The BK polyomavirus (BKPyV), a representative of the family Polyomaviridae, is widespread in the human population. While the virus does not cause significant clinical symptoms in immunocompetent individuals, it is activated in cases of immune deficiency, both pharmacological and pathological. Infection with the BKPyV is of particular importance in recipients of kidney transplants or HSC transplantation, in which it can lead to the loss of the transplanted kidney or to haemorrhagic cystitis, respectively. Four main genotypes of the virus are distinguished on the basis of molecular differentiation. The most common genotype worldwide is genotype I, with a frequency of about 80%, followed by genotype IV (about 15%), while genotypes II and III are isolated only sporadically. The distribution of the molecular variants of the virus is associated with the region of origin. BKPyV subtype Ia is most common in Africa, Ib-1 in Southeast Asia, and Ib-2 in Europe, while Ic is the most common variant in Northeast Asia. The development of molecular methods has enabled significant improvement not only in BKPyV diagnostics, but in monitoring the effectiveness of treatment as well. Amplification of viral DNA from urine by PCR (Polymerase Chain Reaction) and qPCR Quantitative Polymerase Chain Reaction) is a non-invasive method that can be used to confirm the presence of the genetic material of the virus and to determine the viral load. Sequencing techniques together with bioinformatics tools and databases can be used to determine variants of the virus, analyse their circulation in populations, identify relationships between them, and investigate the directions of evolution of the virus.

The BK polyomavirus (BKPyV) is a widespread pathogen in humans. Polymorphism of the region encoding the VP1 protein of BKPyV provides the basis for classifying the virus into types and subtypes, whose frequency varies depending on geographic location. The aim of our study was to determine the frequency of BKPyV in the Polish population and to assess its variation by analysing polymorphism in the typing region. The study was conducted on 168 healthy, Polish volunteers, whose blood (plasma) and urine were sampled. The virus was detected using PCR, products, sequenced and subjected to bioinformatic analysis. In addition, viral load was assessed by qPCR. The presence of the genetic material of the BK virus was noted in 61/168 urine samples but in none of the plasma sample. Sequencing and phylogenetic analysis confirmed that the BKPyV isolates were of types I and IV, dominant in Europe (63.93% and 36.07%, respectively). All isolates from genotype I belonged to subtype Ib-2, showing polymorphism at position 1809 with a frequency of 61.54% (G1809A) and 38.46% (G1809C). To the best of our knowledge, this is the first study of this magnitude on the genetic variation of BKPyV among healthy volunteers in Poland.

CT-guided lung biopsy is a widely used procedure for tissue identification. The complications are divided into minor and major with the latter being described as low rate. Hemothorax is reported at a rate of 0.092% and predominantly results from the injury of intercostals or internal mammary arteries. We present the case of 81-year old woman with a right upper lobe mass referred for a CT-guided biopsy. Four hours after the procedure, rapid deterioration of patient's status was observed. A massive hemothorax was reported due to the transection of an intratumoral pulmonary branch. The following management involved successful emergent embolization of the injured branch of the pulmonary artery using a combination of coils and gel foam. One of the theories possibly explaining this extremely rare complication involves the possibility of underlying pulmonary hypertension.

Background: Vascular malformations (VMs) are congenital anomalies of the vascular system—capillary, venous, lymphatic, arteriovenous, or combined—frequently associated with notable morbidity and reduced quality of life. Electrochemotherapy (ECT), a locoregional treatment that combines chemotherapeutic agents (most commonly bleomycin) with electroporation, has emerged as a promising alternative in managing therapy-resistant or anatomically challenging lesions. Methods: A systematic review of the literature was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Embase, and the Cochrane Library were searched from inception to January 2025 for studies reporting on the efficacy and/or safety of ECT for vascular malformations. Data extraction encompassed study design, patient demographics, VM type, ECT protocols, outcomes, follow-up duration, and adverse events. Studies that lacked relevant outcome data or focused solely on other therapeutic approaches were excluded. Results: Twelve primary studies met the inclusion criteria and were analyzed. These covered diverse VMs, including venous, slow-flow, high-flow malformations, aggressive hemangiomas, and composite lesions in adult and pediatric populations. ECT protocols usually combined bleomycin (or occasionally other agents such as pingyangmycin or polidocanol foam) with various electroporation parameters. Across studies, ECT resulted in meaningful lesion-size reduction (50–97% in most cohorts), symptom relief (e.g., reduced pain and bleeding), and favorable cosmetic outcomes. While side effects (local edema, hyperpigmentation, procedure-related discomfort) were occasionally reported, they were typically mild and transient. Conclusions: ECT represents a valuable minimally invasive option in the therapeutic armamentarium for vascular malformations. Despite consistent demonstrations of efficacy and acceptable toxicity profiles, future high-quality, multicenter studies are warranted to confirm outcomes, refine treatment guidelines, and potentially expand its use as a standard of care.

Fibrolipomatous hamartomas of the median nerve are rare, benign tumors characterized by the overgrowth of fibro-fatty tissue within the nerve sheath, often leading to nerve compression. This report presents 2 cases: a 33-year-old man with a gradually enlarging wrist mass and a 48-year-old woman, initially diagnosed with De Quervain's tenosynovitis for radial pain, who was found to have an incidental fibrolipomatous hamartoma on MRI. In both cases, MRI played a pivotal role in diagnosis, revealing characteristic features that enabled a definitive, noninvasive diagnosis. Early recognition of these MRI findings is essential for guiding management and preventing unnecessary surgical interventions.

Kidney transplantation from a donor with latent BKPyV might be the cause of serious complications, such as BK virus-associated nephropathy. The aim of the study was to determine the prevalence of BKPyV infection in donors after brain death (DBDs), to analyse the molecular variation of BKPyV and to compare clinical and inflammation parameters of DBDs infected with various genotypes of BKPyV. BKPyV was investigated in blood and urine samples of 103 DBDs using PCR followed by sequencing and bioinformatic analysis, and the viral load was assessed by qPCR. Clinical parameters, including cellular markers of inflammation were assessed. The results confirm high prevalence of BKPyV (48%),and genotype IV (49%) over genotype I (43%) and the co-infection with genotypes I and IV in 8.2%. Viral load ranged from 10² to 10⁷ copies/mL, with an average of 1.92 × 10⁶ copies/mL. No specific markers for BKPyV infection were detected among the parameters tested. Infection with genotype I may be associated with the adverse impact on thekidney function, while infection with genotype IV was associated with the anemia Not only the viral load but also the genotype of BKPyV may have an impact on the course of infection.