Background. Although amplification of the gene encoding human epidermal growth factor receptor 2 (HER2) is used as an indicator for response to trastuzumab, the reported response rate is low, and few patients with gastric cancer (GC) benefit from this individualized therapy. The aim of this study was to examine the expression of c-erbB-2 oncoprotein (HER2), in GC samples, using two commercial immunohistochemical (IHC) antibodies, and to validate the results by checking HER2 gene amplification by fluorescence in situ hybridization (FISH). Methods. We assessed the IHC expression of HER2 using the polyclonal antibody from Dako and CB11 clone from Leica, in 93 consecutive cases of GC samples. In all of the cases, FISH analysis was also performed using the BOND-MAX platform. Results. No significant difference was observed between the two HER2 antibodies. Of the 93 cases, 22.58 demonstrated at least focal and 1+ HER2 positivity. Seven cases (7.53) exhibited 3+ expression, and another 7 carcinomas (7.53) were equivocal (2+). HER2 amplification was seen in 11 cases (11.83), 10 of which were differentiated adenocarcinomas. In 5 of the cases, 25 sections were examined, which proved the extremely high intratumorally/intraglandular heterogeneity. FISH heterogeneity was higher in cases with only 2+ positivity on IHC assessment, compared with those showing at least one small focus of 3+ overexpression. HER2 amplification proved to be an independent negative prognostic factor. Conclusions. Due to the highly heterogeneous aspect of GC, at least 3-4 slides should be assessed by IHC, before considering a tumor to be HER2-negative. In cases with small 3+ foci representing less than 5 of tumor and in equivocal (2+) cases, FISH analysis remains the gold standard method.

In gastric cancer (GC), intestinal metaplasia (IM) is a common precursor lesion, but its relationship to the MUC2/MUC5AC/CDX2 axis is not completely understood. Although V-set and immunoglobulin domain containing 1 (VSIG1) is supposed to be a specific marker for gastric mucosa and GC, respectively, no data about its relationship with IM or mucin phenotype have been published. The aim of our study was to explore the possible linkage between IM and these four molecules. The clinicopathological features of 60 randomly selected GCs were examined in association with VSIG1, MUC2, MUC5AC and CDX2. Two online database platforms were also used to establish the transcription factors (TFs) network involved in MUC2/MUC5AC/CDX2 cascade. IM was more frequently encountered in females (11/16 cases) and in patients below 60 years old (10/16 cases). Poorly differentiated (G3) carcinomas tended to show a loss of CDX2 (27/33 cases) but not of MUC2 and MUC5AC. MUC5AC and CDX2 were lost in parallel with the depth of invasion of the pT4 stage (28/35 and 29/35 cases), while an advanced Dukes-MAC-like stage was only correlated with CDX2 and VSIG1 loss (20/37 and 30/37 cases). VSIG1 was directly correlated with MUC5AC (p = 0.04) as an indicator of gastric phenotype. MUC2-negative cases showed a propensity towards lymphatic invasion (37/40 cases) and distant metastases, while CDX2-negative cases tended to associate with hematogenous dissemination (30/40 cases). Regarding the molecular network, only 3 of the 19 TFs involved in this carcinogenic cascade (SP1, RELA, NFKB1) interacted with all targeted genes. In GC, VSIG1 can be considered an indicator of gastric phenotype carcinomas, where carcinogenesis is mainly driven by MUC5AC. Although infrequently encountered in GC, CDX2 positivity might indicate a locally advanced stage and risk for vascular invasion, especially in tumors developed against the background of IM. The loss of VSIG1 indicates a risk for lymph node metastases.

Heart transplantation is undergoing a continuous development, with rates of success increasing substantially due to advances in immunosuppressive therapy and surgical techniques. The most worrying complication occurring after cardiac transplantation is graft rejection, a phenomenon that is much affected by matrix metalloproteinases (MMPs), with the role of these proteases in the cardiac remodeling process being well established in the literature. A detailed investigation of the association between MMPs and cardiac rejection is necessary for the future development of more targeted therapies in transplanted patients, and to discover prognostic serum and immunohistochemical markers that will lead to more organized therapeutic management in these patients. The aim of this review is therefore to highlight the main MMPs relevant to cardiovascular pathology, with particular emphasis on those involved in complications related to heart transplantation, including cardiac graft rejection.

Phantom limb pain (PLP) is a frequent and often persistent consequence of limb amputation, characterized by pain perceived in the absent limb. Despite decades of research, its biological basis remains incompletely understood, and available treatments often provide inconsistent relief. This reflects the complex and heterogeneous nature of phantom limb pain, which cannot be explained by a single anatomical site or pathological process. Current evidence suggests that phantom limb pain emerges from the interaction of changes occurring at multiple levels of the nervous system. Peripheral nerve injury associated with amputation induces molecular and cellular alterations that may influence early nociceptive signaling. These changes can interact with adaptive and maladaptive responses within the spinal cord, including altered synaptic transmission and neuron–glia interactions, which may facilitate sustained amplification of pain-related signals. At supraspinal levels, long-term adaptations within distributed neural networks involved in sensory, motor, and affective processing may contribute to the persistence of pain perceptions in the absence of ongoing peripheral input. Immune-related signaling and long-term regulation of gene expression further modulate these processes and may contribute to inter-individual variability. In this narrative review, we synthesize current experimental and clinical evidence addressing the molecular and cellular processes associated with phantom limb pain following lower limb amputation. Findings are integrated across peripheral, spinal, and supraspinal levels, with consideration of immune-related and regulatory influences. By highlighting areas of convergence, uncertainty, and existing knowledge gaps, this review aims to provide a coherent biological framework that may support future experimental and translational research in this challenging field.

Chylous ascites represents a relatively uncommon condition. In this paper, we present a case of chyloperitoneum associated with pancreatic ductal adenocarcinoma (PDAC) and a review of literature regarding chylous ascites. A 76-year-old male patient was admitted in emergency department with acute abdomen. A pancreatic cancer was suspected. Subtotal spleno-pancreatectomy, for a nodular mass infiltrating the mild and distal portion of the pancreas, was necessary. During surgical intervention in the peritoneal cavity, a moderate quantity of whitish and thick consistency fluid with milk-like appearance was observed to be accumulated. After examination of the fluid, chyloperitoneum was diagnosed. The histologic examination showed a PDAC, with multiple emboli in lymph vessels, with tumor cells with plasmacytoid morphology, diagnosed as lymphangiosis carcinomatosa. The patient died at 3 weeks after surgical intervention. In patients with pancreatic cancer and chylous ascites, suspicion of tumor-related blockage of the lymphatic flow should be suspected. Prognosis of PDAC should be evaluated not only based on the number of lymph node metastases, but also considering the number of lymph vessels with tumor emboli and the architecture of tumor cells. This is the first reported case of a PDAC with plasmacytoid morphology of lymphangiosis carcinomatosa. C.B.S. drafted the paper and performed study design. T.B. performed the surgical intervention and follow-up of clinical data. I.J. participated at the interpretation of histological slides and diagnosis interpretation. V.T. contributed to the literature review. S.G. participated at the histological diagnosis and paper design and conferred the final agreement for publication. ^* Authors contributed equally to the paper. Received: 06 July 2020 Accepted: 17 February 2021 Article published online: 19 July 2021 © 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/) Thieme Medical Publishers, Inc. 333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

The signet-ring cell variant of squamous cell carcinoma (SCC) is an extremely rare histological subtype, with only 24 cases (including the present case) reported in the Medline database: 15 affecting the external surface of the body, 3 in the lung, 2 affecting the uterine cervix, 1 involving the gingiva, another one affecting the esophagus and the present case that is the first reported at the gastro-esophageal junction (GEJ). In one case, the location of the lesion was not mentioned. A 59-year-old male patient underwent segmental eso-gastrectomy for carcinoma of the GEJ. The microscopic examination showed a pT3N1-staged SCC composed of solid nests admixed in over 30% of the tumor, with cells having eccentrically located nuclei and clear vacuolated cytoplasm. The signet-ring cells did not show mucinous secretion and were positive for keratin 5/6 and vimentin, with nuclear expression of β-catenin and Sox2 and focal membrane positivity for E-cadherin. Based on these features, the case was considered a signet-ring SCC with epithelial–mesenchymal transition. Thirty-one months after surgery, the patient was disease-free, with no local recurrence and no known distant metastases. In SCC, a signet-ring cell component might be an indicator of the dedifferentiation of tumor cells towards a mesenchymal molecular subtype.