Antibacterial activity and mechanisms of D-3263 against Staphylococcus aureus.

Multi-drug-resistant Staphylococcus aureus infections necessitate novel antibiotic development. D-3263, a transient receptor potential melastatin member 8 (TRPM8) agonist, has potential antineoplastic properties. Here, we reported the antibacterial and antibiofilm activities of D-3263. Minimum inhibitory concentrations (MICs) against S. aureus, Enterococcus faecalis and E. faecium were ≤ 50 µM. D-3263 exhibited bactericidal effects against clinical methicillin-resistant S. aureus (MRSA) and E. faecalis strains at 4× MIC. Subinhibitory D-3263 concentrations effectively inhibited S. aureus and E. faecalis biofilms, with higher concentrations also clearing mature biofilms. Proteomic analysis revealed differential expression of 29 proteins under 1/2 × MIC D-3263, influencing amino acid biosynthesis and carbohydrate metabolism. Additionally, D-3263 enhanced membrane permeability of S. aureus and E. faecalis. Bacterial membrane phospholipids phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and cardiolipin (CL) dose-dependently increased D-3263 MICs. Overall, our data suggested that D-3263 exhibited potent antibacterial and antibiofilm activities against S. aureus by targeting the cell membrane.

Profiling of the genetic features of Chinese patients with gastric cancer with HRD germline mutations in a large-scale retrospective study.

BACKGROUND: Approximately 10% of gastric cancers (GCs) are associated with strong familial clustering and can be attributed to genetic predisposition. Homologous recombination deficiency (HRD) leads to genomic instability and accumulation of genetic variations, playing an important role in the development and progression of cancer. We aimed to delineate the germline mutation characteristics of patients with HRD-mut GC in Chinese. METHODS: We retrospectively reviewed the genomic sequencing data of 1135 patients with Chinese GC. Patients harbouring at least one loss of function (LoF) germline mutations in BRCA1, BRCA2, ATM, PALB2, BRIP1, CHEK1, CHEK2, FANCA and FANCL were selected for analysis. RESULTS: 89 patients were identified with LoF germline mutations of HRD gene. Germline mutations occurred most commonly in ATM (30.33%), followed by BRIP1 (17.98%), BRCA2 (14.61%), BRCA1 (12.36%), FANCA (10.11%), PALB2 (10.11%), FANCL (6.74%), CHEK1 (3.37%) and CHEK2 (3.37%). 14 out of 89 patients with HRD-mut harboured double mutations in HRD and MMR genes, with the median age of 51.5 years. The decreasing median age would be attributed to five patients with HRD+MMR double-muts harbouring mutations in both HRD and MMR genes. The median age of onset of patients with HRD+MMR double-muts is 47, which is significantly earlier than that of Chinese patients with GC (p=0.0235). CONCLUSION: Our data suggest that carrying both HRD and MMR gene LoF germline mutations may cause early-onset GC. Germline mutations in the HRD gene should be of concern in the study of hereditary GC.

Incidental findings during donor liver assessment: Single center experience.

Intraoperative consultation of donor liver is an important part of transplant evaluation and determination of liver eligibility. In this study, we describe incidental pathologic findings discovered during the pretransplant evaluation of liver donors in our Institution from 1/2010 to 12/2022. During this 13-year period 369 intraoperative consultations from 262 liver donors were performed. Of those cases, incidental findings were identified in 22 cases (5.9 %) from 19 donors (7.3 %); two donors had more than one lesion. The median age of this subset of patients was 53 years (range: 18-70) and females predominated (63 %). Sixteen of the donors had abnormal findings in the liver: 6 bile duct hamartoma (BDH), 5 hyalinized nodule with Histoplasma capsulatum, 5 focal nodular hyperplasia (FNH), 2 bile duct adenomas (BDA), 1 biliary cyst and 1 hemangioma. One donor had both FNH and a BDH. One BDH and 1 BDA case was misdiagnosed as malignancy during the frozen section evaluation. Three donors had extrahepatic pathologies: a pancreatic tail schwannoma, a low-grade appendiceal mucinous neoplasm, and a lymph node with metastatic endometrial endometrioid adenocarcinoma. Of the 19 livers, the final organ disposition was available for 9: 6 were transplanted (67 %) and 3 were discarded (33 %). Two of the 3 discarded organs were misdiagnosed BDH and BDA cases, and one was incorrectly reported as having 90 % microvesicular steatosis during the frozen assessment. We present the clinicopathologic characteristics of liver donors with incidental findings during the pre-transplant evaluation which could lead to unwarranted graft dismissal if misdiagnosed. Additionally, incidental fungal infections can have implications for immunosuppressive therapy and the decision to use or reject the graft.

Changes of cardiac output and velocity time integral in blood return at the end of renal replacement therapy predict fluid responsiveness in critically Ill patients with acute circulatory failure.

OBJECTIVES: To observe if blood return, also defined as the blood infusion test (BIT) could predict fluid responsiveness in critically ill patients with acute circulatory failure and renal replacement therapy (RRT). METHODS: This was a single-center, prospective, diagnostic accuracy study. Before BIT, the passive leg raise test (PLRT) was performed to record the change of cardiac output (ΔCO) by pulse contour analysis, and ΔCO > = 10% was defined as the fluid responder. Meanwhile, the change in velocity time integral (ΔVTI) was recorded by ultrasound. Later, the ΔCO and ΔVTI during BIT were recorded 5-10 min after PLRT. The receiver-operating characteristic curves of ΔCO and ΔVTI of BIT were performed in predicting the fluid responder defined by PLRT. RESULTS: A total of 43 patients with acute circulatory failure undergoing RRT were enrolled in the present study, and 25 patients (58.1%) were recognized as responders during PLRT. According to the receiver-operating characteristic curves, the cutoff value of ΔCO was 10% and ΔVTI was 9% during BIT with the area under curve of 0.96 and 0.94, respectively. CONCLUSIONS: BIT in RRT could identify fluid responsiveness in critically ill patients with shock. TRIAL REGISTRATION: ChiCTR-DDD-17010534. Registered on 30/01/2017 (retrospective registration).

Development and evaluation of a rapid CRISPR-based diagnostic for COVID-19.

The recent outbreak of human infections caused by SARS-CoV-2, the third zoonotic coronavirus has raised great public health concern globally. Rapid and accurate diagnosis of this novel pathogen posts great challenges not only clinically but also technologically. Metagenomic next-generation sequencing (mNGS) and reverse-transcription PCR (RT-PCR) have been the most commonly used molecular methodologies. However, each has their own limitations. In this study, we developed an isothermal, CRISPR-based diagnostic for COVID-19 with near single-copy sensitivity. The diagnostic performances of all three technology platforms were also compared. Our study aimed to provide more insights into the molecular detection of SARS-CoV-2, and also to present a novel diagnostic option for this new emerging virus.

Ferroptosis-related gene SLC1A5 is a novel prognostic biomarker and correlates with immune infiltrates in stomach adenocarcinoma.

BACKGROUND: Stomach adenocarcinoma (STAD) is associated with high morbidity and mortality rates. Ferroptosis is an iron-dependent form of cell death, which plays an important role in the development of many cancers. Tumor-associated competing endogenous RNAs (ceRNAs) regulate tumorigenesis and development. Our study aimed to construct ceRNA networks and explore the relationship between ferroptosis-related genes in the ceRNA network and immune infiltration in STAD. METHODS: Based on the interactions among long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs), a ceRNA network was constructed to illustrate the relationships among lncRNAs, miRNAs, and mRNAs. Subsequently, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) functional enrichment analyses were carried out to explore the functions and interactions of the differentially expressed (DE) mRNAs related to the ceRNA network. Differential expression and prognostic analysis of ferroptosis-related genes in the ceRNA network were performed using the R package "limma" and "survminer." The correlation between ferroptosis-related genes and tumor-infiltrating immune cells was analyzed using Spearman correlation analysis and CIBERSORT. Quantitative real-time PCR (qRT-PCR) was used to validate the expression of ferroptosis-related genes in STAD cells lines. RESULTS: A ceRNA network consisting of 29 DElncRNAs, 31 DEmiRNAs, and 182 DEmRNAs was constructed. These DEmRNAs were significantly enriched in pathways related to the occurrence and development of STAD. The ferroptosis-related gene SLC1A5 was upregulated in STAD (P < 0.001) and was associated with better prognosis (P = 0.049). The CIBERSORT database and Spearman correlation analysis indicated that SLC1A5 was correlated with eight types of tumor-infiltrating immune cells and immune checkpoints, including PD-L1(CD-274) and PD-1(PDCD1). The SLC1A5 mRNA was found to be highly expressed in STAD cells lines. CONCLUSIONS: Our study provides insights into the function of ceRNAs in STAD and identifies biomarkers for the development of therapies for STAD. The ferroptosis-related gene SLC1A5 in the ceRNA network was associated with both tumor-infiltrating immune cells and immune checkpoints in the tumor microenvironment, suggesting that SLC1A5 may be a novel prognostic marker and a potential target for STAD immunotherapy in the future.

Epitope Selection for HLA-DQ2 Presentation: Implications for Celiac Disease and Viral Defense.

We have reported that the major histocompatibility molecule HLA-DQ2 (DQA1*05:01/DQB1*02:01) (DQ2) is relatively resistant to HLA-DM (DM), a peptide exchange catalyst for MHC class II. In this study, we analyzed the role of DQ2/DM interaction in the generation of DQ2-restricted gliadin epitopes, relevant to celiac disease, or DQ2-restricted viral epitopes, relevant to host defense. We used paired human APC, differing in DM expression (DMnull versus DMhigh) or differing by expression of wild-type DQ2, versus a DM-susceptible, DQ2 point mutant DQ2α+53G. The APC pairs were compared for their ability to stimulate human CD4+ T cell clones. Despite higher DQ2 levels, DMhigh APC attenuated T cell responses compared with DMnull APC after intracellular generation of four tested gliadin epitopes. DMhigh APC expressing the DQ2α+53G mutant further suppressed these gliadin-mediated responses. The gliadin epitopes were found to have moderate affinity for DQ2, and even lower affinity for the DQ2 mutant, consistent with DM suppression of their presentation. In contrast, DMhigh APC significantly promoted the presentation of DQ2-restricted epitopes derived intracellularly from inactivated HSV type 2, influenza hemagglutinin, and human papillomavirus E7 protein. When extracellular peptide epitopes were used as Ag, the DQ2 surface levels and peptide affinity were the major regulators of T cell responses. The differential effect of DM on stimulation of the two groups of T cell clones implies differences in DQ2 presentation pathways associated with nonpathogen- and pathogen-derived Ags in vivo.

Colon perforation due to cytomegalovirus infection in a patient with idiopathic hypereosinophilic syndrome: a case report.

BACKGROUND: Hypereosinophilic syndrome (HES) is a very rare disease and usually treated with corticosteroids. Gastrointestinal (GI) cytomegalovirus (CMV) infection is also rare but frequent in patients with immunocompromised status. These two related diseases present with similar manifestations, and may result in a life-threatening complication: perforation. However, the treatment strategies differ greatly. Here, we report a case of colon perforation due to cytomegalovirus infection in a patient with idiopathic HES. CASE PRESENTATION: A 41-year-old man with a history of HES was transferred to our hospital due to an acute onset of abdominal pain. During the treatment course of HES, this patient received CMV-DNA test with a result of < 2000 copies/ml. Computed tomography (CT) suggested colon perforation. An emergency surgery was performed immediately. Pathological diagnosis revealed CMV infection and infiltration of eosinophils. This patient received both anti-CMV therapy and immunosuppression therapy. Subsequently, the patient recovered and was discharged 25 days after the operation. CONCLUSION: During the course of HES treatment, CMV infection should be reconsidered if digestive symptoms relapse.

Combining Serum Cystatin C and Urinary N-Acetyl-Beta-D-Glucosaminidase Improves the Precision for Acute Kidney Injury Diagnosis after Resection of Intracranial Space-Occupying Lesions.

BACKGROUND: Postoperative acute kidney injury (AKI) is frequent and associated with adverse outcomes. Unfortunately, the early diagnosis of AKI remains a challenge. Combining functional and tubular damage biomarkers may provide better precision for AKI detection. However, the diagnostic accuracy of this combination for AKI after neurosurgery is unclear. Serum cystatin C (sCysC) and urinary albumin/creatinine ratio (uACR) are considered functional biomarkers, while urinary N-acetyl-ß-D-glucosaminidase (uNAG) represents tubular damage. We aimed to assess the performances of these clinical available biomarkers and their combinations for AKI prediction after resection of intracranial space-occupying lesions. METHODS: A prospective study was conducted, enrolling adults undergoing resection of intracranial space-occupying lesions and admitted to the neurosurgical intensive care unit. The discriminative abilities of postoperative sCysC, uNAG, uACR, and their combinations in predicting AKI were compared using the area under the receiver operating characteristic curve (AUC-ROC), continuous net reclassification index (cNRI), and incremental discrimination improvement (IDI). RESULTS: Of 605 enrolled patients, AKI occurred in 67 patients. The cutoff values of sCysC, uNAG, and uACR to predict postoperative AKI were 0.72 mg/L, 19.98 U/g creatinine, and 44.21 mg/g creatinine, respectively. For predicting AKI, the composite of sCysC and uNAG (AUC-ROC = 0.785) outperformed either individual biomarkers or the other two panels (uNAG plus uACR or sCysC plus uACR). Adding this panel to the predictive model improved the AUC-ROC to 0.808. Moreover, this combination significantly improved risk reclassification over the clinical model alone, with cNRI (0.633) and IDI (0.076). Superior performance of this panel was further confirmed with bootstrap internal validation. CONCLUSIONS: Combination of functional and tubular damage biomarkers improves the predictive accuracy for AKI after resection of intracranial space-occupying lesions.

The influence of glycemic status on the performance of cystatin C for acute kidney injury detection in the critically ill.

OBJECTIVE: Serum cystatin C (sCysC) used clinically for detecting early acute kidney injury (AKI) was reported to be independently associated with hemoglobin (HbA1c) levels, diabetes, and prediabetes. We aimed to assess the influence of HbA1c levels, diabetes, or prediabetes on the performance of sCysC for AKI detection in critically ill adults. METHODS: A prospective observational study was conducted in a mixed medical-surgical intensive care unit (ICU). Patients were divided into four quartiles based on levels of HbA1c or serum glucose at ICU admission, respectively. Additionally, patients were stratified into four subgroups according to HbA1c levels and history of diabetes, namely recognized diabetes (previous diagnosis of diabetes), unrecognized diabetes, prediabetes, and normal glycemic status. Comparisons were made using the area under the receiver operator characteristic curve (AUC) for AKI detection, and reassessed after patient stratification by above-mentioned glycemic status. RESULTS: Multivariable linear regression revealed that HbA1c levels and history of diabetes were positively related with sCysC (all p < .05). Although stratification for above-mentioned glycemic status displayed no significant difference between AUC of sCysC (all p > .05), sCysC yielded the highest AUCs for detecting AKI in diabetic patients. Moreover, higher optimal cutoff values of sCysC to detect AKI were observed in patients with versus without diabetes. CONCLUSION: Glycemic status has no significant impact on the accuracy of sCysC for AKI detection in critically ill adults and a higher optimal cutoff value of sCysC for AKI detection should be considered in diabetic patients.

Cytopathology and clinicopathological correlation of renal neuroendocrine neoplasms.

INTRODUCTION: There is a lack of documentation regarding cytopathology of renal neuroendocrine neoplasms (NENs) due to their rarity. MATERIALS AND METHODS: Five cytology cases were gathered from 3 institutes. RESULTS: Cohort consisted of 4 females and 1 male. Fine needle aspiration biopsy and touch preparation slides of core needle biopsy revealed cellular samples, composed of round, plasmacytoid, or columnar cells. Tumor cells were present in nested, acinar, 3D cluster, and individual cell patterns. Tumor cells in 3 cases exhibited uniformly round to oval small nuclei with inconspicuous nucleoli, finely granular chromatin, and smooth nuclear membranes, whereas 2 other cases showed pleomorphic nuclei with conspicuous nucleoli, nuclear molding, and irregular nuclear membranes. Tumor cells displayed pale or granular cytoplasm, with 1 case showing small vacuoles. Examination of cores and cell blocks demonstrated tumor cells in sheets, nests, or acini. All tumor cells were positive for neuroendocrine immunomarkers. Based on mitotic count, Ki-67 index and morphology, 3 tumors were graded as well-differentiated neuroendocrine tumor (WDNET) (1 grade [G] 3, 1 G2, 1 G1) and 2 as large cell neuroendocrine carcinoma. Deletion of 7q, 10q, and 19q was detected in WDNETs. Two patients with large cell neuroendocrine carcinoma and 1 with WDNET G3 underwent chemotherapy due to aggressiveness, whereas nephrectomy was performed for patients with WDNET G1 and 2 without metastasis. CONCLUSIONS: Cytopathological characteristics of renal NENs closely resemble those affecting other organs. Despite its rarity, renal NENs should be kept in mind when confronted with morphological resemblances to NENs, to prevent misdiagnosis and inappropriate therapeutic interventions.

Invasive Fungal Infections of the Head and Neck: A Tertiary Hospital Experience.

From the existing millions of fungal species, only a few cause disease. In this study, we investigated invasive fungal infections in the head and neck (H&N) over a 19-year period (2005 to 2024) at a large academic healthcare system. Among the 413 documented fungal H&N infections, 336 were noninvasive, and 77 were invasive. The highest incidence of invasive infections occurred in the sinonasal cavities, with a 15-fold difference compared to other sites. Most infections affected adults over 40 years old. The most common organisms were Mucorales (51%), hyaline molds (29%), and Candida (11%). Risk factors included malignancy, transplant, diabetes, and illicit drug use. Mortality was high in patients with malignancy and/or transplant. Infections affecting the mandible were usually a complication of osteoradionecrosis and were associated with the coinfection of Candida and Actinomyces. At other sites, infections were rare and were usually the result of penetrating injuries or immunosuppression. Treatment typically involved a combination of antifungals and surgical procedures.

DEPDC1B: A novel tumor suppressor gene associated with immune infiltration in colon adenocarcinoma.

BACKGROUND: Recent research indicates a positive correlation between DEP structural domain-containing 1B (DEPDC1B) and the cell cycle in various tumors. However, the role of DEPDC1B in the infiltration of the tumor immune microenvironment (TIME) remains unexplored. METHODS: We analyzed the differential expression and prognostic significance of DEPDC1B in colon adenocarcinoma (COAD) using the R package "limma" and the Gene Expression Profiling Interactive Analysis (GEPIA) website. Gene set enrichment analysis (GSEA) was employed to investigate the functions and interactions of DEPDC1B expression in COAD. Cell Counting Kit-8 (CCK-8) assays and colony formation assays were utilized to assess the proliferative function of DEPDC1B. Correlations between DEPDC1B expression and tumor-infiltrating immune cells, immune checkpoints, tumor mutational burden (TMB), and microsatellite instability (MSI) status were examined using Spearman correlation analysis and CIBERSORT. RESULTS: DEPDC1B was highly expressed in COAD. Elevated DEPDC1B expression was associated with lower epithelial-to-mesenchymal transition (EMT) and TNM stages, leading to a favorable prognosis. DEPDC1B mRNA was prominently expressed in COAD cell lines. CCK-8 and colony formation assays demonstrated that DEPDC1B inhibited the proliferation of COAD cells. Analysis using the CIBERSORT database and Spearman correlation revealed that DEPDC1B correlated with four types of tumor-infiltrating immune cells. Furthermore, high DEPDC1B expression was linked to the expression of PD-L1, CTLA4, SIGLEC15, PD-L2, TMB, and MSI-H. High DEPDC1B expression also indicated responsiveness to anti-PD-L1 immunotherapy. CONCLUSIONS: DEPDC1B inhibits the proliferation of COAD cells and positively regulates the cell cycle, showing a positive correlation with CCNB1 and PBK expression. DEPDC1B expression in COAD is associated with tumor-infiltrating immune cells, immune checkpoints, TMB, and MSI-H in the tumor immune microenvironment. This suggests that DEPDC1B may serve as a novel prognostic marker and a potential target for immunotherapy in COAD.

Metastatic germ cell tumors in serous cavities and cerebrospinal fluid: A single-center experience.

BACKGROUND: Metastatic germ cell tumors (GCTs) involving body cavity effusions and cerebrospinal fluid (CSF) are rare. Diagnosis is challenging because of limited morphological and clinicopathological information in the literature. METHODS: A database search of our institution from 1990 to 2024 identified 27 cases of metastatic GCTs, comprising five pediatric and 22 adolescent and adult patients, in serous cavities or the CSF, including peritoneal (15), pleural (nine), CSF (two), and pericardial (one) fluid. RESULTS: The most common primary site was the testis (n = 10), followed by the ovaries (n = 7), mediastinum (n = 4), retroperitoneum (n = 3), pineal gland (n = 2), and sacrum/coccyx (n = 1). The primary tumors in 14 patients were mixed GCTs (six with a seminoma component), followed by immature teratomas (six), yolk sac tumors (three), embryonal carcinomas (two), pure seminomas (one), and postpubertal teratomas (one). The median interval between primary tumor diagnosis and diagnosis of fluid positivity was 7 months (range: 0-134 months). In nine cases, the malignant fluid was diagnosed simultaneously with or within 1 month of the primary tumor. GCT subtyping was performed on 23 of the 27 cytological specimens. Twenty-four patients (89%) also had metastases to other sites. Thirteen patients died of the disease (48%), with a median survival time of 4 months. CONCLUSIONS: Metastatic GCTs in serous effusions and CSF are often associated with disseminated disease and poor prognosis. Subtyping can be performed by cytomorphology combined with immunohistochemistry.

KDM3A Ablation Activates Endogenous Retrovirus Expression to Stimulate Antitumor Immunity in Gastric Cancer.

The success of immunotherapy for cancer treatment is limited by the presence of an immunosuppressive tumor microenvironment (TME); Therefore, identifying novel targets to that can reverse this immunosuppressive TME and enhance immunotherapy efficacy is essential. In this study, enrichment analysis based on publicly available single-cell and bulk RNA sequencing data from gastric cancer patients are conducted, and found that tumor-intrinsic interferon (IFN) plays a central role in TME regulation. The results shows that KDM3A over-expression suppresses the tumor-intrinsic IFN response and inhibits KDM3A, either genomically or pharmacologically, which effectively promotes IFN responses by activating endogenous retroviruses (ERVs). KDM3A ablation reconfigures the dsRNA-MAVS-IFN axis by modulating H3K4me2, enhancing the infiltration and function of CD8 T cells, and simultaneously reducing the presence of regulatory T cells, resulting in a reshaped TME in vivo. In addition, combining anti-PD1 therapy with KDM3A inhibition effectively inhibited tumor growth. In conclusions, this study highlights KDM3A as a potential target for TME remodeling and the enhancement of antitumor immunity in gastric cancer through the regulation of the ERV-MAVS-IFN axis.

An insertion mutant in DQA1*0501 restores susceptibility to HLA-DM: implications for disease associations.

HLA-DM (DM) catalyzes CLIP release, stabilizes MHC class II molecules, and edits the peptide repertoire presented by class II. Impaired DM function may have profound effects on Ag presentation events in the thymus and periphery that are critical for maintenance of self-tolerance. The associations of the HLA-DQ2 (DQ2) allele with celiac disease and type 1 diabetes mellitus have been appreciated for a long time. The explanation for these associations, however, remains unknown. We previously found that DQ2 is a poor substrate for DM. In this study, to further characterize DQ2-DM interaction, we introduced point mutations into DQ2 on the proposed DQ2-DM interface to restore the sensitivity of DQ2 to DM. The effects of mutations were investigated by measuring the peptide dissociation and exchange rate in vitro, CLIP and DQ2 expression on the cell surface, and the presentation of α-II-gliadin epitope (residues 62-70) to murine, DQ2-restricted T cell hybridomas. We found that the three α-chain mutations (α+53G, α+53R, or αY22F) decreased the intrinsic stability of peptide-class II complex. More interestingly, the α+53G mutant restored DQ2 sensitivity to DM, likely due to improved interaction with DM. Our data also suggest that α-II-gliadin 62-70 is a DM-suppressed epitope. The DQ2 resistance to DM changes the fate of this peptide from a cryptic to an immunodominant epitope. Our findings elucidate the structural basis for reduced DQ2-DM interaction and have implications for mechanisms underlying disease associations of DQ2.

Morphologic Changes in the Thymus Following Chemotherapy for Anterior Mediastinal Germ Cell Tumors: A Study of 91 Cases Emphasizing Pseudoneoplastic Features.

CONTEXT.­: The interpretation of postchemotherapy resections of anterior mediastinal germ cell tumors plays a critical role in determining future patient management and prognosis. Treatment-related changes in the thymus may mimic residual teratoma or microcystic-pattern yolk sac tumor. There is limited extant information concerning therapy-related pseudoneoplastic thymic alterations. OBJECTIVE.­: To provide diagnostic assistance to distinguish nonneoplastic thymic abnormalities secondary to chemotherapy from residual germ cell tumor. DESIGN.­: We retrospectively reviewed 91 resections of primary anterior mediastinal germ cell tumors with recognizable thymic gland following cisplatin-based chemotherapy. RESULTS.­: The cohort included 90 men and 1 woman (median age, 29 years). A spectrum of thymic epithelial alterations occurred, including cystic change (macrocysts [n = 21] or microcysts [n = 20]); hyperplasia with reactive atypia (n = 8); ciliated, mucinous, or columnar cell metaplasia (n = 3); and mature squamous metaplasia (n = 2). These changes were similar to so-called acquired multilocular thymic cysts, were often contiguous with and adjacent to normal thymic epithelium, and lacked the neoplastic-type atypia seen in teratomatous elements in this setting. In 1 case, confluent microcysts closely mimicked the appearance of yolk sac tumor but lacked other distinctive features of that neoplasm and its characteristic immunoreactivity. CONCLUSIONS.­: Recognition of therapy-induced thymic changes is important to avoid misinterpretation as residual teratoma or yolk sac tumor. Continuity with and proximity to benign thymic epithelium, absence of neoplastic-type atypia, and awareness of this phenomenon are important in avoiding this pitfall.

Multifocal C-cell Hyperplasia and Marked Hypercalcitoninemia in a Diabetic Patient Treated With Glucagon-Like Peptide-1 Agonist With Concurrent Multinodular Goiter and Hyperparathyroidism.

Thyroid C-cell hyperplasia (CCH) is divided into physiologic or reactive CCH and neoplastic CCH. Glucagon-like peptide-1 receptor agonists (GLP-1 Ra) is a group of medications used to treat type 2 diabetes that has documented C-cell stimulation effect in rodents, leading to subsequent CCH and medullary thyroid carcinoma (MTC) in rats and/or mice. Currently, there is no sufficient evidence supporting the association between GLP-1 Ra and human thyroid CCH and/or MTC. Here, we present a case of significant hypercalcitoninemia in a 53-year-old diabetic male patient receiving GLP-1 Ra treatment with concurrent multinodular goiter and hyperparathyroidism. Total thyroidectomy and central neck dissection revealed multifocal CCH involving bilateral thyroid lobes and several negative lymph nodes. Subsequent genetic testing did not detect germline mutation of RET gene. However, due to marked hypercalcitoninemia and massive thyromegaly, unsampled medullary thyroid microcarcinoma cannot be completely ruled out. The patient's postsurgical calcitonin level was back to normal. Our case indicates the significant clinical value of monitoring serum calcitonin levels in patients receiving GLP-1 Ra, especially in presence of other thyroid and/or parathyroid pathology that may be associated with increased calcitonin and/or CCH. Literature regarding the association between GLP-1 Ra and CCH is also reviewed.

Comparison of PD-L1 IHC 22C3 PharmDx Combined Positive Score (CPS) in Primary Versus Metastatic Nodal Squamous Cell Carcinomas of the Head and Neck: Is There a Significant Difference?

PD-L1 IHC 22C3 pharmDx is an FDA-approved companion test to select patients for anti-PD-L1 immunotherapy. In head and neck squamous cell carcinoma PD-L1 expression is determined using a Combined Positive Score (CPS), which evaluates expression in tumor cells and tumor-associated leukocytes. We hypothesized that in nodal metastasis, the CPS should be higher given their inherent higher proportion of leukocytes. A significant difference in CPS between sites would mean that the tissue chosen for PD-L1 testing would impact patient eligibility for therapy. Currently, guidelines about which tissue should be tested do not exist. PD-L1 22C3 IHC was performed in the primary and nodal metastases of 35 head and neck squamous cell carcinoma, and a CPS was generated by 3 pathologists. Mean CPS was higher at the primary than the nodal metastasis: 47.2 versus 42.2; however, the difference was not statistically significant: P=0.259 . By therapeutic groups: negative (CPS <1), low (CPS 1-19) and high (CPS≥20), low-expression was more common in the primary: 40 vs. 26%, and high-expression in the nodal metastasis: 74 vs. 60% but this difference was not statistically significant: P=0.180. Stratified by positive versus negative (CPS <1 vs. ≥1), there were no differences between sites. Interobserver agreement for CPS among the 3 raters was slight for both sites: ƙ = 0.117 and 0.025, fair if stratified by therapeutic group: ƙ = 0.371 and 0.318, and near perfect if stratified as negative versus positive: ƙ = 0.652 and 1. There were no statistically significant differences in CPS between primary and nodal metastases independent of how the CPS was stratified.