(1) Background: endobronchial ultrasound-guided mediastinal transbronchial cryo-node biopsy, previously assisted by fine-needle aspiration, is a novel technique of particular interest in the field of lung cancer diagnosis and is of great utility for extrathoracic tumor metastases, lymphomas, and granulomatous diseases. An integrated histological and molecular diagnosis of small samples implies additional difficulty for the pathologist. Additionally, emerging tumor biomarkers create the need to search for new approaches to better manage the tissue sample; (2) Methods: An analytical observational study of 32 mediastinal node cryobiopsies is carried out in 27 patients (n = 27). Statistical analysis using the t-student and Wilcoxon signed-rank tests for paired data is performed with SPSS 26 and R Statistical software. The significance level is established at p < 0.05; (3) Results: cryobiopsies were valid for diagnosis in 25 of 27 patients, with a maximum average size of 3.5 ± 0.7 mm. A total of 18 samples (66.67%) were positive for malignancy and 9 (33.33%) were benign. The tumor percentage measured in all neoplastic samples was greater than 30%. The average DNA and RNA extracted in nine non-small cell lung cancer cases was 97.2 ± 22.4 ng/µL and 26.6 ± 4.9 ng/µL, respectively; (4) Conclusions: the sample size obtained from an endobronchial ultrasound-guided mediastinal transbronchial cryo-node biopsy facilitates the morphological and histo-architectural assessment of inflammatory and neoplastic pathology. It optimizes molecular tests in the latter due to more tumor cells, DNA, and RNA.

Different types of scaffolds are used to reconstruct muscle volume loss injuries. In this experimental study, we correlated ultrasound observations with histological findings in a muscle volume loss injury reconstructed with autologous adipose tissue. The outcome is compared with decellularized and porous matrix implants. Autologous adipose tissue, decellularized matrix, and a porous collagen matrix were implanted in volumetric muscle loss (VML) injuries generated on the anterior tibial muscles of Wistar rats. Sixty days after implantation, ultrasound findings were compared with histological and histomorphometric analysis. The muscles with an autologous adipose tissue implant exhibited an ultrasound pattern that was quite similar to that of the regenerative control muscles. From a histological point of view, the defects had been occupied by newly formed muscle tissue with certain structural abnormalities that would explain the differences between the ultrasound patterns of the normal control muscles and the regenerated ones. While the decellularized muscle matrix implant resulted in fibrosis and an inflammatory response, the porous collagen matrix implant was replaced by regenerative muscle fibers with neurogenic atrophy and fibrosis. In both cases, the ultrasound images reflected echogenic, echotextural, and vascular changes compatible with the histological findings of failed muscle regeneration. The ultrasound analysis confirmed the histological findings observed in the VML injuries reconstructed by autologous adipose tissue implantation. Ultrasound can be a useful tool for evaluating the structure of muscles reconstructed through tissue engineering.

Background: Angiomyolipoma is a benign mesenchymal neoplasm of a wide histological heterogeneity belonging to the PEComa “family.” The liver, after the kidney, is their second most frequent location. However, inflammatory hepatic AMLs constitute a rare entity, with only fourteen documented cases until 2020. These neoplasms can overlap morphological features of IgG4-related diseases, being of great diagnostic relevance to demonstrating myomelanocytic-lineage differentiation of the neoplastic cells. Case presentation: we present a new case of an inflammatory hepatic AML resembling an IgG4-related disease in a 35-year-old woman with a subcapsular 5 cm mass confined to segment VII of the right hepatic lobe. Although having reduced its size along the tumor’s natural evolution, complete tumor resection was decided due to its hypermetabolic behavior (max. SUV = 12,6) assessed by PET-CT scan. Finally, the patient underwent a right hepatectomy due to spontaneous rupture and bleeding of the lesion during the intervention. All the diagnostic and therapeutic procedures occurred in the last months of the COVID-19 pandemic. Conclusions: This review aims to describe inflammatory hepatic AML histological and immunohistochemical features. We further sought to establish a clinicopathological contextualization of this tumoral subtype.

Background: In volumetric muscle loss (VML) injuries, spontaneous muscle regeneration capacity is limited. The implantation of autologous adipose tissue in the affected area is an option to treat these lesions; however, the effectiveness of this therapy alone is insufficient for a complete recovery of the damaged muscle. This study examined the influence of treadmill exercise on the rehabilitation of VML injuries reconstructed with autologous adipose tissue, as a strategy to counteract the limitations of spontaneous regeneration observed in these injuries. Methods: Forty adult male Wistar rats were divided into eight groups of five individuals each: normal control (NC), regenerative control (RC), VML control (VML), VML injury reconstructed with fresh autologous adipose tissue (FAT), exercise-rehabilitated control (RNC), exercise-rehabilitated regenerative control (RRC), exercise-rehabilitated VML injury (RVML), and exercise-rehabilitated VML injury reconstructed with fresh autologous adipose tissue (RFAT). Histological and histochemical staining techniques were used for the analysis of structural features and histomorphometric parameters of the tibialis anterior muscle. Grip strength tests were conducted to assess muscle force. Results: Exercise rehabilitation decreased the proportion of disoriented fibers in RFAT vs. FAT group. The percentage of fibrosis was significantly higher in FAT and RFAT groups versus NC and RNC groups but did not vary significantly between FAT and RFAT groups. Overall, muscle grip strength and fiber size increased significantly in the exercise-rehabilitated groups compared to control groups. Conclusions: To conclude, rehabilitation with physical exercise tended to normalize the process of muscle repair in a model of VML injury reconstructed with fresh autologous adipose tissue, but it did not reduce the intense fibrosis associated with these injuries.

The application of implantable biomaterials in reconstructive grafting is a common practice in surgical fields such as orthopedics, maxillary and plastic surgery. This study explores the regenerative response of skeletal muscle to a porous bovine collagen-based matrix (Osteovit®) in a volumetric muscle loss injury model. Forty male Wistar rats were divided into four groups. Normal control underwent no procedure and regenerative control had mepivacaine injected in the tibialis anterior muscle to provoke a standard regenerative response. In the other two groups, a volumetric defect was created in the tibialis anterior muscle; the fibrosis control had no treatment, while the collagen-scaffolding group had a bone substitution matrix implanted. Animals were sacrificed at 21, 28, and 60 days post-procedure for histological, histochemical, immunohistochemical and histomorphometry analysis to evaluate muscle architecture and myogenic regenerative response. Significant changes in tissue architecture among groups, with a notable emphasis on the integration of the collagen scaffold, were demonstrated. This was also confirmed at the histomorphometry analysis, which found differences at the cross-sectional area, minor diameter and form factor values between groups The bone substitution matrix did not inhibit regeneration but promoted an abnormal one. This can be explained by the excessive formation of connective tissue, which led to the genesis of intramuscular tendons that may have interfered with the normal development of regenerative muscle fibers. The findings highlight the need for further investigation into the cellular mechanisms underlying skeletal muscle regeneration in response to implantable biomaterials.