Advancing the PD-L1 CPS test in metastatic TNBC: Insights from pathologists and findings from a nationwide survey.

Pembrolizumab has received approval as a first-line treatment for unresectable/metastatic triple-negative breast cancer (mTNBC) with a PD-L1 combined positive score (CPS) of ≥ 10. However, assessing CPS in mTNBC poses challenges. Firstly, it represents a novel analysis for breast pathologists. Secondly, the heterogeneity of PD-L1 expression in mTNBC further complicates the assessment. Lastly, the lack of standardized assays and staining platforms adds to the complexity. In KEYNOTE trials, PD-L1 expression was evaluated using the IHC 22C3 pharmDx kit as a companion diagnostic test. However, both the 22C3 pharmDx and VENTANA PD-L1 (SP263) assays are validated for CPS assessment. Consequently, assay-platform choice, staining conditions, and scoring methods can significantly impact the testing outcomes. This consensus paper aims to discuss the intricacies of PD-L1 CPS testing in mTNBC and provide practical recommendations for pathologists. Additionally, we present findings from a nationwide Italian survey elucidating the state-of-the-art in PD-L1 CPS testing in mTNBC.

Mast Cell Leukemia: An Update with a Practical Review.

Mast cell leukemia (MCL) is the leukemic form of SM with at least 20% mostly immature mast cells on bone marrow aspirate. MCL may develop de novo, in the absence of a prior SM, or it may represent a progression from a previous SM. MCL may be sub-divided into the more frequent, aggressive acute form with signs of organ damage (C-findings) and the chronic form lacking C-findings and presenting a more stable course, although over time, progression to acute MCL is common. The 2022 WHO subtype of MCL with an associated hematological neoplasm was renamed MCL with an associated myeloid neoplasm in the 2022 International Consensus Classification (ICC). The relevance of the distinction between the leukemic and aleukemic forms based on the percentage of circulating mast cells is a matter of debate. The current knowledge on MCL is restricted mainly to single reports or case series with a limited number of larger studies. Our aim is to provide a comprehensive overview of this rare disease in terms of clinical manifestations, morphology, phenotype, molecular characteristics, differential diagnosis, outcome and treatment. A general overview on mastocytosis is also included.

Therapeutic activation of G protein-coupled estrogen receptor 1 in Waldenström Macroglobulinemia.

Activating G protein-coupled estrogen receptor 1 (GPER1) is an attractive therapeutic strategy for treating a variety of human diseases including cancer. Here, we show that GPER1 is significantly upregulated in tumor cells from different cohorts of Waldenström Macroglobulinemia (WM) patients compared to normal B cells. Using the clinically applicable GPER1-selective small-molecule agonist G-1 (also named Tespria), we found that pharmacological activation of GPER1 leads to G2/M cell cycle arrest and apoptosis both in vitro and in vivo in animal models, even in the context of the protective bone marrow milieu. Activation of GPER1 triggered the TP53 pathway, which remains actionable during WM progression. Thus, this study identifies a novel therapeutic target in WM and paves the way for the clinical development of the GPER1 agonist G-1.

A Prognostic and Carboplatin Response Predictive Model in Ovarian Cancer: A Mono-Institutional Retrospective Study Based on Clinics and Pharmacogenomics.

Carboplatin is the cornerstone of ovarian cancer (OC) treatment, while platinum-response, dependent on interindividual variability, is the major prognostic factor for long-term outcomes. This retrospective study was focused on explorative search of genetic polymorphisms in the Absorption, Distribution, Metabolism, Excretion (ADME) genes for the identification of biomarkers prognostic/predictive of platinum-response in OC patients. Ninety-two advanced OC patients treated with carboplatin-based therapy were enrolled at our institution. Of these, we showed that 72% of patients were platinum-sensitive, with a significant benefit in terms of OS (p = 0.001). We identified an inflammatory-score with a longer OS in patients with lower scores as compared to patients with the maximum score (p = 0.001). Thirty-two patients were genotyped for 1931 single nucleotide polymorphisms (SNPs) and five copy number variations (CNVs) by the DMET Plus array platform. Among prognostic polymorphisms, we found a potential role of UGT2A1 both as a predictor of platinum-response (p = 0.01) and as prognostic of survival (p = 0.05). Finally, we identified 24 SNPs related to OS. UGT2A1 correlates to an "inflammatory-score" and retains a potential prognostic role in advanced OC. These data provide a proof of concept that warrants further validation in follow-up studies for the definition of novel biomarkers in this aggressive disease.

Successful Vaginal Delivery after Induction of Labour in a Patient Treated for Non-Hodgkin's Lymphoma of the Cervix: A Case Report and Literature Review.

OBJECTIVE: Primary non-Hodgkin's lymphomas of the cervix are rare; they represent about 1% of all cases. There are no available guidelines regarding the safest mode of delivery after treatment and resolution of a cervical lymphoma. Case Report. We report the first case of a successful vaginal delivery after induction of labour in a woman recovered from a primary large B-cell lymphoma of the cervix and a literature review. CONCLUSION: In carefully selected patients with fully treated non-Hodgkin's lymphoma of the cervix with no residual disease, induction of labour via prostaglandins pessary may be a safe option if indicated.

Autoimmune colitis and neutropenia in adjuvant anti-PD-1 therapy for malignant melanoma: efficacy of Vedolizumab, a case report.

Immune checkpoint inhibitors (ICIs) represent an important advance in the adjuvant treatment of patients with high-risk melanoma. Although the safety profile of anti-programmed cell death protein-1 (PD-1) is fairly acceptable, different immune-related adverse events (irAEs) are described. Herein we report for the first time a notably multidisciplinary combined approach on a malignant melanoma (MM) patient treated with anti-PD-1 antibody in adjuvant setting. In this novel approach, corticosteroid-refractory immune-mediated colitis (IMC) was effectively treated with Vedolizumab, a selective blockade of the α4ß7 integrin and corticosteroids were successfully administered for autoimmune neutropenia. Notably, our patient also express HLA-B*35, a potential biomarker for predicting a genetic basis of autoimmune susceptibility. Our experience offers a possible future perspective about the use of Vedolizumab together with immunotherapy in a strategic early approach for high-risk patients genotyped for HLA.

Thyroid Warthin-Like Cancer Concurrent With Multiple Sclerosis: A Case Report.

Warthin like-papillary thyroid cancer (WL-PTC) is a rare malignancy; it is difficult to distinguish preoperatively a WLPTC from a classic PTC. Often it is associated with Hashimoto thyroiditis (HT) that determines a better prognosis with a very low probability of recurrence. The case concerns a 43-year-old female with a single thyroid nodule suspected for cancer; and she had multiple sclerosis (MS) from the age of 19. Thyroid hormone levels were normal such as thyroid antibodies. Total thyroidectomy with lymphadenectomy of central compartment was performed. Histological examination revealed a Warthin like-PTC without Hashimoto thyroiditis. The mechanisms involved in pathogenesis of thyroid cancer in patients with autoimmune disease are not completely clear. We hypothesized that not only a local autoimmune response, such as HT, could contribute to the determination of this type of cancer but also a systemic autoimmune disease such as MS.

Clinical features of ProMisE groups identify different phenotypes of patients with endometrial cancer.

BACKGROUND: The Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) groups has identified four molecular prognostic groups of endometrial cancer (EC): POLE-mutated (POLE-mt), mismatch repair-deficient (MMR-d), p53-abnormal (p53-abn), p53-wild-type (p53-wt). These groups might have different pathogenesis and risk factors, and might occur in different phenotypes of patients. However, these data are still lacking. OBJECTIVE: To provide a clinical characterization of the ProMisE groups of EC. METHODS: A systematic review and meta-analysis was performed by searching seven electronic databases from their inception to December 2020, for all studies reporting clinical characteristics of EC patients in each ProMisE group. Pooled means of age and BMI and pooled prevalence of FIGO stage I and adjuvant treatment in each ProMisE group were calculated. RESULTS: Six studies with 1, 879 women were included in the systematic review. Pooled means (with standard error) and prevalence values were: in the MMR-d group, age = 66.5 ± 0.6; BMI = 30.6 ± 1.2; stage I = 72.6%; adjuvant treatment = 47.3%; in the POLE-mt group, age = 58.6 ± 2.7; BMI = 27.2 ± 0.9; stage I = 93.7%; adjuvant treatment = 53.6%; in the p53-wt group, age = 64.2 ± 1.9; BMI = 32.3 ± 1.4; stage I = 80.5%; adjuvant treatment = 45.3%; in the p53-abn group, age = 71.1 ± 0.5; BMI = 29.1 ± 0.5; stage I = 50.8%; adjuvant treatment = 64.4%. CONCLUSION: The ProMisE groups identify different phenotypes of patients. The POLE-mt group included the youngest women, with the lower BMI and the highest prevalence of stage I. The p53-wt group included patients with the highest BMI. The p53-abn group included the oldest women, with the highest prevalence of adjuvant treatment and the lowest prevalence of stage I. The MMR-d group showed intermediate values among the ProMisE groups for all clinical features.

Mast Cells Positive for c-Kit Receptor and Tryptase Correlate with Angiogenesis in Cancerous and Adjacent Normal Pancreatic Tissue.

BACKGROUND: Mast cells (MCs) contain proangiogenic factors, in particular tryptase, associated with increased angiogenesis in several tumours. With special reference to pancreatic cancer, few data have been published on the role of MCs in angiogenesis in both pancreatic ductal adenocarcinoma tissue (PDAT) and adjacent normal tissue (ANT). In this study, density of mast cells positive for c-Kit receptor (MCDP-c-KitR), density of mast cells positive for tryptase (MCDPT), area of mast cells positive for tryptase (MCAPT), and angiogenesis in terms of microvascular density (MVD) and endothelial area (EA) were evaluated in a total of 45 PDAT patients with stage T2-3N0-1M0. RESULTS: For each analysed tissue parameter, the mean ± standard deviation was evaluated in both PDAT and ANT and differences were evaluated by Student's t-test (p ranged from 0.001 to 0.005). Each analysed tissue parameter was then correlated to each other one by Pearson t-test analysis (p ranged from 0.01 to 0.03). No other correlation among MCDP-c-KitR, MCDPT, MCAPT, MVD, EA and the main clinical-pathological characteristics was found. CONCLUSIONS: Our results suggest that tissue parameters increased from ANT to PDAT and that mast cells are strongly associated with angiogenesis in PDAT. On this basis, the inhibition of MCs through tyrosine kinase inhibitors, such as masitinib, or inhibition of tryptase by gabexate mesylate may become potential novel antiangiogenetic approaches in pancreatic cancer therapy.

Genome-wide analysis of copy number alterations led to the characterisation of PDCD10 as oncogene in ovarian cancer.

Copy Number Alterations (CNAs) represent the most common genetic alterations identified in ovarian cancer cells, being responsible for the extensive genomic instability observed in this cancer. Here we report the identification of CNAs in a cohort of Italian patients affected by ovarian cancer performed by SNP-based array. Our analysis allowed the identification of 201 significantly altered chromosomal bands (70 copy number gains; 131 copy number losses). The 3300 genes subjected to CNA identified here were compared to those present in the TCGA dataset. The analysis allowed the identification of 11 genes with increased CN and mRNA expression (PDCD10, EBAG9, NUDCD1, ENY2, CSNK2A1, TBC1D20, ZCCHC3, STARD3, C19orf12, POP4, UQCRFS1). PDCD10 was selected for further studies because of the highest frequency of CNA. PDCD10 was found, by immunostaining of three different Tissue Micro Arrays, to be over-expressed in the majority of ovarian primary cancer samples and in metastatic lesions. Moreover, significant correlations were found in specific subsets of patients, between increased PDCD10 expression and grade (p < 0.005), nodal involvement (p < 0.05) or advanced FIGO stage (p < 0.01). Finally, manipulation of PDCD10 expression by shRNA in ovarian cancer cells (OVCAR-5 and OVCA429) demonstrated a positive role for PDCD10 in the control of cell growth and motility in vitro and tumorigenicity in vivo. In conclusion, this study allowed the identification of novel genes subjected to copy number alterations in ovarian cancer. In particular, the results reported here point to a prominent role of PDCD10 as a bona fide oncogene.

A rare case of ancient schwannoma of the tongue.

AIM: This is a case of Ancient schwannoma, an uncommon schwannoma variant, of clinical interest for the unusual site of the lesion, the diagnostic complexity and the surgical approach. CASE REPORT: We present a 40-year-old patient with intramural swelling of the lingual belly. Surgical removal was performed, and the diagnosis was confirmed by histopathological examination. DISCUSSION: We discuss the clinical findings and therapeutic strategies for treating and diagnosing ancient schwannoma. CONCLUSIONS: The specific diagnosis is difficult and frequently late. Growth is slow and only at a distance of time symptoms arise. These tumors must be treated surgically in the prevention of a possible recurrence. KEY WORDS: Ancient schwannoma, Intramural tongue mass, Antoni A and Antoni B bodies, Neurinoma, Neurilemoma.

Targeting Stem Cells with Hyperthermia: Translational Relevance in Cancer Patients.

BACKGROUND: Tumor recurrences or metastases remain a major hurdle in improving overall cancer survival. In anticancer therapy, some patients inevitably develop chemo-/radiotherapy resistance at some point. Cancer stem cells are the driving force of tumorigenesis, recurrences, and metastases, contributing also to the failure of some cancer treatments. SUMMARY: Emergent evidence suggests that stem cell diseases are at the base of human cancers, and tumor progression and chemo-/radiotherapy resistance may be dependent on just a small subpopulation of cancer stem cells. Hyperthermia can be a strong cancer treatment, especially when combined with radio- or chemotherapy. It is a relatively safe therapy, may kill or weaken tumor cells, and significantly increases the effectiveness of other treatments. However, these mechanisms remain largely unknown. A literature search was performed using PubMed including cited English publications. The search was last conducted in December 2019. Search phrases included "stem cells," "hyperthermia," "cancer," and "therapy." Abstracts, letters, editorials, and expert opinions were not considered for the drafting of the study. Key Message: Our goal was to focus on and to summarize different biological features of cancer stem cells and new therapeutic approaches using hyperthermia and its potential translation to human clinical trials.

Histopathological findings in a COVID-19 patient affected by ischemic gangrenous cholecystitis.

BACKGROUND: Since its first documentation, a novel coronavirus (SARS-CoV-2) infection has emerged worldwide, with the consequent declaration of a pandemic disease (COVID-19). Severe forms of acute respiratory failure can develop. In addition, SARS-CoV-2 may affect organs other than the lung, such as the liver, with frequent onset of late cholestasis. We here report the histological findings of a COVID-19 patient, affected by a tardive complication of acute ischemic and gangrenous cholecystitis with a perforated and relaxed gallbladder needing urgent surgery. CASE PRESENTATION: A 59-year-old Caucasian male, affected by acute respiratory failure secondary to SARS-CoV-2 infection was admitted to our intensive care unit (ICU). Due to the severity of the disease, invasive mechanical ventilation was instituted and SARS-CoV-2 treatment (azithromycin 250 mg once-daily and hydroxychloroquine 200 mg trice-daily) started. Enoxaparin 8000 IU twice-daily was also administered subcutaneously. At day 8 of ICU admission, the clinical condition improved and patient was extubated. At day 32, patient revealed abdominal pain without signs of peritonism at examination, with increased inflammatory and cholestasis indexes at blood tests. At a first abdominal CT scan, perihepatic effusion and a relaxed gallbladder with dense content were detected. The surgeon decided to wait and see the evolution of clinical conditions. The day after, conditions further worsened and a laparotomic cholecystectomy was performed. A relaxed and perforated ischemic gangrenous gallbladder, with a local tissue inflammation and perihepatic fluid, was intraoperatively met. The gallbladder and a sample of omentum, adherent to the gallbladder, were also sent for histological examination. Hematoxylin-eosin-stained slides display inflammatory infiltration and endoluminal obliteration of vessels, with wall breakthrough, hemorrhagic infarction, and nerve hypertrophy of the gallbladder. The mucosa of the gallbladder appears also atrophic. Omentum vessels also appear largely thrombosed. Immunohistochemistry demonstrates an endothelial overexpression of medium-size vessels (anti-CD31), while not in micro-vessels, with a remarkable activity of macrophages (anti-CD68) and T helper lymphocytes (anti-CD4) against gallbladder vessels. All these findings define a histological diagnosis of vasculitis of the gallbladder. CONCLUSIONS: Ischemic gangrenous cholecystitis can be a tardive complication of COVID-19, and it is characterized by a dysregulated host inflammatory response and thrombosis of medium-size vessels.

Long non-coding RNA NEAT1 targeting impairs the DNA repair machinery and triggers anti-tumor activity in multiple myeloma.

The biological role and therapeutic potential of long non-coding RNAs (lncRNAs) in multiple myeloma (MM) are still open questions. Herein, we investigated the functional significance of the oncogenic lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in MM. Our study demonstrates that NEAT1 expression level is higher in MM than in the majority of hematological malignancies. NEAT1 silencing by novel LNA-gapmeR antisense oligonucleotide inhibits MM cell proliferation and triggers apoptosis in vitro and in vivo murine MM model as well. By transcriptome analyses, we found that NEAT1 targeting downregulates genes involved in DNA repair processes including the Homologous Recombination pathway, which in turn results in massive DNA damage. These findings may explain the synergistic impact on apoptosis observed in MM cell lines co-treated with inhibitors of both NEAT1 and PARP. The translational significance of NEAT1 targeting is further underlined by its synergistic effects with the most common drugs administered for MM treatment, including bortezomib, carfilzomib, and melphalan. Overall, NEAT1 silencing is associated with a chemo-sensitizing effect of both conventional and novel therapies, and its targeting could therefore represent a promising strategy for novel anti-MM therapeutic options.

Trabectedin triggers direct and NK-mediated cytotoxicity in multiple myeloma.

BACKGROUND: Genomic instability is a feature of multiple myeloma (MM), and impairment in DNA damaging response (DDR) has an established role in disease pathobiology. Indeed, a deregulation of DNA repair pathways may contribute to genomic instability, to the establishment of drug resistance to genotoxic agents, and to the escape from immune surveillance. On these bases, we evaluated the role of different DDR pathways in MM and investigated, for the first time, the direct and immune-mediated anti-MM activity of the nucleotide excision repair (NER)-dependent agent trabectedin. METHODS: Gene-expression profiling (GEP) was carried out with HTA2.0 Affymetrix array. Evaluation of apoptosis, cell cycle, and changes in cytokine production and release have been performed in 2D and 3D Matrigel-spheroid models through flow cytometry on MM cell lines and patients-derived primary MM cells exposed to increasing nanomolar concentrations of trabectedin. DNA-damage response has been evaluated through Western blot, immunofluorescence, and DNA fragmentation assay. Trabectedin-induced activation of NK has been assessed by CD107a degranulation. miRNAs quantification has been done through RT-PCR. RESULTS: By comparing GEP meta-analysis of normal and MM plasma cells (PCs), we observed an enrichment in DNA NER genes in poor prognosis MM. Trabectedin triggered apoptosis in primary MM cells and MM cell lines in both 2D and 3D in vitro assays. Moreover, trabectedin induced DDR activation, cellular stress with ROS production, and cell cycle arrest. Additionally, a significant reduction of MCP1 cytokine and VEGF-A in U266-monocytes co-cultures was observed, confirming the impairment of MM-promoting milieu. Drug-induced cell stress in MM cells led to upregulation of NK activating receptors ligands (i.e., NKG2D), which translated into increased NK activation and degranulation. Mechanistically, this effect was linked to trabectedin-induced inhibition of NKG2D-ligands negative regulators IRF4 and IKZF1, as well as to miR-17 family downregulation in MM cells. CONCLUSIONS: Taken together, our findings indicate a pleiotropic activity of NER-targeting agent trabectedin, which appears a promising candidate for novel anti-MM therapeutic strategies.

miR-22 suppresses DNA ligase III addiction in multiple myeloma.

Multiple myeloma (MM) is a hematologic malignancy characterized by high genomic instability. Here we provide evidence that hyper-activation of DNA ligase III (LIG3) is crucial for genomic instability and survival of MM cells. LIG3 mRNA expression in MM patients correlates with shorter survival and even increases with more advanced stage of disease. Knockdown of LIG3 impairs MM cells viability in vitro and in vivo, suggesting that neoplastic plasmacells are dependent on LIG3-driven repair. To investigate the mechanisms involved in LIG3 expression, we investigated the post-transcriptional regulation. We identified miR-22-3p as effective negative regulator of LIG3 in MM. Enforced expression of miR-22 in MM cells downregulated LIG3 protein, which in turn increased DNA damage inhibiting in vitro and in vivo cell growth. Taken together, our findings demonstrate that myeloma cells are addicted to LIG3, which can be effectively inhibited by miR-22, promoting a novel axis of genome stability regulation.

Tumor-Associated Macrophages and Mast Cells Positive to Tryptase Are Correlated with Angiogenesis in Surgically-Treated Gastric Cancer Patients.

Mast cells and macrophages can play a role in tumor angiogenesis by stimulating microvascular density (MVD). The density of mast cells positive to tryptase (MCDPT), tumor-associated macrophages (TAMs), and MVD were evaluated in a series of 86 gastric cancer (GC) tissue samples from patients who had undergone potential curative surgery. MCDPT, TAMs, and MVD were assessed in tumor tissue (TT) and in adjacent normal tissue (ANT) by immunohistochemistry and image analysis. Each of the above parameters was correlated with the others and, in particular for TT, with important clinico-pathological features. In TT, a significant correlation between MCDPT, TAMs, and MVD was found by Pearson t-test analysis (p ranged from 0.01 to 0.02). No correlation to the clinico-pathological features was found. A significant difference in terms of mean MCDPT, TAMs, and MVD between TT and ANT was found (p ranged from 0.001 to 0.002). Obtained data suggest MCDPT, TAMs, and MVD increased from ANT to TT. Interestingly, MCDPT and TAMs are linked in the tumor microenvironment and they play a role in GC angiogenesis in a synergistic manner. The assessment of the combination of MCDPT and TAMs could represent a surrogate marker of angiogenesis and could be evaluated as a target of novel anti-angiogenic therapies in GC patients.

Drugging the lncRNA MALAT1 via LNA gapmeR ASO inhibits gene expression of proteasome subunits and triggers anti-multiple myeloma activity.

The biological role and therapeutic potential of long non-coding RNAs (lncRNAs) in multiple myeloma (MM) are still to be investigated. Here, we studied the functional significance and the druggability of the oncogenic lncRNA MALAT1 in MM. Targeting MALAT1 by novel LNA-gapmeR antisense oligonucleotide antagonized MM cell proliferation and triggered apoptosis both in vitro and in vivo in a murine xenograft model of human MM. Of note, antagonism of MALAT1 downmodulated the two major transcriptional activators of proteasome subunit genes, namely NRF1 and NRF2, and resulted in reduced trypsin, chymotrypsin and caspase-like proteasome activities and in accumulation of polyubiquitinated proteins. NRF1 and NRF2 decrease upon MALAT1 targeting was due to transcriptional activation of their negative regulator KEAP1, and resulted in reduced expression of anti-oxidant genes and increased ROS levels. In turn, NRF1 promoted MALAT1 expression thus establishing a positive feedback loop. Our findings demonstrate a crucial role of MALAT1 in the regulation of the proteasome machinery, and provide proof-of-concept that its targeting is a novel powerful option for the treatment of MM.

C-Kit receptor and tryptase expressing mast cells correlate with angiogenesis in breast cancer patients.

C-Kit protein is a transmembrane tyrosine kinase (TK) receptor (c-KitR-TK), which is predominantly expressed on mast cells (MCs) playing a role in tumor angiogenesis. It could be also expressed on epithelial breast cancer cells (EBCCs), but no data have been published regarding the correlation between mast cells positive to c-KitR (MCs-c-KitR), EBCCs positive to c-KitR (EBCCs-c-KitR), BC angiogenesis in terms of microvessel density (MVD) and the main clinic-pathological features. This study aims to evaluate the above parameters and their correlations in a series of selected 121 female early BC patients. It has been found a strong correlation between MVD and MCDPT, and MCs-c-KitR, MVD and MCs density positive to tryptase (MCDPT), and MCs-c-KitR and MCDPT by Pearson correlation. These data suggest an involvement of both MCDPT and MCs-c-KitR in BC tumor angiogenesis. Furthermore, BC tissue expressing c-KitR could be a putative predictive factor to c-KitR-TK inhibitors. In this way, selected patients with higher MCs-c-KitR could be candidate to receive c-KitR-TK inhibitors (e.g. masitinib, sunitinib) or tryptase inhibitors (e.g. nafamostat mesilate, gabexate mesilate).

The density of mast cells c-Kit+ and tryptase+ correlates with each other and with angiogenesis in pancreatic cancer patients.

Literature data suggest that inflammatory cells such as mast cells (MCs) are involved in angiogenesis. MCs can stimulate angiogenesis by releasing of well identified pro-angiogenic cytokines stored in their cytoplasm. In particular, MCs can release tryptase, a potent in vivo and in vitro pro-angiogenic factor. Nevertheless, few data are available concerning the role of MCs positive to tryptase in primary pancreatic cancer angiogenesis. This study analyzed the correlation between mast cells positive to c-Kit receptor (c-Kit+ MCs), the density of MCs expressing tryptase (MCD-T) and microvascular density (MVD) in primary tumor tissue from patients affected by pancreatic ductal adenocarcinoma (PDAC). A series of 35 PDAC patients with stage T2-3N0-1M0 (by AJCC for Pancreas Cancer Staging 7th Edition) were selected and then undergone to surgery. Tumor tissue samples were evaluated by mean of immunohistochemistry and image analysis methods in terms of number of c-Kit+ MCs, MCD-T and MVD. The above parameters were related each other and with the most important main clinico-pathological features. A significant correlation between c-Kit+ MCs, MCD-T and MVD groups each other was found by Pearson t-test analysis (r ranged from 0.75 to 0.87; p-value ranged from 0.01 to 0.04). No other significant correlation was found. Our in vivo preliminary data, suggest that tumor microenvironmental MCs evaluated in terms of c-Kit+ MCs and MCD-T may play a role in PDAC angiogenesis and they could be further evaluated as a novel tumor biomarker and as a target of anti-angiogenic therapy.