Enhanced Complement Expression in the Tumor Microenvironment Following Neoadjuvant Therapy: Implications for Immunomodulation and Survival in Pancreatic Ductal Adenocarcinoma.

Background: Neoadjuvant therapy (NAT) is increasingly being used for pancreatic ductal adenocarcinoma (PDAC) treatment. However, its specific effects on carcinoma cells and the tumor microenvironment (TME) are not fully understood. This study aims to investigate how NAT differentially impacts PDAC's carcinoma cells and TME. Methods: Spatial transcriptomics was used to compare gene expression profiles in carcinoma cells and the TME between 23 NAT-treated and 13 NAT-naïve PDAC patients, correlating with their clinicopathologic features. Analysis of an online single-nucleus RNA sequencing (snRNA-seq) dataset was performed for validation of the specific cell types responsible for NAT-induced gene expression alterations. Results: NAT not only induces apoptosis and inhibits proliferation in carcinoma cells but also significantly remodels the TME. Notably, NAT induces a coordinated upregulation of multiple key complement genes (C3, C1S, C1R, C4B and C7) in the TME, making the complement pathway one of the most significantly affected pathways by NAT. Patients with higher TME complement expression following NAT exhibit improved overall survival. These patients also exhibit increased immunomodulatory and neurotrophic cancer-associated fibroblasts (CAFs); more CD4+ T cells, monocytes, and mast cells; and reduced immune exhaustion gene expression. snRNA-seq analysis demonstrates C3 complement was specifically upregulated in CAFs but not in other stroma cell types. Conclusions: NAT can enhance complement production and signaling within the TME, which is associated with reduced immunosuppression in PDAC. These findings suggest that local complement dynamics could serve as a novel biomarker for prognosis, evaluating treatment response and resistance, and guiding therapeutic strategies in NAT-treated PDAC patients.

Improving fine needle aspiration to predict the tumor biological aggressiveness in pancreatic neuroendocrine tumors using Ki-67 proliferation index, phosphorylated histone H3 (PHH3), and BCL-2.

INTRODUCTION: Surgery is the only known cure for sporadic pancreatic neuroendocrine tumors (PNETs). Therefore, the prediction of the PNETs biological aggressiveness evaluated on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a significant impact on clinical management. The proliferation rate of Ki-67 in PNETs can help to predict the biological aggressiveness of the tumor. In addition, there is a relatively new proliferation marker called phosphorylated histone H3 (PHH3) that can identify and quantify dividing cells in tissue samples, which is a marker highly specific to mitotic figures. Other markers such as BCL-2 also contribute to tumorigenesis and may be involved in the differentiation of neuroendocrine cells. MATERIALS AND METHODS: A retrospective observational study was performed on patients undergoing surveillance for PNETs from January 2010 to May 2021. Data collection included the patients' age, sex, tumor location, tumor size in the surgical specimen, and tumor grade in FNA. The 2019 World Health Organization (WHO) classification guideline was followed to diagnose PNETs, including grade and stage. Immunohistochemical stainings for Ki-67, PHH3 and BCL-2 in PNETs were performed. RESULTS: After excluding cell blocks containing fewer than 100 tumor cells, 44 patients with EUS-FNA and surgical resection specimens were included in this study. There were 19 cases of G1 PNETs, 20 cases of G2 PNETs, and 5 cases of G3 PNETs. The grade assigned based on the Ki-67 index was higher and more sensitive than that based on the mitotic count using H&E slides in some cases of G2 and G3 PNETs. However, there was no significant difference between the mitotic count using PHH3-positive tumor cells and the Ki-67 index to grade PNETs. All grade 1 tumors (19 cases) on surgical resection specimens were correctly graded on FNA (100 % concordance rate). Within the 20 G2 PNETs, 15 cases of grade 2 on surgical resection specimens were graded correctly on FNA based on the Ki-67 index only. Five cases of grade 2 PNETs on surgical resection specimens were graded as grade 1 on FNA when using only the Ki-67 index. Three of five grade 3 tumors on surgical resection specimens were graded as grade 2 on FNA based on the Ki-67 index only. Using only FNA Ki-67 to predict PNET tumor grade, the concordance (accuracy) rate was 81.8 % in total. However, all these eight cases (5 cases of G2 PNETs and 3 cases of G3 PNETs) were graded correctly by using the Ki-67 index plus mitotic rate (using PHH3 IHC stains). Four of 18 (22.2 %) patients with PNETs were positive for BCL-2 stain. In these 4 cases positive for BCL-2 stains, 3 cases were G2 PNETs and one case was G3 PNETs. CONCLUSION: Grade and the proliferative rate in EUS-FNA can be used to predict the tumor grade in surgical resection specimens. However, when using only FNA Ki-67 to predict PNET tumor grade, about 18 % of cases were downgraded by one level. To solve the problem, immunohistochemical staining for BCL-2 and especially PHH3 would be helpful. Our results demonstrated that the mitotic count using PHH3 IHC stains not only improved the accuracy and precision of PNET grading in the surgical resection specimens, but also could reliably be used in routine scoring of mitotic figures of FNA specimens.

Concurrent Hepatoblastoma and Wilms Tumor Leading to Diagnosis of Beckwith-Wiedemann Syndrome.

Beckwith-Wiedemann syndrome (BWS) is an epigenetic overgrowth disorder and cancer predisposition syndrome caused by imprinting defects of chromosome 11p15.5-11p15.4. BWS should be considered in children with atypical presentations of embryonal tumors regardless of clinical phenotype. Risk of malignancy correlates with specific molecular subgroups of BWS making molecular subclassification important for appropriate cancer screening. We report the first case of concurrent embryonal tumors in a phenotypically normal child, leading to the diagnosis of BWS with paternal uniparental disomy and describe the molecular classification of BWS as it relates to malignancy risk, along with approach to management.

Proteomic analyses of ECM during pancreatic ductal adenocarcinoma progression reveal different contributions by tumor and stromal cells.

Pancreatic ductal adenocarcinoma (PDAC) has prominent extracellular matrix (ECM) that compromises treatments yet cannot be nonselectively disrupted without adverse consequences. ECM of PDAC, despite the recognition of its importance, has not been comprehensively studied in patients. In this study, we used quantitative mass spectrometry (MS)-based proteomics to characterize ECM proteins in normal pancreas and pancreatic intraepithelial neoplasia (PanIN)- and PDAC-bearing pancreas from both human patients and mouse genetic models, as well as chronic pancreatitis patient samples. We describe detailed changes in both abundance and complexity of matrisome proteins in the course of PDAC progression. We reveal an early up-regulated group of matrisome proteins in PanIN, which are further up-regulated in PDAC, and we uncover notable similarities in matrix changes between pancreatitis and PDAC. We further assigned cellular origins to matrisome proteins by performing MS on multiple lines of human-to-mouse xenograft tumors. We found that, although stromal cells produce over 90% of the ECM mass, elevated levels of ECM proteins derived from the tumor cells, but not those produced exclusively by stromal cells, tend to correlate with poor patient survival. Furthermore, distinct pathways were implicated in regulating expression of matrisome proteins in cancer cells and stromal cells. We suggest that, rather than global suppression of ECM production, more precise ECM manipulations, such as targeting tumor-promoting ECM proteins and their regulators in cancer cells, could be more effective therapeutically.

Endoscopic ultrasound guided fine-needle aspiration: What variables influence diagnostic yield?

BACKGROUND: Endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) plays an important role in the diagnosis of various lesions. We sought to determine factors that influence the diagnostic yield of EUS-FNA, specifically, the presence of a cytopathologist, FNA site, and the endoscopist's skill. METHODS: The data on cytopathologist's availability, duration of procedure, number of passes made, and diagnostic material for cell block (CB) preparation was collected over an 18 months period. RESULTS: 230 specimens (218 patients) were obtained from pancreas (114), lymph node (64), submucosal lesions of the gastrointestinal tract (27), liver (8), and miscellaneous (17) sites. The results were classified as informative (77.8%) and non-informative (NI) (22.2%). The NI rate was significantly high, when a cytopathologist was absent (P = .0008). As the likelihood of cytopathologist's presence increased from 35.8% to 82.9%, the CB quality increased (P < .0001). In the absence of a cytopathologist, the likelihood of NI result increased more than 2-fold (P = .03) and of an inadequate CB increased 3-fold (P < .0001). The more experienced endoscopist "C" (compared to the less experienced "A + B") was less likely to get inadequate material (40.5% vs. 66.3%) (P = .0001). CONCLUSION: The diagnostic yield of EUS-FNA is significantly related to the presence of an on-site cytopathologist and endoscopist's skill in procuring diagnostic material.

Radiology-pathology conference: primary adrenal lymphoma.

We present a case of a 62-year-old man with a history of type II diabetes mellitus who presented to our emergency department with back pain and right upper quadrant abdominal pain associated with vomiting and weight loss. A computed tomographic scan of the abdomen and pelvis demonstrated a large adrenal mass, and subsequent biopsy showed primary adrenal lymphoma.

Diagnosis of intra-abdominal and mediastinal sarcoidosis with EUS-guided FNA.

BACKGROUND: In the presence of a compatible clinical picture, the diagnosis of sarcoidosis requires pathologic confirmation of noncaseating epithelioid granuloma in affected tissues. The standard procedure of choice for most patients is a bronchoscopy with transbronchial biopsy (TBB), which has a diagnostic yield of 40% to 90%. The lowest yield with TBB is in cases that present with predominant mediastinal or intra-abdominal lymphadenopathy (LN) and minimal parenchymal lung involvement. OBJECTIVE: To study the diagnostic yield of EUS-guided FNA in diagnosing sarcoidosis with predominant LN or masses. DESIGN: Retrospective chart review. SETTING: Teaching university hospital. PATIENTS: Analysis of 21 consecutive patients with sarcoidosis and predominant mediastinal and/or intra-abdominal LN or masses who underwent EUS-guided FNA. RESULTS: EUS-guided FNA diagnosed sarcoidosis in 18 of 21 patients (86%). In 3 patients, EUS-guided FNA was either not diagnostic or inconclusive, and patients underwent mediastinoscopy with lymphadenectomy, which established the diagnosis of sarcoidosis. Seven of the 21 patients (33%) had intra-abdominal LN and/or masses, and EUS-guided FNA of the intra-abdominal pathology was diagnostic of sarcoidosis in 4 of the 7 patients (57%). Four of the 21 patients (19%) had a history of malignancy, and use of EUS-guided FNA helped in ruling out the recurrence of malignancy in 3 of the 4 patients (75%). LIMITATIONS: Mycobacterial and fungal culture was not obtained in all patients. CONCLUSIONS: EUS-guided FNA offers a practical, minimally invasive technique for the diagnosis of sarcoidosis in patients who present with predominant mediastinal and/or intra-abdominal LN or masses.

Radiology-Pathology Conference: Bilateral renal oncocytomas.

Oncocytoma is an uncommon benign, typically solitary renal tumor first reported in 1942. Renal oncocytomas are rarely multiple and/or bilateral. Accurate preoperative diagnosis and differentiation from renal carcinoma is difficult. We report the radiology and pathology of a patient with bilateral renal oncocytomas and review the literature of this rare presentation.

Detection of numerical chromosomal abnormalities in epithelial ovarian neoplasms by fluorescence in situ hybridization (FISH) and a review of the current literature.

Preliminary retrospective chromosomal analysis was performed using fluorescence in situ hybridization (FISH) with alphoid DNA probes for chromosomes 1, 3, 6, 8, 12, 17, and X. Twenty-four epithelial ovarian tumors were examined in this pilot study, including 8 borderline (LMP) serous tumors, 9 serous carcinoma, and 7 mucinous carcinoma. Hybridization signals were counted to demonstrate the frequency of aneusomy, trace chromosomal progression, and identify the predominance of chromosome copy number abnormalities that are specific to a particular histotype. The preliminary results revealed almost an equal number of mean aneusomies in serous (58.13 +/- 13%) and mucinous (64.33 +/- 10%) carcinoma, both of which were slightly higher than borderline serous tumors (50.57 +/- 17%). Hyposomies 3 and X were significantly higher in mucinous than in serous ovarian carcinomas, and lowest in borderline serous tumors (P<0.05 and P<0.01). Signal losses were a more frequent abnormality in all three histologic subtypes. Mucinous carcinomas showed a loss of chromosomes 8 (45.00 +/- 28%) and 3 (43.14 +/- 16%), in addition to a loss of chromosome X (56.29 +/- 12%). Serous carcinomas showed a gain of chromosome 1 (39.44 +/- 32%), followed by losses of chromosomes 6 (37.00 +/- 20%), 17 (36.44 +/- 19%), and 8 (36.89 +/- 19%). In borderline serous tumors, the most frequent findings were losses of chromosomes 6 (38.00 +/- 17%), 12 (36.88 +/- 17%), and 3 (36.13 +/- 21%). However, further research is necessary to substantiate these preliminary results and elucidate their clinical significance. A brief review of the literature pertaining to interphase cytogenetics in ovarian epithelial tumors is discussed also.