Advances in digital pathology and artificial intelligence (AI) are significantly transforming the approach to analyzing the tumor microenvironment (TME) in gastrointestinal cancers (GICs). The TME consists of tumor cells, stromal components, and immune cells. It plays a key role in disease progression, treatment response, and patient prognosis. This review discusses the most important TME biomarkers, such as tumor budding (TB), tumor-infiltrating lymphocytes (TILs), and tertiary lymphoid structures (TLSs), with emphasis on their prognostic and predictive significance. Traditional histopathological assessment of these parameters is limited by subjectivity, intraobserver variability, and time-consuming nature. In this context, AI-based tools enable automated, quantitative, and more reproducible analysis of entire histological sections. Deep learning models allow the accurate detection and classification of structures and also analysis of their spatial organization. They provide new biological insights unavailable in routine diagnostics. The integration of imaging data with molecular and clinical information leads to the development of personalized medicine. Despite numerous advantages, the implementation of AI in clinical practice continues to face challenges related to standardization, data availability, and model interpretability.

Antineutrophil cytoplasmic antibodies (ANCA)-negative pauci-immune necrotizing glomerulonephritis (PING) is a rare entity, representing a distinct subset of small-vessel vasculitis. The absence of ANCA does not exclude the diagnosis, and clinical suspicion should remain high in the presence of compatible systemic and renal findings. We present the case of a 22-year-old woman with recurrent, non-specific cutaneous manifestations since early childhood, who was hospitalized for an exacerbation of skin lesions. Laboratory results revealed nephrotic-range proteinuria of 17 g/d [N < 150 mg/d] and a reduced estimated glomerular filtration rate (eGFR) of 47 mL/min/1.73 m² [N > 90 mL/min/1.73 m²]. Renal biopsy results demonstrated cellular crescents, focal segmental tubular necrosis, intense mononuclear inflammatory infiltrates, and segmental proliferation of Bowman’s capsule epithelial cells. Direct immunofluorescence yielded negative results for IgG, IgA, IgM, C3, or C1q deposits. Electron microscopy confirmed segmental podocyte foot process effacement and microvillous transformation. Serologic testing was comprehensively negative, specifically confirming the absence of PR3-ANCA, MPO-ANCA, anti-glomerular basement membrane (GBM) antibodies, and serum cryoglobulins. Based on the clinical, histologic, and immunopathologic findings, a definitive diagnosis of isolated ANCA-negative PING was established, although atypical features prompted the consideration of secondary podocytopathy. Methylprednisolone therapy was initiated, but progressive renal deterioration following a substantial loss to follow-up period necessitated renal replacement therapy. This report underscores the diagnostic challenge of ANCA-negative PING, given its absent serologic markers and overlapping features with other glomerular diseases, highlighting the crucial role of renal biopsy in reaching a timely diagnosis.

Background: Genetic testing is an increasingly important component in the diagnostic evaluation of kidney diseases. Pathogenic variants in the HNF1B gene cause a disorder classically known as renal cysts and diabetes (RCAD) syndrome, typically characterised by bilateral renal cysts, diabetes mellitus, and a broad spectrum of other extrarenal abnormalities. However, non-cystic presentations often lead to diagnostic delays. Case Report: We report the case of a 28-year-old woman evaluated for chronic kidney disease of unknown aetiology who presented with atypical radiological findings. Imaging revealed bilateral renal hypoplasia completely devoid of cystic transformation. The patient exhibited no proteinuria, electrolyte or acid–base disturbances, diabetes mellitus, or pancreatic abnormalities. Next-generation sequencing identified pathogenic HNF1B missense variant (p.Met160Val), confirming the diagnosis of genetic kidney disease. The patient’s clinical course remained stable throughout the follow-up period. Conclusions: This case illustrates the marked phenotypic heterogeneity of HNF1B-associated disease and supports incorporating genetic testing in patients with unexplained structural kidney abnormalities, even in the absence of classical cystic renal disease or typical extrarenal manifestations, to ensure accurate diagnosis and treatment, and to facilitate appropriate family counselling.

Male infertility represents a major clinical challenge. Despite standard genetic testing (karyotyping, Y-chromosome azoospermia factor (AZF) microdeletion testing, and CFTR variant analysis), the molecular cause remains unidentified in a substantial proportion of patients. These patients are consequently diagnosed with idiopathic male infertility. This review provides a comprehensive overview of the current evidence regarding the application of whole-exome sequencing (WES) in the molecular diagnosis and clinical management of idiopathic male infertility. WES can identify pathogenic variants associated with quantitative spermatogenic defects, qualitative abnormalities of sperm motility and morphology, and pre-testicular causes related to hypogonadotropic hypogonadism. When defining the cohort strictly as patients with true idiopathic non-obstructive azoospermia (NOA) who remain undiagnosed after standard testing, the pooled diagnostic yield of WES is approximately 10–15%. Estimates vary due to differences in cohort selection, variant interpretation, and the range of genes analysed. Establishing a precise molecular diagnosis improves genetic counselling, helps predict the likelihood of successful sperm retrieval via testicular sperm extraction (TESE) or microdissection TESE (micro-TESE), and informs treatment planning for assisted reproductive technologies. However, routine clinical implementation remains limited by the high frequency of variants of uncertain significance, the absence of standardised diagnostic pipelines, unequal access to testing, and ethical concerns. Emerging “all-in-one” diagnostic strategies, multi-omics integration, and whole-genome or long-read sequencing hold promise for improving genomic diagnostics. However, broader adoption will ultimately require ongoing standardisation and functional validation of identified variants.

Oncolytic viruses (OVs) are increasingly viewed not only as tumor-lysing agents but also as immunotherapeutic platforms capable of functioning as in situ cancer vaccines. By selectively infecting malignant cells, inducing immunogenic cell death, releasing tumor-associated antigens and danger signals, and activating innate and adaptive immunity, OVs can remodel immune-desert or immune-excluded tumors. This narrative review integrates mechanistic and clinical evidence on tumor-selective viral replication, antigen presentation, dendritic-cell activation, type I interferon signaling, and the recruitment of cytotoxic T lymphocytes and natural killer cells. Particular attention is given to the effects of OVs on regulatory T cells, myeloid-derived suppressor cells, tumor-associated macrophages, cancer-associated fibroblasts, and extracellular matrix barriers. We further examine the biological rationale and clinical outcomes of combining OVs with immune checkpoint inhibitors, emphasizing the discrepancy between promising preclinical findings and inconsistent clinical efficacy. A stepwise translational framework is proposed to distinguish failures in delivery and replication from inadequate immune conversion, checkpoint-restrained immunity, and non-checkpoint-dominant resistance. Finally, we discuss antiviral immunity, safety, viral engineering, and tissue-based, circulating, and genomic biomarkers that may support patient selection and guide next-generation OV-based combination strategies.