IMMUNOREACT 9 metachronous rectal cancers have high HLA-ABC expression on healthy epithelium but a lower infiltration of CD3+ T cells than primary lesions.

Lynch syndrome is rarely associated with rectal cancer (RC) and thus, metachronous RC has been scarcely investigated. This study aimed to analyze the mucosal immune microenvironment in sporadic and metachronous RC. We analyzed the mucosal immune microenvironment in the 25 metachronous RCs present in the IMMUNOREACT 1 and 2 multicentre observational studies (624 patients).

IMMUNOREACT 8: Immune markers of local tumor spread in patients undergoing transanal excision for clinically N0 rectal cancer.

Background: Transanal excision of rectal cancer can be considered the definitive surgical treatment if the depth spread is T1 or lower, and the lesion is completely included within the resection margin. This study aims to analyze the immune microenvironment in healthy rectal mucosa as a possible predictor of tumor infiltration depth, lateral tumor spread, and recurrence of rectal cancer after transanal local excision.

Methods: This study is a subanalysis of data from the IMMUNOREACT 1 and 2 trials (NCT04915326 and NCT04917263, respectively) including all the patients who underwent transanal excision of rectal cancer.

Microscopic sex cord-stromal proliferations in extraovarian heterotopic sites: Report of a rare case and review of the literature.

Microscopic heterotopic extraovarian sex cord-stromal proliferations were first reported in the literature in 2015 by McCluggege. Afterwards, few similar cases have been described. Herein, we report the fourteenth case of microscopic heterotopic sex cord-stromal proliferation and the third case sited in the pelvic peritoneum.

IMMUNOREACT 6: weak immune surveillance characterizes early-onset rectal cancer.

Background: Colon cancer in young patients is often associated with hereditary syndromes; however, in early-onset rectal cancer, mutations of these genes are rarely observed. The aim of this study was to analyse the features of the local immune microenvironment and the mutational pattern in early-onset rectal cancer.

Methods: Commonly mutated genes were analysed within a rectal cancer series from the University Hospital of Padova.

Role of Immune Microenvironment in Pancreatic Ductal Adenocarcinoma: Could It Be Considered a Predictor of Prognosis?

Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by a highly immunosuppressive tumor microenvironment (TME). The aim of this study is to determine the potential significant TME immune markers of long-term survival.

Methods: We retrospectively included patients with a diagnosis of resectable PDAC having undergone upfront surgery.

The Day-To-Day Practice of MMR and MSI Assessment in Colorectal Adenocarcinoma: What We Know and What We Still Need to Explore.

Background: The DNA mismatch repair (MMR) system is a highly preserved protein complex recognizing short insertions, short deletions, and single base mismatches during DNA replication and recombination. MMR protein status is identified using immunohistochemistry. Deficit in one or more MMR proteins, configuring deficient MMR status (dMMR), leads to frameshift mutations particularly clustered in microsatellite repeats.

Higher accuracy of surgical over core needle biopsy for the diagnosis of lymphoproliferative disorders.

Introduction: The diagnosis of lymphoproliferative disorders (LPDs) is based on histological evaluation of representative tissue samples. Despite surgical excision biopsies (SEBs) are reference procedures for such diagnoses, lymph node core needle biopsies (LNCBs) are increasingly performed. The diagnostic yield of LNCB is, however, debated and few studies have compared the reproducibility of LNCB and SEB findings.

Morphological and molecular characterization of colorectal sessile serrated lesions with dysplasia.

In sessile serrated lesions (SSLs) with adenomatous dysplasia, the dysplastic component and the serrated component without dysplasia should be considered as part of the same lesion, classified as SSL with dysplasia. However, some of these lesions may actually represent collisions between a serrated polyp and a conventional adenoma. Further supporting the "collision theory", conventional adenomatous dysplasia may be found in association with hyperplastic polyps (HPs).

Beware of Histiocytes: Whipple Adenopathy and its Mimics.

Histiocytic proliferations are heterogeneous lesions with distinct pathogenic and clinical-pathological features. While many of these conditions are nonspecific immune responses to variable causes, a minority of them is associated with specific etiological factors and unique clinical-pathological pictures. By presenting a rare case of Whipple adenopathy, we address the peculiar histological features of this condition and the differential diagnosis of nodal histiocytosis in general.

Incidental lymphomas in surgical pathology: diagnostic clues and clinical-pathological correlations.

Incidental lymphomas (ILs) are rare and challenging lesions with poorly characterized clinical-epidemiological and histological features. The present study addressed the open issues concerning these tumors, by assessing the clinical-pathological features of 28 consecutive ILs, diagnosed over a 10-year period at a tertiary center for surgical pathology. ILs were more frequently documented in elderly males (mean age at surgery 70.

MicroRNAs as Predictive Biomarkers of Resistance to Targeted Therapies in Gastrointestinal Tumors.

The advent of precision therapies against specific gene alterations characterizing different neoplasms is revolutionizing the oncology field, opening novel treatment scenarios. However, the onset of resistance mechanisms put in place by the tumor is increasingly emerging, making the use of these drugs ineffective over time. Therefore, the search for indicators that can monitor the development of resistance mechanisms and above all ways to overcome it, is increasingly important.

Circulating microRNA expression profiling revealed miR-92a-3p as a novel biomarker of Barrett's carcinogenesis.

The main intent of secondary prevention strategies for Barrett's esophagus (BE) patients relies in the prompt identification of patients with dysplasia (or intra-epithelial neoplasia; IEN) and early-stage adenocarcinoma (Barrett's adenocarcinoma; BAc). Despite the adequate characterization of the molecular landscape characterizing Barrett's carcinogenesis, no tissue and/or circulating biomarker has been approved for clinical use. A series of 25 serum samples (12 BE, 5 HG-IEN and 8 BAc) were analyzed for comprehensive miRNA profiling and ten miRNAs were found to be significantly dysregulated.

The heterogeneous clinical and pathological landscapes of metastatic -mutated colorectal cancer.

Colorectal cancer (CRC) is a complex and molecularly heterogeneous disease representing one of the most frequent causes of cancer-related death worldwide. About 8-15% of CRCs harbor a mutation in gene, a proto-oncogene involved in cell proliferation, differentiation and survival through the MAPK signaling cascade. The acquisition of mutation is an early event in the "serrated" CRC carcinogenetic pathway and is associated with specific and aggressive clinico-pathological and molecular features.

Mutational and Immunophenotypic Profiling of a Series of 8 Tubo-ovarian Carcinosarcomas Revealed a Monoclonal Origin of the Disease.

Carcinosarcomas are rare, highly aggressive neoplasms composed of a combination of carcinomatous and sarcomatous elements. These tumors represent a paradigmatic field for the study of intratumor heterogeneity. A series of 8 tubo-ovarian carcinosarcomas was characterized for the following: (i) immunohistochemical expression of MNF116, epithelial membrane antigen, vimentin, S100, chromogranin, synaptophysin, desmin, myogenin (MYF4), and p53; (ii) mutational profiling of KRAS, BRAF, PIK3CA, NRAS, TP53, and DICER1 genes.