of lymph node metastasis. The patient’s medical history also includes pulmonary sarcoidosis, adrenal adenoma, thyroid nodule, hiatal hernia, and prediabetes. She has no family history of neuroendocrine tumors. Physical exam showed stable vitals with blood pressure of 112/70 mmHg in the right upper arm, heart rate of 84 bpm, and a body mass index of 39. Physical exam was unremarkable except for thyroid nodularity and obesity. Extensive biochemical evaluation for markers including chromogranin A and 24-hour urine 5-HIAA levels were within normal limits. In 2022, surveillance CT imaging showed a new 9 mm nodule in the right lobe within the bronchus, which was shown to be carcinoid on FNA. She complained of dyspnea and wheezing at this time, which has been managed with an albuterol inhaler. In 2023, PET/CT copper 64 dotatate scan showed a focal area of activity related to the nodule in the superior segment, also identified on recent CT scan, with the nodule measuring approximately 2.05 cm x 1.8 cm with a maximal SUV of 4.2. Interestingly, somatostatin receptor scintigraphy did not show any pick-up in the lung in 2018 or 2022. In 2023, the patient underwent right lower lobe superior segmentectomy after the nodule was found to have increased in size. Pathology showed G1, well-differentiated 1.1 cm typical carcinoid tumor with margins negative for invasive carcinoma. All 18 regional lymph nodes were negative for tumor. Immunohistochemical tests show that the tumor cells were positive for INSM1 and chromogranin with a low Ki-67 proliferation index (&amp;lt;2%), supporting the diagnosis. The patient is currently being monitored by yearly CT imaging and followed by both endocrinology and pulmonology. Given this case, we propose that DIPNECH should be considered as a differential in cases of pulmonary carcinoid, especially recurrent ones. Given that DIPNECH is thought to be underdiagnosed and a precursor for carcinoid associated with fibrotic lung changes, it is essential for this disease to be identified in order for patients to receive appropriate long-term monitoring. Presentation: 6/1/2024

Deep learning model with pathological knowledge for detection of colorectal neuroendocrine tumor

Colorectal neuroendocrine tumors (NETs) differ significantly from colorectal carcinoma (CRC) in terms of treatment strategy and prognosis, necessitating a cost-effective approach for accurate discrimination. Here, we propose an approach for distinguishing between colorectal NET and CRC based on pathological images by utilizing pathological prior information to facilitate the generation of robust slide-level features. By calculating the similarity between morphological descriptions and patches, our approach selects only 2% of the diagnostically relevant patches for both training and inference, achieving an area under the receiver operating characteristic curve (AUROC) of 0.9974 on the internal dataset, and AUROCs of 0.9724 and 0.9513 on two external datasets. Our model effectively identifies NETs from CRCs, reducing unnecessary immunohistochemical tests and enhancing the precise treatment for patients with colorectal tumors. Our approach also enables researchers to investigate methods with high accuracy and low computational complexity, thereby advancing the application of artificial intelligence in clinical settings.

Poor compliance with germline testing recommendations in colorectal cancer patients undergoing molecular residual disease testing.

Approximately 15% of colorectal cancers (CRCs) are associated with germline mutations. There is increasing adoption of DNA-based assays for molecular residual disease (MRD) and growing evidence supporting its clinical utility, particularly for CRC by oncologists in the U.S. We assessed the uptake of germline multi-gene panel testing (MGPT) for hereditary cancer in CRC patients receiving MRD analyses in community oncology settings. This retrospective study included 80 patients receiving care for CRC through community oncology practices who were referred for MRD testing at a commercial laboratory (January-March 2022). Clinical data, including test requisition forms, pathology reports, and clinical notes were reviewed. Documentation of tumor microsatellite instability and/or immunohistochemical (IHC) testing for mismatch repair (MMR) deficiency, age of CRC diagnosis, family history of cancer, and any order or recommendation for MGPT were assessed. Overall, 5/80 (6.3%) patients in the study have documented germline MGPT; 65/80 (81.3%) patients have documented MMR testing of their colorectal tumor. Among the 5 cases with abnormal MMR IHC, 2 have MGPT. Of the 33 patients meeting the 2021 National Comprehensive Cancer Network (NCCN) criteria for genetic/familial high-risk assessment, only 2 have MGPT. Our real-world data suggest that many CRC patients receiving MRD testing and meeting NCCN (v. 2021) criteria for germline MGPT may not be receiving evaluation beyond routine MMR status. Process and educational improvements are needed in community health settings to increase access and uptake of germline testing among CRC patients regardless of age at diagnosis or MMR status.