Background: Histological and immunohistochemical analyses of adipose tissue are essential for evaluating the quality and functionality of lipoaspirates in regenerative medicine and fat grafting procedures. These methods provide insights into tissue viability, cellular subtypes, and extracellular matrix (ECM) composition—all factors influencing graft retention and clinical outcomes. Purpose: This scoping review aims to summarize the most commonly used staining methods and their applications in the histology and immunohistochemistry of adipose tissue. By exploring qualitative and quantitative markers, we seek to guide researchers in selecting the appropriate methodologies for addressing experimental and translational research. Methods: A systematic search was conducted using PubMed, Ovid, and the Cochrane Library databases from inception to 2024, employing Boolean operators (“lipoaspirate” OR “fat graft” OR “gauze rolling” OR “decantation” OR “coleman fat” OR “celt” OR “nanofat” OR “lipofilling” OR “human fat” AND “histol*”). Studies were included if they utilized histology or immunohistochemistry on undigested human adipose tissue or its derivatives. The inclusion criteria focused on peer-reviewed, English-language studies reporting quantitative and qualitative data on adipose tissue markers. Results: Out of 166 studies analyzed, hematoxylin–eosin (H&E) was the most frequently employed histological stain (152 studies), followed by Masson Trichrome and Sudan III. Immunohistochemical markers such as CD31, CD34, and perilipin were extensively used to distinguish stromal vascular fraction (SVF) cells, adipocytes, and inflammatory processes. Studies employing semiquantitative scoring demonstrated enhanced comparability, particularly for fibrosis, necrosis, and oil cyst evaluation. Quantitative analyses focused on SVF cell density, mature adipocyte integrity, and ECM composition. Methodological inconsistencies, particularly in preparation protocols, were observed in 25 studies. Conclusions: This review highlights the critical role of histological and immunohistochemical methods in adipose tissue research. H&E staining remains the cornerstone for general tissue evaluation in the clinical context, while specialized stains and immunohistochemical markers allow for detailed analyses of specific cellular and ECM components in experimental research. Standardizing preparation and evaluation protocols will enhance interstudy comparability and support advancements in adipose tissue-based therapies.

Background: Despite its increasing incidence and prevalence throughout Western countries, lipedema continues to be a very enigmatic disease, often misunderstood or misdiagnosed by the medical community and with an intrinsic pathology that is difficult to trace. The nature of lipedemic tissue is one of hypertrophic adipocytes and poor tissue turnover. So far, there are no identified pathways responsible, and little is known about the cell populations of lipedemic fat. Methods: Adipose tissue samples were collected from affected areas of both lipedema and healthy participants. For single-cell RNA sequencing analysis, the samples were dissociated into single-cell suspensions using enzymatic digestion and then encapsulated into nanoliter-sized droplets containing barcoded beads. Within each droplet, cellular mRNA was converted into complementary DNA. Complementary DNA molecules were then amplified for downstream analysis. Results: The single-cell RNA-sequencing analysis revealed three distinct adipocyte populations at play in lipedema. These populations have unique gene signatures which can be characterized as a lipid generating adipocyte, a disease catalyst adipocyte, and a lipedemic adipocyte. Conclusions: The single-cell RNA sequencing of lipedemic tissue samples highlights a triad of distinct adipocyte subpopulations, each characterized by unique gene signatures and functional roles. The interplay between these adipocyte subtypes offers promising insights into the complex pathophysiology of lipedema.

Background: Mechanical processing techniques are commonly employed to prepare adipose tissue for clinical applications in reconstructive and aesthetic procedures. However, their histological and immunohistochemical impact on adipose tissue remains incompletely characterized. Purpose: This systematic review aims to investigate the impact of mechanical processing on the histological and immunohistochemical properties of adipose tissue. Methods: A systematic search was conducted using PubMed, Ovid, and Cochrane Library databases, with publications up to December 2024, employing Boolean operators (“mechanically processed” OR “lipoaspirate” OR “fat graft” OR “gauze rolling” OR “decantation” OR “coleman fat” OR “celt” OR “nanofat” OR “lipofilling” OR “human fat”) AND (“histol*”). Included were English-language studies or studies with a recognized English translation which had been subject to peer review and reported quantitative or qualitative markers of mechanically processed human adipose tissue with histology or immunohistochemistry. Risk of Bias was assessed with the OHAT score. Results: A total of 15 studies (n = 15) were included. In 13 of 15 studies (87%), mechanically processed adipose tissue demonstrated an increased stromal vascular fraction (SVF) cell density compared to unprocessed fat. Twelve studies (80%) reported improved preservation of the extracellular matrix (ECM), while 11 studies (73%) observed a reduction in mature adipocytes. Immunohistochemical analyses in 10 studies (67%) revealed elevated expression of vascular markers (CD31, CD34) and perilipin. Adverse histological features such as oil cysts, fibrosis, and inflammatory infiltrates were reduced in 9 studies (60%). Considerable heterogeneity in processing techniques and staining protocols precluded meta-analysis. Conclusions: Mechanical processing of adipose tissue is associated with favorable histological and immunohistochemical profiles, including increased SVF cell density, improved ECM preservation, and reduced inflammatory and fibrotic features. These findings support the potential of mechanical processing to enhance graft quality; however, standardization of techniques and evaluation protocols is needed to strengthen clinical translation.

Background: Due to the high frequency of postoperative complications after body-contouring surgeries, the need for a unifying postoperative complication grading system that correlates with outcomes is of key importance. Here we therefore consider the application of the Clavien–Dindo classification to evaluate postoperative complications after body-contouring surgeries. Methods: A retrospective study on 602 patients who underwent body-contouring surgery between 2009 and 2015 at our institution was performed. The length of hospital stays, age, sex, follow-up visits, and postoperative complications were evaluated and classified using the Clavien–Dindo classification. Results: We raised a total of 672 body-contouring procedures on 602 patients (563 female, 39 male). According to the Clavien–Dindo System, the severity of postoperative complications following body-contouring procedures was significantly correlated with the duration of hospitalization (mean 5.8 ± 2.7 days) and the number of follow-up visits (mean 4.4 ± 4.7). Conclusions: The Clavien–Dindo classification offers a valid prediction for postoperative hospital stay and the number of follow-up visits after body-reshaping surgery. By becoming a validated and reliable grading system that correlates patients’ outcomes after body-contouring procedures, this classification has the potential to significantly improve patients’ healthcare and quality of life.

Background: For many years, advancements in hand joint replacement (JR) were relatively minor compared to those for large joints. However, the caution previously exercised due to high complication rates is gradually being replaced by the expanding use of JR therapies for small joints in the hand. Despite this progress, there is a lack of comprehensive data on the outcomes of hand JR and on the optimal infrastructure required to meet the growing demand for these therapies. Methods: This study examined trends and revision rates of JR for thumb carpometacarpal (CMC-1) and finger (MCP and PIP) joints in both inpatient and outpatient settings in Germany. Data from the Federal Statistical Office of Germany (Destatis) and the Central Institute for Statutory Health Insurance Physicians (ZI) were analyzed, focusing on the incidence, demographics, and outcomes of these procedures. Results: This study found a substantial national increase in prosthetic treatments specifically for CMC-1, with a 2.18-fold rise in the outpatient sector compared to a 1.65-fold increase in inpatient treatments. Despite this shift, 83.7% of JR procedures were still performed in an inpatient setting. Conclusions: The overall complication rates appear to be declining, suggesting that while the management of these procedures is shifting towards outpatient care, the quality remains stable.

Autoimmune-induced alopecia, such as alopecia areata, involves immune-mediated damage to hair follicles, leading to significant hair loss. Emerging therapies that stabilize hypoxia-inducible factor 1-alpha (HIF-1α) show promise in counteracting follicular degradation and supporting hair regrowth. This communication highlights the potential of iron chelators, specifically deferoxamine (DFO) and deferiprone (DFP), to stabilize HIF-1α by reducing iron availability, thereby promoting vascularization, cellular proliferation, and a regenerative environment in the hair follicle niche. Clinical trials with iron chelators demonstrated improvements in hair density, thickness, and elasticity, as well as a reduction in hair loss by up to 66.8% over six months. These findings underscore the therapeutic potential of iron chelators in autoimmune alopecia management. Future research should explore the synergistic use of iron chelators with immune-modulating therapies, positioning them as viable options in the evolving field of alopecia treatment.