The Genetic Landscape of Primary Breast Marginal Zone Lymphoma Identifies a Mutational-driven Disease With Similarities to Ocular Adnexal Lymphoma.

Extranodal marginal zone lymphomas (eMZL) can occur in any organ and site of the body. Recent research has shown that they differ from organ to organ in terms of their mutational profile. In this study, we investigated a cohort of primary breast marginal zone lymphomas (PBMZL) to get a better insight into their morphologic and molecular profile. A cohort of 15 cases (14 female and 1 male) was characterized by immunohistochemistry (IHC) for 19 markers, fluorescence in situ hybridization (FISH), and high throughput sequencing (HTS) using a lymphoma panel comprising 172 genes. In addition, PCR for the specific detection of Borrelia spp. and metagenomics whole genome sequencing were performed for infectious agent profiling. Follicular colonization was observed in most cases, while lymphoepithelial lesions, though seen in many cases, were not striking. All 15 cases were negative for CD5, CD11c, and CD21 and positive for BCL2 and pan B-cell markers. There were no cases with BCL2, BCL10, IRF4, MALT1, or MYC translocation; only 1 had a BCL6 rearrangement. HTS highlighted TNFAIP3 (n=4), KMT2D (n=2), and SPEN (n=2) as the most frequently mutated genes. There were no Borrelia spp., and no other pathogens detected in our cohort. One patient had a clinical history of erythema chronicum migrans affecting the same breast. PBMZL is a mutation-driven disease rather than fusion-driven. It exhibits mutations in genes encoding components affecting the NF-κB pathway, chromatin modifier-encoding genes, and NOTCH pathway-related genes. Its mutational profile shares similarities with ocular adnexal and nodal MZL.

Treatment of vulvar cancer recurrence with electrochemotherapy: a case-control study.

BACKGROUND: Electrochemotherapy (ECT) is a combined treatment method based on electroporation and simultaneous chemotherapy. In cases where radiotherapy has previously been used, surgery is often the only treatment option for vulvar cancer recurrence with potential resection of clitoris, vagina, urethra or anal sphincter. The unique advantage of ECT is its selectivity for cancer cells while sparing the surrounding healthy tissue. The aim of the study was to compare the ECT treatment of vulvar cancer recurrence for non-palliative purposes with surgical treatment. MATERIALS AND METHODS: Eleven patients with single vulvar cancer recurrence were treated with ECT and followed up for 12 months. As a control group, 15 patients with single vulvar cancer recurrence were treated with wide local excision. The following data were collected, analyzed and compared: Age, body mass index, comorbidities, histological type, location and size of vulvar cancer recurrence, treatment history, details of procedures and hospital stay. RESULTS: The probability curves for local tumor control did not differ between the ECT group and the surgical group (p = 0.694). The mean hospital stay and the mean duration of procedure were statistically significantly shorter in the ECT group (p < 0.001). There were no statistically significant differences between the ECT and surgical groups in terms of mean body mass index, associated diseases, previous treatments, presence of lichen sclerosus, p16 status, gradus, anatomical site of the tumor, and type of anesthesia. CONCLUSION: In this case-control study, treatment of vulvar cancer recurrence with ECT for non-palliative purposes was comparable to surgical treatment in terms of effectiveness. The results need to be confirmed in larger randomized trials.

Detection performance and prognostic value of initial bone marrow involvement in diffuse large B-cell lymphoma: a single centre 18F-FDG PET/CT and bone marrow biopsy evaluation study.

BACKGROUND: Detection of bone marrow involvement (BMI) in diffuse large B-cell lymphoma (DLBCL) typically relies on invasive bone marrow biopsy (BMB) that faces procedure limitations, while 18F-FDG PET/CT imaging offers a noninvasive alternative. The present study assesses the performance of 18F-FDG PET/CT in DLBCL BMI detection, its agreement with BMB, and the impact of BMI on survival outcomes. PATIENTS AND METHODS: This retrospective study analyzes baseline 18F-FDG PET/CT and BMB findings in145 stage II-IV DLBCL patients, evaluating both performance of the two diagnostic procedures and the impact of BMI on survival. RESULTS: DLBCL BMI was detected in 38 patients (26.2%) using PET/CT and in 18 patients (12.4%) using BMB. Concordant results were seen in 79.3% of patients, with 20.7% showing discordant results. Combining PET/CT and BMB data, we identified 29.7% of patients with BMI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT for detecting DLBCL BMI were 88.4%, 100%, 100%, 95.3%, and 96.5%, respectively, while BMB showed lower sensitivity (41.9%) and NPV (46.8%). The median overall survival (OS) was not reached in any gender subgroup, with 5-year OS rates of 82% (total), 84% (female), and 80% (male) (p = 0.461), while different International Prognostic Index (IPI) groups exhibited varied 5-year OS rates: 94% for low risk (LR), 91% for low-intermediate risk (LIR), 84% for high-intermediate risk (HIR), and 65% for high risk (HR) (p = 0.0027). Bone marrow involvement did not impact OS significantly (p = 0.979). CONCLUSIONS: 18F-FDG PET/CT demonstrated superior diagnostic accuracy compared to BMB. While other studies reported poorer overall and BMI 5-year OS in DLBCL, our findings demonstrated favourable survival data.

The prognostic significance of programmed cell death protein 1 and its ligand on lymphoma cells and tumor-immune cells in diffuse large B-cell lymphoma, not otherwise specified.

BACKGROUND: Diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) is the most common type non-Hodgkin's lymphoma, where the treatment of relapsed/refractory cases is the major challenge. Programmed cell death protein 1 (PD-1) and its ligand PD-L1 play a crucial role in the negative regulation of the immune response against the disease. The aim of the study was to analyze the expression of PD-1 and PD-L1 on lymphoma cells (LCs) and tumor-immune cells (TICs) and to investigate their correlation with outcome. PATIENTS AND METHODS: Samples from 283 patients diagnosed with DLBCL, NOS (both germinal center B cell like [GCB] and non-GCB subtypes) were included in the study. Expression of PD-1 and PD-L1 was determined using double immunohistochemical staining (D-IHC) for PD-1/PAX5 and PD-L1/PAX5 on tissue microarrays. LCs were highlighted by D-IHC to obtain more accurate results. Clinical data and histologic diagnoses were obtained from electronic data records. We correlated clinical characteristics, and PD-1 and PD-L1 expression on LCs and TICs with progression-free survival (PFS) and overall survival (OS). RESULTS: Expression of PD-1 on TICs was observed in 38.4% and on LCs in 8.8% of cases, while PD-L1 was expressed on TICs in 46.8% and on LCs in 6.5% of cases. PD-L1 expression on LCs was more frequent in non-GCB subtype (p = 0.047). In addition, patients with PD-L1 expression on LCs had significantly shorter PFS (p = 0.015), and the expression retained significant in the multivariate model (p = 0.034). CONCLUSIONS: PD-L1 was more frequently expressed in LCs of the non-GCB subtype. Additionally, PD-L1 in LCs may predict shorter PFS time. D-IHC staining for PD-L1/PAX5 is a feasible method to assess PD-L1 expression on LCs of DLBCL, NOS patients and can be used to identify patients who may benefit from targeted immunotherapy with checkpoint inhibitors.

Do Double-Expressor High-Grade B-Cell Lymphomas Really Need Intensified Treatment? A Report from the Real-Life Series of High-Grade B-Cell Lymphomas Treated with Different Therapeutic Protocols at the Institute of Oncology Ljubljana.

High-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements are known for their aggressive clinical course and so are the ones with MYC and BCL2 protein overexpression. The optimal therapy for these lymphomas remains to be elucidated. A retrospective analysis of all diffuse large B-cell lymphomas and high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements diagnosed between 2017 and 2021 at the Institute of Oncology Ljubljana, Slovenia, has been performed. Only patients with double-expressor lymphoma (DEL), double-hit lymphoma (DHL), or triple-hit lymphoma (THL) were included. Demographic and clinical parameters were assessed, as well as progression-free survival (PFS) and overall survival (OS). In total, 161 cases out of 309 (161/309; 52,1%) were classified as DEL. Sixteen patients had DHL, MYC/BCL2 rearrangement was observed in eleven patients, and MYC/BCL6 rearrangement was observed in five patients. Five patients were diagnosed with THL. Out of 154 patients (according to inclusion/exclusion criteria) included in further evaluation, one-hundred and thirty-five patients had double-expressor lymphoma (DEL), sixteen patients had DHL, and three patients had THL. In total, 169 patients were treated with R-CHOP, 10 with R-CHOP and intermediate-dose methotrexate, 19 with R-DA-EPOCH, and 16 with other regimens. The median follow-up was 22 months. The 5-year OS for the whole DEL group was 57.1% (95% CI 45.9-68.3%) and the 5-year PFS was 76.5% (95% CI 72.6-80.4%). The log-rank test disclosed no differences in survival between treatment groups (p = 0.712) while the high-risk international prognostic index (IPI) carried a significantly higher risk of death (HR 7.68, 95% CI 2.32-25.49, p = 0.001). The 5-year OS for DHL patients was 32.4% (95% CI 16.6-48.2%) while all three TH patients were deceased or lost to follow-up. Our analyses of real-life data disclose that the R-CHOP protocol with CNS prophylaxis is a successful and curative treatment for a substantial proportion of DEL patients.

The prognostic significance of tumor-immune microenvironment in ascites of patients with high-grade serous carcinoma.

BACKGROUND: High-grade serous carcinoma (HGSC) is often associated with ascites at presentation. Our objective was to quantify immune cells (ICs) in ascites prior to any treatment was given and evaluate their impact on progression-free survival (PFS) and overall survival (OS). PATIENTS AND METHODS: Forty-seven patients with primary HGSC and ascites were included. Flow-cytometric analysis was performed to detect percentages of CD3+ T cells (CD4+, CD8+, Tregs, and NKT cells), B cells, NK cells (CD56brightCD16- and CD56dimCD16+ subsets), macrophages and dendritic cells (DCs). Furthermore, CD103 expression was analyzed on T cells and their subsets, while PD-1 and PD-L1 expression on all ICs. Cut-off of low and high percentages of ICs was determined by the median of variables, and correlation with PFS and OS was calculated. RESULTS: CD3+ cells were the predominant ICs (median 51%), while the presence of other ICs was much lower (median ≤10%). CD103+ expression was mostly present on CD8+, and not CD4+ cells. PD-1 was mainly expressed on CD3+ T cells (median 20%), lower expression was observed on other ICs (median ≤10%). PD-L1 expression was not detected. High percentages of CD103+CD3+ T cells, PD-1+ Tregs, CD56brightCD16- NK cells, and DCs correlated with prolonged PFS and OS, while high percentages of CD8+ cells, macrophages, and PD-1+CD56brightCD16- NK cells, along with low percentages of CD4+ cells, correlated with better OS only. DCs were the only independent prognostic marker among all ICs. CONCLUSIONS: Our results highlight the potential of ascites tumor-immune microenvironment to provide additional prognostic information for HGSC patients. However, a larger patient cohort and longer follow-up are needed to confirm our findings.

Clear Cell Carcinoma Arising in Low-Grade Mullerian Adenosarcoma: First Reported Case with Insight into Molecular Profile.

Uterine adenosarcoma (AS) is a rare biphasic neoplasm composed of a malignant, usually low-grade stromal component and benign epithelial component, usually endometrioid. Pathogenesis is unknown; some cases are undoubtably associated with tamoxifen use. Endometrial clear cell carcinoma (CCC) is an aggressive subtype of endometrial cancer, accounting for less than 10% of all uterine carcinomas. The etiology is unknown but can rarely be associated with Lynch syndrome and tamoxifen administration. The development of a composite neoplasm consisting of adenocarcinoma in AS is extremely rare. Endometrioid carcinoma typically represents the epithelial component of the composite tumor. Here we present the very first case of composite tumor, namely, AS with CCC in which next-generation sequencing was performed. Patient was an 85-year-old woman treated with tamoxifen for 5 years. To better understand the pathobiology of two tumors, a targeted genomic analysis of both components was performed. We found seven identical somatic variants in the samples of both tumors, indicating that the tumors have a high probability of having the same origin. Dual amplification of CDK4 and MDM2 was the most likely primary cause of tumor formation, but also one driver variant in the DHX15 gene that was present in both tumor components, suggesting that DHX15 may play an important role in the initiation and development of sarcoma and carcinoma. The patient is followed by regular clinical controls and is alive without signs of disease recurrence 18 months after surgery.

Morphological and Immunocytochemical Characterization of Tumor Spheroids in Ascites from High-Grade Serous Carcinoma.

Tumor spheroids in the ascites of high-grade serous carcinoma (HGSC) are poorly described. Our objective was to describe their morphological features, cellular composition, PD-1 and PD-L1 expression, and survival correlation of these parameters. The density and size of spheroids were assessed in Giemsa-stained smears; the cell composition of spheroids, including tumor cells, immune cells, capillaries, and myofibroblasts, as well as PD-1 and PD-L1 expression on tumor and immune cells was assessed in immunocytochemically stained cell block sections. Forty-seven patients with primary HGSC and malignant ascites were included. A cut-off value for a spheroid density of 10% was established, which significantly predicted overall survival. However, spheroid size did not correlate with survival outcomes. Spheroids were primarily composed of tumor cells, but the presence of lymphocytes and macrophages was also confirmed. Moreover, capillaries were present in the spheroids of three patients, but the presence of myofibroblasts was not confirmed. PD-1 was expressed on lymphocytes but not on tumor cells. PD-L1 expression was seen on both tumor and immune cells, assessed by 22C3 and SP263 antibody clones but not by the SP142 clone. Our results highlight the potential of routine cytopathological techniques to analyze spheroids in HGSC ascites as a valuable tool to investigate their potential as prognostic markers.

Axillary ultrasound for predicting response to neoadjuvant treatment in breast cancer patients-a single institution experience.

BACKGROUND: In node-positive breast cancer patients at diagnosis (cN +) that render node-negative after neoadjuvant systemic treatment (NAST), axillary lymph node dissection (ALND) can be avoided in selected cases. Axillary ultrasound (AUS) is most often used for re-staging after NAST. We aimed to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of AUS after NAST for predicting nodal response at the Institute of Oncology, Ljubljana. METHODS: Biopsy-confirmed cN + patients consecutively diagnosed at our institution between 2008 and 2021, who received NAST, followed by surgery were identified retrospectively. Only patients that underwent AUS after NAST were included. AUS results were compared to definite nodal histopathology results. We calculated sensitivity, specificity, PPV and NPV of AUS. We also calculated the proportion of patients with false-positive AUS that results in surgical overtreatment (unnecessary ALND). RESULTS: We identified 437 cN + patients. In 244 (55.8%) AUS after NAST was performed. Among those, 42/244 (17.2%) were triple negative (TN), 78/244 (32.0%) Her-2 positive (Her-2 +), and 124/244 (50,8%) luminal Her-2 negative cancers. AUS was negative in 179/244 (73.4%), suspicious/positive in 65/244 (26.6%) (11/42 (26.2%) TN, 19/78 (24.4%) Her-2 + , and 35/124 (28.2%) luminal Her-2 negative cancers). On definite histopathology, nodal complete response (pCR) was observed in 89/244 (36.5%) (19/42 (45.2%) TN, 55/78 (70.5%) Her-2 + , and 15/124 (12.1%) luminal Her-2 negative cancers). Among patients with suspicious/positive AUS, pCR was observed in 20/65 (30.8%) (6/11 (54.5%) TN, 13/19 (68.4%) Her-2 + and 1/35 (2.9%) luminal Her-2 negative cancers). Sensitivity was 29.0%, specificity 77,5%, PPV 69.2%, NPV 38.5%. Specificity and PPV in TN was 68.4% and 45.4%, in Her-2 + 76.4% and 31.6%, in luminal Her-2 negative 93,3% and 97,1%, respectively. CONCLUSION: In approximately half of the patients, AUS falsely predicts nodal response after NAST and may lead to overtreatment in 30% of the cases (ALND). However, AUS has to be interpreted in context with tumor subtype. In luminal Her-2 negative cancers, it has a high PPV and is therefore useful.

Absence of post-treatment changes in sentinel lymph nodes does not translate into increased regional recurrence rate in initially node-positive breast cancer patients.

PURPOSE: To determine whether the absence of post-treatment changes in the negative sentinel lymph nodes (SLN) in the neoadjuvant setting for biopsy-proven cN + disease results in an increased regional recurrence (RR) rate in patients after SLN biopsy (SLNB) only. METHODS: Breast cancer patients with biopsy-proven cN + disease who converted to node-negative disease after neoadjuvant systemic treatment (NAST) and underwent SLNB only were included. Retrospective analysis was performed for patients diagnosed between 2008 and 2021. Pathohistological specimens were reviewed for the presence of post-treatment changes in the SLNs. Patients with negative SLNs (ypN0) were divided into two groups: (i) with post-treatment changes, (ii) without post-treatment changes. Patients' characteristics were compared between groups. Crude RR rates were compared using the log-rank test. Recurrence-free (RFS) and overall survival (OS) for the entire cohort were calculated using Kaplan-Meier. RESULTS: Of 437 patients with cN + disease, 95 underwent SLNB only. 82 were ypN0, 57 with post-treatment changes (group 1), 25 without post-treatment changes (group 2). During the median follow-up of 37 months (range 6-148), 1 isolated regional recurrence occurred in group 2 (RR rate 0% for group 1 vs. 4% for group 2, p = 0.149). There were no differences in 3-year RFS and OS between groups. CONCLUSION: Absent post-treatment changes in negative SLNs for biopsy-proven cN + disease that covert to node-negative after NAST did not result in increased regional recurrence rates in our cohort. Multidisciplinary input is essential to determine whether additional treatment is needed in these patients.

Histologic changes of porcine portal vein anastomosis after electrochemotherapy with bleomycin.

Electrochemotherapy (ECT1) is used for treatment of unresectable abdominal malignancies. This study aims to show that ECT of porcine portal vein anastomosis is safe and feasible in order to extend the indications for margin attenuation after resection of locally advanced pancreatic carcinoma. No marked differences were found between the control group and ECT treated groups. Electroporation thus caused irreversible damage to the vascular smooth muscle cells in tunica media that could bedue to the narrow irreversible electroporation zone that may occur near the electrodes, or due to vasa vasorum thrombosis in the tunica externa. Based on the absence of vascular complications, and similar histological changes in lienal veinanastomosis, we can conclude that ECT of portal vein anastomosis is safe and feasible.

Electrochemotherapy of Melanoma Cutaneous Metastases in Organ Transplant Recipients: A Systematic Review of Preclinical and Clinical Studies.

Cutaneous melanoma is a highly aggressive form of skin cancer. The development of immune checkpoint inhibitors (ICIs) has revolutionized the management of advanced melanoma, led to durable responses, and improved overall survival. However, the success of ICIs in melanoma treatment is influenced by the tumor microenvironment (TME) which plays a critical role in regulating the immune response to the tumor. Understanding the mechanisms underlying this interaction is crucial to optimizing the efficiency of ICIs. Electrochemotherapy (ECT) has been shown to enhance the efficacy of ICIs in melanoma treatment by inducing tumor cell death and facilitating the release of tumor antigens which can subsequently be recognized and targeted by the immune system. Moreover, ECT has been reported to modulate the TME, leading to increased infiltration of immune cells and a more favorable immunological profile. In this review, we summarize the available knowledge of changes in TME after ECT of melanoma cutaneous metastasis and highlight the differences in tumor-infiltrating immune cells between immunocompetent and immunosuppressed organisms. In addition, we showed that ECT can be an effective and safe procedure for organ transplant recipients. Furthermore, repeated ECT may enhance immune activation and probably induce a bystander effect by trained immunity.

CD56-positive diffuse large B-cell lymphoma: comprehensive analysis of clinical, pathological, and molecular characteristics with literature review.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma. The expression of CD56 in DLBCL is highly unusual. Little is known about its incidence and clinical importance. So far, no genetic profiling was performed in CD56 positive DLBCL. PATIENTS AND METHODS: Tissue microarrays have been constructed, sectioned, and stained by H&E and immunohistochemistry for 229 patients with DLBCL diagnosed 2008-2017. For CD56 positive cases, clinical data was collected including age at diagnosis, stage of the disease, International Prognostic Index (IPI) score, treatment scheme and number of chemotherapy cycles, radiation therapy, treatment outcome, and possible relapse of the disease. Overall survival (OS) and progression-free survival (PFS) were calculated. For four patients, RNA was extracted and targeted RNA (cDNA) sequencing of 125 genes was performed with the Archer FusionPlex Lymphoma kit. RESULTS: CD56 expression was found in 7 cases (3%). The intensity of expression varied from weak to moderate focal, to very intensive and diffuse. All patients had de novo DLBCL. The median age at the time of diagnosis was 54.5 years. Five of them were women and 2 males. According to the Hans algorithm, 6 patients had the germinal centre B cells (GBC) type and one non-GBC (activated B-cell [ABC]) type, double expressor. Genetic profiling of four patients according to Schmitz's classification showed that 1 case was of the BN2 subtype, 1 of EZB subtype, 2 were unclassified. The six treated patients reached a complete response and did not experience progression of the disease during the median follow-up period of 80.5 months. CONCLUSIONS: We report on one of the largest series of CD56+DLBCL with detailed clinicopathological data and for the first time described genetical findings in a limited number of patients. Our results show that CD56 expression is rare, but seems to be present in prognostic favourable subtypes of DLBCL not otherwise specified (NOS) as tested by immunohistochemical or genetic profiling.

Treatment of vulvar cancer recurrences with electrochemotherapy - a detailed analysis of possible causes for unsuccessful treatment.

BACKGROUND: Electrochemotherapy has good local effectiveness in the treatment of vulvar cancer. Most studies have reported the safety and effectiveness of electrochemotherapy for palliative treatment of gynecological cancers and mostly vulvar squamous cell carcinoma. Some tumors, however, fail to respond to electrochemotherapy. The biological features/determinants for the nonresponsiveness are not determined yet. PATIENT AND METHODS: A recurrence of vulvar squamous cell carcinoma was treated by electrochemotherapy using intravenous administration of bleomycin. The treatment was performed by hexagonal electrodes according to standard operating procedures. We analyzed the factors that could determine nonresponsiveness to electrochemotherapy. RESULTS: Based on the presented case of nonresponsive vulvar recurrence to electrochemotherapy, we hypothesize that the vasculature of the tumors prior to treatment may predict the response to electrochemotherapy. The histological analysis showed minimal presence of blood vessels in the tumor. Thus, low perfusion may reduce drug delivery and lead to a lower response rate because of the minor antitumor effectiveness of vascular disruption. In this case, no immune response in the tumor was elicited by electrochemotherapy. CONCLUSIONS: In this case, of nonresponsive vulvar recurrence treated by electrochemotherapy, we analyzed possible factors that could predict treatment failure. Based on histological analysis, low vascularization of the tumor was observed, which hampered drug delivery and distribution and resulted in no vascular disrupting action of electro-chemotherapy. All these factors could contribute to ineffective treatment with electrochemotherapy.

Cytokeratin and CD56 aberrant co-expression in diffuse large B-cell lymphoma, NOS misinterpreted as metastatic neuroendocrine carcinoma by FNAC.

Aberrant expression of epithelial and neuroendocrine markers is rare in diffuse large B-cell lymphoma (DLBCL) and can lead to erroneous diagnosis with inappropriate treatment. This case report describes a case of DLBCL with a co-expression of cytokeratins and CD56 that was misdiagnosed as metastatic neuroendocrine carcinoma.

Numerical mesoscale tissue model of electrochemotherapy in liver based on histological findings.

Electrochemotherapy (ECT) and irreversible electroporation (IRE) are being investigated for treatment of hepatic tumours. The liver is a highly heterogeneous organ, permeated with a network of macro- and microvasculature, biliary tracts and connective tissue. The success of ECT and IRE depends on sufficient electric field established in whole target tissue; therefore, tissue heterogeneity may affect the treatment outcome. In this study, we investigate electroporation in the liver using a numerical mesoscale tissue model. We numerically reconstructed four ECT experiments in healthy porcine liver and computed the electric field distribution using our treatment planning framework. We compared the computed results with histopathological changes identified on microscopic images after treatment. The mean electric field threshold that best fitted the zone of coagulation necrosis was 1225 V/cm, while the mean threshold that best fitted the zone of partially damaged liver parenchyma attributed to IRE was 805 V/cm. We evaluated how the liver macro- and microstructures affect the electric field distribution. Our results show that the liver microstructure does not significantly affect the electric field distribution on the level needed for treatment planning. However, major hepatic vessels and portal spaces significantly affect the electric field distribution, and should be considered when planning treatments.

NUT Carcinoma: A Clinical, Morphological and Immunohistochemical Mimicker-The Role of RNA Sequencing in the Diagnostic Procedure.

Background: NUT carcinoma is a highly aggressive and rare subset of squamous cell carcinoma with grim prognosis. It is under-recognized by both pathologists and oncologists. Recognition is challenging due to its rareness and the fact that its clinical and laboratory features as well as morphological and immunohistochemical characteristics may mimic other malignancies. Case presentation: An interesting case of NUT carcinoma in a 47-year-old male with a large tumor mass in the inferior part of the mediastinum and left lung and increased levels of serum alpha fetoprotein (AFP) is described. Immunohistochemical analysis of both the primary tumor in a bronchoscopy specimen and an excisional biopsy of a subcutaneous metastasis showed positivity for AFP and leukocyte common antigen (LCA) that were misleading and resulted in diagnostic pitfalls of mediastinal germ cell tumor (clinically) and hematolymphoid neoplasm (pathologic report). Immunohistochemical demonstration of NUT protein expression revealed the proper diagnosis, which was further confirmed by RNA sequencing revealing a BRD4-NUTM1 gene fusion.Conclusions: Since NUT carcinoma can show a wide spectrum of histological and immunophenotypic features and can clinically mimic other tumors, use of RNA sequencing with identification of specific NUTM1 fusion partner could be crucial when there are discrepant clinical and histopathological findings. As well, since the category of so-called NUTM1-rearranged neoplasms is rapidly expanding, identification of NUTM1 fusion partner may be essential for the appropriate clinical management.

A Systematic Review about Imaging and Histopathological Findings for Detecting and Evaluating Electroporation Based Treatments Response.

BACKGROUND: Imaging methods and the most appropriate criteria to be used for detecting and evaluating response to oncological treatments depend on the pathology and anatomical site to be treated and on the treatment to be performed. This document provides a general overview of the main imaging and histopathological findings of electroporation-based treatments (Electrochemotherapy-ECT and Irreversible electroporation-IRE) compared to thermal approach, such as radiofrequency ablation (RFA), in deep-seated cancers with a particular attention to pancreatic and liver cancer. METHODS: Numerous electronic datasets were examined: PubMed, Scopus, Web of Science and Google Scholar. The research covered the years from January 1990 to April 2021. All titles and abstracts were analyzed. The inclusion criteria were the following: studies that report imaging or histopathological findings after ablative thermal and not thermal loco-regional treatments (ECT, IRE, RFA) in deep-seated cancers including pancreatic and liver cancer and articles published in the English language. Exclusion criteria were unavailability of full text and congress abstracts or posters and different topic respect to inclusion criteria. RESULTS: 558 potentially relevant references through electronic searches were identified. A total of 38 articles met the inclusion criteria: 20 studies report imaging findings after RFA or ECT or IRE in pancreatic and liver cancer; 17 studies report histopathological findings after RFA or ECT or IRE; 1 study reports both imaging and histopathological findings after RFA or ECT or IRE. CONCLUSIONS: Imaging features are related to the type of therapy administrated, to the timing of re-assessment post therapy and to the imaging technique being used to observe the effects. Histological findings after both ECT and IRE show that the treated area becomes necrotic and encapsulated in fibrous tissue, suggesting that the size of the treated lesion cannot be measured as an endpoint to detect response. Moreover, histology frequently reported signs of apoptosis and reduced vital tissue, implying that imaging criteria, which take into account the viability and not the size of the lesion, are more appropriate to evaluate response to treatment.

Safety and Feasibility of Electrochemotherapy of the Pancreas in a Porcine Model.

OBJECTIVES: The use of thermal ablative therapies in the pancreatic tumors is limited because of the risk of the vessel injury and potential pancreatitis or fistula formation. Electrochemotherapy (ECT) is an ablative therapy with an established role in the treatment of cutaneous and liver tumors. This study was designed to evaluate the safety and feasibility of ECT of the pancreas in a porcine survival model. METHODS: In the first group, 4 animals underwent computed tomography (CT)-guided percutaneous ECT with bleomycin of the pancreatic tail. In the second group (4 animals), the intraoperative ECT with bleomycin of pancreatic tail and head was performed. Animals were followed for 7 days and then killed. Clinical parameters, CT imaging, laboratory, and histologic analysis were performed. RESULTS: All pigs survived the ECT procedure and none of them developed clinical signs of acute pancreatitis or related complications. There were no signs of acute pancreatitis or damage to the large vessels present in the follow-up CT scans. No significant change in laboratory parameters was obtained after procedure. CONCLUSIONS: This study shows that ECT with bleomycin is feasible and safe in the pancreatic parenchyma. Clinical studies are needed to evaluate the efficacy of ECT in pancreatic cancer.

Intraoperative electrochemotherapy of colorectal liver metastases: A prospective phase II study.

BACKGROUND AND OBJECTIVES: A previous pilot study proved the feasibility, safety and efficacy of electrochemotherapy in the treatment of colorectal liver metastases. The aim of this study was to evaluate long-term effectiveness and safety of electrochemotherapy in the treatment of unresectable colorectal liver metastases. PATIENTS AND METHODS: In this prospective phase II study, patients with metachronous colorectal liver metastases were included. In all patients, at least one metastasis was unresectable due to its central location or a too-small future remnant liver volume. Patients were treated by electrochemotherapy using intravenously administered bleomycin during open surgery. Treated were 84 metastases in 39 patients. Local tumor control, progression-free survival and overall survival were evaluated. RESULTS: The objective response was 75% (63% CR, 12% PR). The median duration of the response was 20.8 months for metastases in CR and 9.8 months for metastases in PR. The therapy was significantly more effective for metastases smaller than 3 cm in diameter than for larger ones. There was no difference in response according to the metastatic location, i.e., metastases in central vs. peripheral locations. Progression-free survival was better in patients who responded well to electrochemotherapy compared to those metastases that had a partial response or progressive disease. However, there was no difference in overall survival, with a median of 29.0 months. CONCLUSIONS: Electrochemotherapy has proven to be safe and effective in the treatment of colorectal liver metastases, with a durable response. It provides local tumor control that enables patients with unresectable metastases to receive further treatments.