Foreign Body Giant Cells Research Articles

Extreme Serum Titanium Concentration Induced by Acetabular Cup Failure: Unveiling a Unique Scenario of Titanium Alloy Debris Accumulation.

The majority of contemporary total hip arthroplasty (THA) implants are constructed from Ti alloys, which are generally believed to generate fewer adverse local tissue reactions (ALTRs) compared to CoCr alloys. This study presents a case of unusual primary THA failure where a substantial release of Ti alloy debris was observed. A 52-year-old active male underwent THA after post-traumatic aseptic necrosis of the femoral head in 2006. Seventeen years after the procedure, the patient presented with groin pain and a restricted range of motion. X-rays revealed the protrusion of the alumina ceramic head through the Ti6Al4V acetabular cup. Trace element analysis indicated significantly elevated levels of serum Ti, Al, and V. CT and MRI confirmed Ti alloy cup failure and a severe ALTR. During revision surgery, it was found that the worn-out ceramic head was in direct contact with the acetabular cup, having protruded through a central hole it had created over time. No acetabular liner was found. Histological analysis of his tissue samples showed wear-induced synovitis with areas of multinucleated foreign body giant cells and the accumulation of numerous metal particles but no acute inflammatory response. Six months after the revision THA, the patient has experienced favourable outcomes. This case provides an instructive illustration for studying the consequences of the substantial release of Ti alloy debris from orthopedic implants.

Tissue-engineered and autologous pericardium in congenital heart surgery: comparative histopathological study of human vascular explants.

The goal of this histological study was to assess the biocompatibility of vascular patches used in the repair of congenital heart defects. We examined tissue-engineered bovine (n = 7) and equine (n = 7) patches and autologous human pericardium (n = 7), all explanted due to functional issues or follow-up procedures. Techniques like Movat-Verhoeff, von Kossa and immunohistochemical staining were used to analyse tissue composition, detect calcifications and identify immune cells. A semi-quantitative scoring system was implemented to evaluate the biocompatibility aspects, thrombus formation, extent of pannus, inflammation of pannus, cellular response to patch material, patch degradation, calcification and neoadventitial inflammation. We observed distinct material degradation patterns among types of patches. Bovine patches showed collagen disintegration and exudate accumulation, whereas equine patches displayed edematous swelling and material dissolution. Biocompatibility scores were lower in terms of cellular response, degradation and overall score for human autologous pericardial patches compared to tissue-engineered types. The extent of pannus formation was not influenced by the type of patch. Bovine patches had notable calcifications causing tissue hardening, and foreign body giant cells were more frequently seen in equine patches. Plasma cells were frequently detected in the neointimal tissue of engineered patches. Our results confirm the superior biocompatibility of human autologous patches and highlight discernible variations in the changes of patch material and the cellular response to patch material between bovine and equine patches. Our approach implements the semi-quantitative scoring of various aspects of biocompatibility, facilitating a comparative quantitative analysis across all types of patches, despite their inherent differences.

Decoding the "Fingerprint" of Implant Materials: Insights into the Foreign Body Reaction.

Foreign body reaction (FBR) is a prevalent yet often overlooked pathological phenomenon, particularly within the field of biomedical implantation. The presence of FBR poses a heavy burden on both the medical and socioeconomic systems. This review seeks to elucidate the protein "fingerprint" of implant materials, which is generated by the physiochemical properties of the implant materials themselves. In this review, the activity of macrophages, the formation of foreign body giant cells (FBGCs), and the development of fibrosis capsules in the context of FBR are introduced. Additionally, the relationship between various implant materials and FBR is elucidated in detail, as is an overview of the existing approaches and technologies employed to alleviate FBR. Finally, the significance of implant components (metallic materials and non-metallic materials), surface CHEMISTRY (charge and wettability), and physical characteristics (topography, roughness, and stiffness) in establishing the protein "fingerprint" of implant materials is also well documented. In conclusion, this review aims to emphasize the importance of FBR on implant materials and provides the current perspectives and approaches in developing implant materials with anti-FBR properties.

Intersection of Immunity, Metabolism, and Muscle Regeneration in an Autoimmune-Prone MRL Mouse Model.

Due to the limited capacity of mammals to regenerate complex tissues, researchers have worked to understand the mechanisms of tissue regeneration in organisms that maintain that capacity. One example is the MRL/MpJ mouse strain with unique regenerative capacity in ear pinnae that is absent from other strains, such as the common C57BL/6 strain. The MRL/MpJ mouse has also been associated with an autoimmune phenotype even in the absence of the mutant Fas gene described in its parent strain MRL/lpr. Due to these findings, the differences between the responses of MRL/MpJ versus C57BL/6 strain are evaluated in volumetric muscle injury and subsequent material implantation. One salient feature of the MRL/MpJ response to injury is robust adipogenesis within the muscle. This is associated with a decrease in M2-like polarization in response to biologically derived extracellular matrix scaffolds. In pro-fibrotic materials, such as polyethylene, there are fewer foreign body giant cells in the MRL/MpJ mice. As there are reports of both positive and negative influences of adipose tissue and adipogenesis on wound healing, this model can provide an important lens to investigate the interplay between stem cells, adipose tissue, and immune responses in trauma and material implantation.

Omental coating attenuates implant-induced foreign body reaction in rats.

The objective of this study is to clarify whether the omental coating can effectively attenuate foreign body reaction (FBR) induced by implanted materials. Male Sprague-Dawley rats were injected with polydextran particle slurry intraperitoneally to activate the omentum. 7 days later, polyether polyurethane sponge discs were implanted subcutaneously on each side of the rat's back as the foreign implants to induce FBR. The next day, omental transposition were performed. The disc on the left side of each rat's back was wrapped with omental flap (omental group); the disc on the right side was untreated (control group). All discs were removed 21 days after implantation and assessed by determining the components of the fibrovascular tissue (angiogenesis, inflammation, foreign body giant cells (FBGCs) aggregation and fibrogenesis). In implants in omental group, micro vessel density (MVD), Hemoglobin (Hb) content and VEGF levels (pro-angiogenic cytokine) were increased when compared with implants from control group. Inflammatory parameters (IL-1β; macrophage accumulation-NAG activity; neutrophil accumulation- MPO levels) were decreased in implants after omental coating. Also, collagen deposition, fibrous capsule thickness, and FBGCs decreased in implants from omental group. However, intra-implant levels of TNF-α and TGF-β1 were not different after omental coating. Our findings showed for the first time that the omental coating around the implants attenuate the adverse FBR, it may be critical in developing new strategies to control FBR and improve the function and performance of the implanted materials.

Cellular and microenvironmental cues that promote macrophage fusion and foreign body response.

During the foreign body response (FBR), macrophages fuse to form foreign body giant cells (FBGCs). Modulation of FBGC formation can prevent biomaterial degradation and loss of therapeutic efficacy. However, the microenvironmental cues that dictate FBGC formation are poorly understood with conflicting reports. Here, we identified molecular and cellular factors involved in driving FBGC formation in vitro. Macrophages demonstrated distinct fusion competencies dependent on monocyte differentiation. The transition from a proinflammatory to a reparative microenvironment, characterised by specific cytokine and growth factor programmes, accompanied FBGC formation. Toll-like receptor signalling licensed the formation of FBGCs containing more than 10 nuclei but was not essential for cell-cell fusion to occur. Moreover, the fibroblast-macrophage crosstalk influenced FBGC development, with the fibroblast secretome inducing macrophages to secrete more PDGF, which enhanced large FBGC formation. These findings advance our understanding as to how a specific and timely combination of cellular and microenvironmental factors is required for an effective FBR, with monocyte differentiation and fibroblasts being key players.

The Implant-Induced Foreign Body Response Is Limited by CD13-Dependent Regulation of Ubiquitination of Fusogenic Proteins.

Implanted medical devices, from artificial heart valves and arthroscopic joints to implantable sensors, often induce a foreign body response (FBR), a form of chronic inflammation resulting from the inflammatory reaction to a persistent foreign stimulus. The FBR is characterized by a subset of multinucleated giant cells (MGCs) formed by macrophage fusion, the foreign body giant cells (FBGCs), accompanied by inflammatory cytokines, matrix deposition, and eventually deleterious fibrotic implant encapsulation. Despite efforts to improve biocompatibility, implant-induced FBR persists, compromising the utility of devices and making efforts to control the FBR imperative for long-term function. Controlling macrophage fusion in FBGC formation presents a logical target to prevent implant failure, but the actual contribution of FBGCs to FBR-induced damage is controversial. CD13 is a molecular scaffold, and invitro induction of CD13KO bone marrow progenitors generates many more MGCs than the wild type, suggesting that CD13 regulates macrophage fusion. In the mesh implant model of FBR, CD13KO mice produced significantly more peri-implant FBGCs with enhanced TGF-β expression and increased collagen deposition versus the wild type. Prior to fusion, increased protrusion and microprotrusion formation accompanies hyperfusion in the absence of CD13. Expression of fusogenic proteins driving cell-cell fusion was aberrantly sustained at high levels in CD13KO MGCs, which we show is due to a novel CD13 function, to our knowledge, regulating ubiquitin/proteasomal protein degradation. We propose CD13 as a physiologic brake limiting aberrant macrophage fusion and the FBR, and it may be a novel therapeutic target to improve the success of implanted medical devices. Furthermore, our data directly implicate FBGCs in the detrimental fibrosis that characterizes the FBR.

Releasable, Immune-Instructive, Bioinspired Multilayer Coating Resists Implant-Induced Fibrosis while Accelerating Tissue Repair.

Implantable biomaterials trigger foreign body reactions (FBRs), which reduces the functional life of medical devices and prevents effective tissue regeneration. Although existing therapeutic approaches can circumvent collagen-rich fibrotic encapsulation secondary to FBRs, they disrupt native tissue repair. Herein, a new surface engineering strategy in which an apoptotic-mimetic, immunomodulatory, phosphatidylserine liposome (PSL) is released from an implant coating to induce the formation of a macrophage phenotype that mitigates FBRs and improves tissue healing is described. PSL-multilayers constructed on implant surfaces via the layer-by-layer method release PSLs over a 1-month period. In rat muscles, poly(etheretherketone) (PEEK), a nondegradable polymer implant model, induces FBRs with dense fibrotic scarring under an aberrant cellular profile that recruits high levels of inflammatory infiltrates, foreign body giant cells (FBGCs), scar-forming myofibroblasts, and inflammatory M1-like macrophages but negligible amounts of anti-inflammatory M2-like phenotypes. However, the PSL-multilayer coating markedly diminishes these detrimental signatures by shifting the macrophage phenotype. Unlike other therapeutics, PSL-multilayered coatings also stimulate muscle regeneration. This study demonstrates that PSL-multilayered coatings are effective in eliminating FBRs and promoting regeneration, hence offering potent and broad applications for implantable biomaterials.

Itaconate and citrate releasing polymer attenuates foreign body response in biofabricated cardiac patches

Application of cardiac patches to the heart surface can be undertaken to provide support and facilitate regeneration of the damaged cardiac tissue following ischemic injury. Biomaterial composition is an important consideration in the design of cardiac patch materials as it governs host response to ultimately prevent the undesirable fibrotic response. Here, we investigate a novel patch material, poly (itaconate-co-citrate-co-octanediol) (PICO), in the context of cardiac implantation. Citric acid (CA) and itaconic acid (ITA), the molecular components of PICO, provided a level of protection for cardiac cells during ischemic reperfusion injury in vitro. Biofabricated PICO patches were shown to degrade in accelerated and hydrolytic conditions, with CA and ITA being released upon degradation. Furthermore, the host response to PICO patches after implantation on rat epicardium in vivo was explored and compared to two biocompatible cardiac patch materials, poly (octamethylene (anhydride) citrate) (POMaC) and poly (ethylene glycol) diacrylate (PEGDA). PICO patches resulted in less macrophage infiltration and lower foreign body giant cell reaction compared to the other materials, with corresponding reduction in smooth muscle actin-positive vessel infiltration into the implant region. Overall, this work demonstrates that PICO patches release CA and ITA upon degradation, both of which demonstrate cardioprotective effects on cardiac cells after ischemic injury, and that PICO patches generate a reduced inflammatory response upon implantation to the heart compared to other materials, signifying promise for use in cardiac patch applications.

Xanthogranulomatous Osteomyelitis: Two Rare Cases Report

INTRODUCTION: Xanthogranulomatous osteomyelitis (XO) is a rare chronic inflammatory lesion that is histologically characterized by the presence of foamy histiocytes and plasma cells (1-8). Radiologic and gross examinations can mimic malignancy (9), so carful workup and definitive diagnosis should be made by histopathologic evaluation. Case Report: There are two rare cases being reported here; the first one is a 21-year-old male who presented with chronic pain and swelling of upper leg for one year. He has history of healed traumatic fracture of fibula 7 years ago. Radiological examination revealed highly suspicious radio opaque lesions of upper fibula. The second case is a 30 years old female, presented with pain and swelling of wrist for six months with clinical suspicion of Ewing sarcoma. Radiological examination revealed highly suspicious radio opaque, lytic lesions of lower radius. Biopsy of both lesions were done. Microscopic examination showed marked chronic inflammatory cells infiltration mainly foamy histiocytes and lymphoid cells with many foreign body giant cells. No evidence of tuberculosis or malignancy. Conclusion: As these lesions were clinically highly suspicious of malignancy or associated with other diseases, so proper diagnostic roles in xanthogranulomatous osteomyelitis should include histopathological examination in order to rule out any malignant conditions of the bone.

Chronic tophaceous gout – A case report

Gout is an inflammatory arthritis associated with functional impairment and impact on quality of life. It arises when the tissues are supersaturated with urate leading to the formation of mono sodium urate crystals in and around the joints. This causes an inflammatory cascade resulting in secretion of several proinflammatory cytokines and neutrophil recruitment into the joint.A 60 years old male patient presented with complaints of swelling in the posterior aspect of left elbow since 2 years and pain since 15 days. Examination revealed soft tissue swellings in multiple joints including metatarsophalangeal joint. Renal function tests show increased Uric acid (8.6mg/dl). On Gross examination, we received fibrofatty mass measuring 3.5x1.5x1 cm. Cut-section showed white flakes ? Calcifications. On microscopy, sections studied show fibrocollagenous tissue with several tophi made up of pink eosinophilic material surrounded by foreign body giant cell reaction and lymphocytes. There are several cystic spaces filled with calcareous debris.Hyperuricemia is the key risk factor for gout and is considered prerequisite for mono sodium urate crystal formation. Urate under excretion through kidney is the major mechanism for hyperuricemia. Tophus formation is the cardinal feature of advanced gout.

Innate immunity response of zafirlukast treated-tilapia during foreign body inflammation

There is limited knowledge regarding the blockade of cysteinyl leukotriene receptors (CysLTRs) and their effects in teleost fish. The present study investigated the effects of Zafirlukast, antagonist of CysLTR1 receptor, on the foreign body inflammatory reaction in Nile tilapia (Oreochromis niloticus). Zafirlukast-treated tilapia demonstrated a decrease in the formation of multinucleated foreign body giant cells and Langhans cells on the round glass coverslips implanted in the subcutaneous tissue, along with a significant reduction in white blood cell counts and decreased production of reactive oxygen species. There was an increase in serum levels of α2-macroglobulins, as well as a decrease in ceruloplasmin and haptoglobin. Zafirlukast treatment led to a significant decrease in the area of splenic melanomacrophage centers and a reduction in the presence of lipofuscin. These findings highlight the potential anti-inflammatory effects of zafirlukast treatment in tilapia and indicate its action on CysLTR1 receptor, modulating the innate immune response of tilapia during the foreign body reaction. The comprehension of chronic inflammation mechanisms in fish has become increasingly relevant, especially concerning the utilization of biomaterials for vaccine and drug delivery.

Oxidation-treated carbon nanotube yarns accelerate neurite outgrowth and induce axonal regeneration in peripheral nerve defect

Carbon nanotubes (CNTs) have the potential to promote peripheral nerve regeneration, although with limited capacity and foreign body reaction. This study investigated whether CNTs hydrophilized by oxidation can improve peripheral nerve regeneration and reduce foreign body reactions and inflammation. Three different artificial nerve conduit models were created using CNTs treated with ozone (O group), strong acid (SA group), and untreated (P group). They were implanted into a rat sciatic nerve defect model and evaluated after 8 and 16 weeks. At 16 weeks, the SA group showed significant recovery in functional and electrophysiological evaluations compared with the others. At 8 weeks, histological examination revealed a significant increase in the density of regenerated neurofilament and decreased foreign body giant cells in the SA group compared with the others. Oxidation-treated CNTs improved biocompatibility, induced nerve regeneration, and inhibited foreign-body reactions.

In vivo biocompatibility testing of nanoparticle-functionalized alginate–chitosan scaffolds for tissue engineering applications

Background: There is a strong interest in designing new scaffolds for their potential application in tissue engineering and regenerative medicine. The incorporation of functionalization molecules can lead to the enhancement of scaffold properties, resulting in variations in scaffold compatibility. Therefore, the efficacy of the therapy could be compromised by the foreign body reaction triggered after implantation.Methods: In this study, the biocompatibilities of three scaffolds made from an alginate–chitosan combination and functionalized with gold nanoparticles (AuNp) and alginate-coated gold nanoparticles (AuNp + Alg) were evaluated in a subcutaneous implantation model in Wistar rats. Scaffolds and surrounding tissue were collected at 4-, 7- and 25-day postimplantation and processed for histological analysis and quantification of the expression of genes involved in angiogenesis, macrophage profile, and proinflammatory (IL-1β and TNFα) and anti-inflammatory (IL-4 and IL-10) cytokines.Results: Histological analysis showed a characteristic foreign body response that resolved 25 days postimplantation. The intensity of the reaction assessed through capsule thickness was similar among groups. Functionalizing the device with AuNp and AuNp + Alg decreased the expression of markers associated with cell death by apoptosis and polymorphonuclear leukocyte recruitment, suggesting increased compatibility with the host tissue. Similarly, the formation of many foreign body giant cells was prevented. Finally, an increased detection of alpha smooth muscle actin was observed, showing the angiogenic properties of the elaborated scaffolds.Conclusion: Our results show that the proposed scaffolds have improved biocompatibility and exhibit promising potential as biomaterials for elaborating tissue engineering constructs.

Nasal Gouty Tophus

A 48-year-old, non-hypertensive, non diabetic man with uncontrolled gouty arthritis presented with a four-day swollen nasal mass. He was assessed to have a nasal abscess at the emergency room and was admitted for urgent management. Paranasal computed tomography (CT) scans showed a heterogeneously enhancing focus with areas of hypodensities in the nasal apex and dorsum extending into the right ala measuring 1.5 x 2.8 x 3.4 cm. with associated erosion of the cartilaginous part of the anterior nasal septum, soft tissue swelling and skin thickening in the nasal dorsum, nasal tip and right zygomatic region that was suspected to relate to an aggressive etiology. Tissue correlation was therefore recommended, and he underwent endoscopic-guided incision and drainage with biopsy and debridement of the nasal mass. The specimen submitted consisted of red to white, irregular, soft tissue fragments with an aggregate measurement of 1.5 x 1.5 x 0.5 cm. Microsections showed deposits of amorphous white to pink material with surrounding fibrosis and acute and chronic inflammatory cell infiltrates and foreign body giant cells. (Figures 1 and 2) Also seen in the background were fragments of sclerotic bone and bacterial colonies. These findings were consistent with gouty tophus with acute and chronic inflammation and bacterial colonization. The culture and sensitivity test of the nasal discharge showed growth of Enterobacter aerogenes (currently named Klebsiella aerogenes) which was identified by an automated mass spectrometry microbial identification system (VITEK® MS). Work-up also included uric acid levels which were within the reference interval at that time (6.57 mg/dL).

Effects of glass-ceramic produced by the sol-gel route in macrophages recruitment and polarization into bone tissue regeneration.

Effective bone substitute biomaterials remain an important challenge in patients with large bone defects. Glass ceramics produced by different synthesis routes may result in changes in the material physicochemical properties and consequently affect the success or failure of the bone healing response. To investigate the differences in the orchestration of the inflammatory and healing process in bone grafting and repair using different glass-ceramic routes production. Thirty male Wistar rats underwent surgical unilateral parietal defects filled with silicate glass-ceramic produced by distinct routes: BS - particulate glass-ceramic produced via the fusion/solidification route, and BG - particulate glass-ceramic produced via the sol-gel route. After 7, 14, and 21 days from biomaterial grafting, parietal bones were removed to be analyzed under H&E and Massons' Trichome staining, and immunohistochemistry for CD206, iNOS, and TGF-β. Our findings demonstrated that the density of lymphocytes and plasma cells was significantly higher in the BS group at 45, and 7 days compared to the BG group, respectively. Furthermore, a significant increase of foreign body giant cells (FBGCs) in the BG group at day 7, compared to BS was found, demonstrating early efficient recruitment of FBGCs against sol-gel-derived glass-ceramic particulate (BS group). According to macrophage profiles, CD206+ macrophages enhanced at the final periods of both groups, being significantly higher at 45 days of BS compared to the BG group. On the other hand, the density of transformation growth factor beta (TGF-β) positive cells on 21 days were the highest in BG, and the lowest in the BS group, demonstrating a differential synergy among groups. Noteworthy, TGF-β+ cells were significantly higher at 21 days of BG compared to the BS group. Glass-ceramic biomaterials can act differently in the biological process of bone remodeling due to their route production, being the sol-gel route more efficient to activate M2 macrophages and specific FBGCs compared to the traditional route. Altogether, these features lead to a better understanding of the effectiveness of inflammatory response for biomaterial degradation and provide new insights for further preclinical and clinical studies involved in bone healing.

CARD9-Mediated Macrophage Responses and Collagen Fiber Capsule Formation Caused by Textured Breast Implants.

An increasing number of women are undergoing breast implantation for cosmetic purposes or for reconstructive purposes after breast excision. The surface morphology of the breast implant is a key factor associated with the induction of capsule contraction. The effect of surface morphology on the inflammatory response after implant insertion remains unclear, however. The authors conducted comparative analyses to determine the effect of the textured and smooth surface morphology of silicone sheets. Each type of silicone sheet was inserted into the subcutaneous pocket below the panniculus carnosus in C57BL/6 mice and mice with genetic disruption of CARD9 , Dectin-1 , Dectin-2 , or Mincle . The authors analyzed collagen fiber capsule thickness, histologic findings, and macrophage inflammatory response, including transforming growth factor (TGF)-β synthesis. The authors found that textured surface morphology contributed to the formation of collagen fiber capsules and the accumulation of fibroblasts and myofibroblasts, and was accompanied by the accumulation of TGF-β-expressing macrophages and foreign-body giant cells. CARD9 deficiency attenuated collagen fiber capsule formation, macrophage responses, and TGF-β synthesis, although the responsible C-type lectin receptors remain to be clarified. These results suggest that CARD9 may have a strong impact on silicone sheet morphology through the regulation of macrophage responses. Silicone breast implants have been widely used for postmastectomy and cosmetic augmentation mammaplasty breast reconstruction. The authors sought to elucidate the surface morphology of the breast implant as one of the key factors associated with the formation of collagen fiber capsules. Therapeutic, V.

A novel in vivo model of ureteral fibrosis induced by calcium oxalate beads in C57BL/6J mice.

The global incidence of ureteroliths in humans is increasing, particularly posing a problem in developed countries. The most common stone type is calcium oxalate, which is associated with a high recurrence rate. In veterinary medicine, stones are the most common cause of ureteral obstruction in cats, accounting for 72-87% of cases. In cats, stones cause irreversible ureteral damage, necessitating stone treatment as well as ureteral therapy. However, the mechanisms underlying the ureteral damage caused by stones remain unclear. Therefore, this study aimed to create a mouse model suitable for studying the ureteral fibrosis caused by oxalate stones by artificially embedding calcium oxalate in the ureter. Pathological tissue analysis was used to compare normal ureters without ligation and ureters with sham or oxalate bead implantation. The ureters of the sham and oxalate bead groups showed granulation tissue formation, transitional epithelium exfoliation, and densely packed connective tissue in the proprietary and muscle layer regions. Particularly in the oxalate bead group, infiltration of degenerated neutrophils, presence of foreign body giant cells, and hyperplasia of the transitional epithelium were observed. The proportion of fibrosis was higher in the oxalate group than in the sham group. Overall, this mouse model created using oxalate bead implantation has the potential to efficiently induce ureteral obstruction. This mouse model is expected to be used for elucidating the molecular mechanisms of ureteral fibrosis and evaluating therapeutic drugs in future.

Idiopathic Scrotal Calcinosis: Surgical Treatment of a Rare Cutaneous Disorder

Idiopathic scrotal calcinosis is a rare, painless and benign disease characterized by the presence of multiple painless calcified nodules of the scrotum with no abnormalities of phosphocalcic metabolism. The main reason for consult among patients is the aesthetic discomfort. Histology shows basophilic calcium deposits in the scrotal dermis and calcified fibroids surrounded by foreign body giant cell granulomas. Treatment is based on surgical removal of the nodules. We report the case of a 27-year-old patient with no notable pathological history who consulted for multiple cystic nodular lesions of the scrotum, painless and non- infected, with no notion of previous trauma, evolving for 12 years. The patient underwent surgical removal of the scrotal nodules under local anesthesia. No recurrence was noted; the follow-up was one year. After a review of the literature, we discuss the pathogenic, clinical and therapeutic aspects of this poorly understood pathology.

A study of the histopathology of collagen fleece (TachoSil) patching of tunica albuginea in the rat penis and a literature review of penile graft materials in experimental animals.

A penile tunica defect may arise during surgery in patients with Peyronie's disease. Collagen fleece (TachoSil) has recently gained popularity in penile surgery to cover the tunica albuginea (TA) defect associated with clinical success. However, it is not known what the histological outcomes of these grafts are in the penis. We aimed to study the histopathology of the TachoSil graft in an experimental animal model for the regeneration of TA, inflammation, fibrosis, and the underlying cavernous tissue. Six adult male Sprague Dawley rats were used. The penis was degloved through a circumferential subcoronal incision. A longitudinal 1 mm × 10 mm defect was created at the base of the lateral aspect of the penis. A TachoSil patch (Takeda, Japan) was applied to the defect. The penile skin covering was then restored. At 2 months, the rat penis was excised and examined with hematoxylin, eosin, and trichrome stains. We conducted a literature review of penile grafts in animals for comparison. Rats weighed 369.2 gm (standard deviation: 31.5). At 2 months, all rats showed normal-looking penis with complete healing, no scaring, tethering, or gross inflammatory features. Histopathology of the patch site showed fibrosis, chronic inflammation, and foreign body giant cell reaction. There was no generation of a new TA, or new vascularity. No inflammatory or pathological reaction affected the underlying corpus cavernous tissue. One rat died on the 6th postoperative day. Postmortem showed massive multiorgan hemorrhage consistent with disseminated intravascular coagulopathy (DIC). Unlike some other reported grafts, there is no TA regeneration. TachoSil patching of penile TA defect forms a distinctive barrier against inflammation, protecting the underlying corpus cavernosum. However, no regeneration of the tunica defect is observed at 2 months. DIC is a potential complication of systemic absorption of TachoSil.