Dense Fibrous Connective Tissue Research Articles

Scalp Composite Tissue Transplantation for Repairing Upper Lip Defect: A Feasible Clinical Study.

The repair of upper lip defects is difficult and can result in asymmetry. The authors have developed a postauricular scalp composite tissue for the repair of upper lip defects. Herein, the authors, present the feasibility of scalp composite tissue grafts for repairing of upper lip defects. The authors conducted a retrospective study of 10 patients who underwent scalp composite tissue transplantation for upper lip repair. The surgical procedure consisted of the excision of skin lesions or scar tissue from the upper lip to prepare the recipient area, and then the scalp composite tissue was excised behind the ear and transplanted to the upper lip defect. The authors reviewed the photographs and clinical notes of these patients. The patients' self-reported satisfaction with the repair effect was assessed. Tissue sections and hematoxylin and eosin staining of the scalp composite tissues were performed. All patients successfully underwent lesion resection and scalp composite tissue transplantation to repair the wound. There was no necrosis of the scalp composite tissue in the early postoperative period. The lip wound healed completely within 2 weeks. The mean follow-up time was 16 months, ranging from 12 to 20 months. Histologic sections and hematoxylin and eosin staining showed that the scalp composite tissue had abundant capillaries and dense fibrous connective tissue. All 10 patients were satisfied with the clinical effect of the procedure. Scalp composite tissue transplantation is a viable method for repairing upper lip defects. The special histomorphological characteristics of the scalp provide the basis for clinical application. IV.

Targeted Therapy for Highly Desmoplastic and Immunosuppressive Tumor Microenvironment of Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a very poor prognosis. Despite advancements in treatment strategies, PDAC remains recalcitrant to therapies because patients are often diagnosed at an advanced stage. The advanced stage of PDAC is characterized by metastasis, which typically renders it unresectable by surgery or untreatable by chemotherapy. The tumor microenvironment (TME) of PDAC comprises highly proliferative myofibroblast-like cells and hosts the intense deposition of a extracellular matrix component that forms dense fibrous connective tissue, a process called the desmoplastic reaction. In desmoplastic TMEs, the incessant aberration of signaling pathways contributes to immunosuppression by suppressing antitumor immunity. This feature offers a protective barrier that impedes the targeted delivery of drugs. In addition, the efficacy of immunotherapy is compromised because of the immune cold TME of PDAC. Targeted therapy approaches towards stromal and immunosuppressive TMEs are challenging. In this review, we discuss cellular and non-cellular TME components that contain actionable targets for drug development. We also highlight findings from preclinical studies and provide updates about the efficacies of new investigational drugs in clinical trials.

Nail Telocytes: Identification, Potential Physiological Function, and Role in Pathology: A Reappraisal of the So-Called Onychofibroblasts/Onychodermis.

Some authors have suggested that the fibroblasts of the nail mesenchyme (onychofibroblasts) can be distinguished from skin fibroblasts by their high expression of CD10. My 2015 study documented the presence of a relatively sparse CD34+/CD10+ dendritic subpopulation in the dermis and hypodermis of the matrix. For some time now, my hypothesis has been that these interstitial dendritic mesenchymal cells of the matrix correspond to telocytes. Telocytes have been described as peculiar interstitial dendritic cells present in the mesenchymal tissue of numerous organs, including the skin, but their presence and characteristics in the nail unit have not been explored. This study was undertaken to more comprehensively investigate the existence and characteristics of nail telocytes. A series of 20 normal adult nail units were examined with a combination of morphological and immunohistochemical analyses. The matrix dermis contained a sparse subpopulation of CD34+/CD10+ elongated telocytes with a higher density in the lunular region and, at this distal level, a change in their immunohistochemical profile, resulting in a progressive loss of CD34 expression. The matrix hypodermis showed CD34+/CD10+ telocytes in their classical elongated aspect, which acquired, especially in the distal fibromyxoid area of the thumb, an oval to round morphology with multiple intracytoplasmic vacuoles. The characteristic dynamic immunophenotypic profile of the dermal telocytes with a progressive distal loss of the defining molecule CD34 was equally observed in the distal hypodermis. The nail bed dermis was thick with a dense fibrous connective tissue. A reticular network of CD34-/CD10+ telocytes was present in the superficial dermis of the proximal nail bed. The mesenchymal cells of the deep part of the proximal nail bed dermis and the entire distal nail bed dermis were CD34-/CD10-. The adult nail mesenchyme is composed of 3 microanatomically distinct regions. Only the thumb has a distal hypodermis rich in mucinous material. The population of telocytes is relatively sparse compared with the fibroblastic population of the entire nail mesenchyme. The concept of onychodermis/onychofibroblasts is not valid. Nail telocytes have a dynamic immunohistochemical profile depending on whether they are located proximally or distally. The CD34+/CD10+ profile correlates with the onychogenic epithelial region, while the CD34-/CD10+ profile correlates with a spatial rearrangement of the nail epidermal bed.

A comprehensive guide to western blotting for tendon research

Tendons are classified as dense fibrous connective tissue. This fibrous composition poses challenges in protein extraction, particularly hindering the application of Western blotting techniques. Because of these challenges, it becomes necessary to implement additional steps and specific solutions to attain success in this methodology with the tissue in question. The objective of this article is to provide a detailed protocol, elucidating each step, and making it easily replicable for researchers. The study focused on the Achilles tendons of Sprague-Dawley rats, emphasizing the need for a tailored approach in working with this tissue. By addressing the nuances of protein extraction from the dense and fibrous tendons, our protocol aims to facilitate the reproducibility of Western blotting experiments, contributing to a better understanding of this tissue.

Immunohistochemical and Histopathological Characterization of Spina Bifida Defect Tissues Removed After Prenatal and Postnatal Surgical Repair

Background: Myelomeningocele or spina bifida is an open neural tube defect that is characterized by protrusion of the meninges and the spinal cord through a deformity in the vertebral arch and spinous process. Myelomeningocele of post-natal tissue is well described; however, pre-natal tissue of this defect has no known previous histologic characterization. We compared the histology of different forms of pre-natal myelomeningocele and post-natal myelomeningocele tissue obtained via prenatal intrauterine and postnatal surgical repairs. Methods: Pre-and post-natal tissues from spina bifida repair surgeries were obtained from lipomyelomeningocele, myeloschisis, and myelomeningocele spina bifida defects. Tissue samples were processed for H&E and immunohistochemical staining (KRT14 and p63) to assess epidermal and dermal development. Results: Prenatal skin near the defect site develops with normal epidermal, dermal, and adnexal structures. Within the grossly cystic specimens, histology shows highly dense fibrous connective tissue with complete absence of a normal epidermal development with a lack of p63 and KRT14 expression. Conclusion: Tissues harvested from prenatal and postnatal spina bifida repair surgeries appear as normal skin near the defect site. However, cystic tissues consist of highly dense fibrous connective tissue with complete absence of normal epidermal development.

Results of ligation the internal iliac and ovarian arteries in the experiment

Objective: to study in an experiment on animals pathomorphological changes in the tissues of the uterus, appendages and blood vessels after ligation of the internal iliac and ovarian arteries.Materials and methods: An experiment was conducted with 6 mature pigs. Group I (n=3) consisted of intact pigs without surgery, group II (n=3) included animals with ligation of the internal iliac and ovarian arteries on both sides. 12 months after the operation, slaughter was performed and the organo-complex of the uterus with appendages and iliac vessels was taken for electron microscopic pathomorphological examination.Results: comparative results of the study of the uterus, appendages found that the normal structure of the mature uterus was preserved, there were no changes in the structure of the fallopian tubes, tissues and vessels of the ovaries. All changes were found in the area of ligation of the ovarian and internal iliac arteries, although the arteries retained their lumen, but were deformed and surrounded by dense fibrous connective tissue. Conclusion: ligation of the ovarian and internal iliac arteries with absorbable suture material causes only local changes. The sufficiency of collateral blood flow is confirmed by the absence of atrophy of the uterus, fallopian tubes and ovaries, as well as organ deformities.

Gelatin methacryloyl hydrogel with and without dental pulp stem cells for TMJ regeneration: An invivo study in rabbits.

In the last decade, tissue-engineering strategies for regenerating the temporomandibular joint (TMJ) have been investigated. This may be a promising strategy for the minimally invasive restoration of joint integrity. To evaluate whether dental pulp stem cells (DPSCs) loaded in a light-occured hydrogel made of gelatin methacryloyl (GelMA) enhance the regeneration of osteochondral defects in the rabbit TMJ. Defects were filled with GelMA alone (control group; n = 4) or filled with GelMA loaded with rabbit DPSCs (experimental group; n = 4), In one group, the TMJ capsule was opened without creating a defect (sham group; n = 2). The following micro-CT parameters were analysed: bone volume to total volume ratio (BV/TV%) and bone mineral density (BMD). Histological evaluation was performed to assess cartilage regeneration features. A semi-quantitative scoring system was also used to evaluate the defects. All groups had no statistical difference regarding the micro-CT parameters. The highest mean healing score was found for the experimental group. After 4 weeks, there were no signs of hydrogel in either group or no signs of inflammation in the adjacent tissues. The tissue formed in the defect was dense fibrous connective tissue. Adding DPSCs to GelMA did not provide a regenerative enhancement in TMJ osteochondral defects. This resulted in similar micro-CT parameters after 4 weeks of healing, with improved signs of subchondral bone regeneration but no cartilage regeneration.

Central odontogenic fibroma: A case report

The central odontogenic fibroma (COF) is a rare benign odontogenic mesenchymal tumour of jaw bone derived from the odontogenic ectomesenchyme. It is characterized by a fibrous mature stroma with variable number of strands or islands of inactive-looking odontogenic epithelium. The presented case is a 46 years old male complaining of asymptomatic mandibular bony swelling. Radiographically, the lesion is unilocular radiolucent, with root resorption and displacement of teeth. Histopathology showed dense fibrous connective tissue stroma, loosely arranged with spindle and stellate-shaped mesenchymal cells, inactive odontogenic epithelium island and osteoid tissue. In this case report, we also discuss about the types, pathogenesis, and recent concepts regarding COF.

Anatomical and Histological Study of the Upper Tarsus in Asian.

The aim of this study was to observe and analyze the anatomical and histological characteristics of the upper tarsus in Asian. A total of 15 Asians (14 adults, 1 child) were used. The sagittal sections with thickness of 3μm in the middle of the upper eyelid were prepared and stained with hematoxylin-eosin, Masson trichrome and anti-smooth muscle actin antibody staining, and then were observed and photographed under light microscopy. On the sagittal section, the upper end of the tarsus was connected with the Müller muscle and the part of the posterior layer of the levator aponeurosis; the lower end was the inflated part of the palpebral margin; the superficial surface was connected with the pretarsal fascia; and the deep surface was connected with Müller muscle aponeurosis and palpebral conjunctiva. Histologically, the tarsus was similar to the structure between dense fibrous connective tissue and cartilage, and its main structures include meibomian glands and its ducts, accessory lacrimal glands, glands of Moll, glands of Zeis, eyelash hair follicles, Riolan muscle, blood vessels, and collagen fibers. Through the observation of the tarsus of a child, compared with the adult specimen, the meibomian gland tissue was more abundant; the collagen fibers density was significantly lower and arranged orderly; the blood vessel density was significantly higher; α-SMA positive smooth muscle cells could be seen in the upper end of the tarsus and its superficial and deep surfaces. In this study, the internal and adjacent anatomical structures of the upper tarsus in Asians were observed under a microscope, and according to the histological characteristics, the tarsus was divided into 3 parts and 3 types. Through the preliminary analysis, the tarsus was likely to show different histological characteristics in different individuals and age groups of Asians. There was a certain correlation between the degree of meibomian gland atrophy, the degree of collagen fibrosis and the density of blood vessel in the tarsus.

Heterotopic Ossification Bone Formation in the Frontal Bones of an African Grey Parrot (Psittacus erithacus).

A 5-year-old, male African grey parrot (Psittacus erithacus) was presented with multiple, slow-growing, firm, bilateral masses around the dorsal orbital rims. Computer tomographic imaging revealed mild, incomplete bridging bone formation on the rostrodorsal aspects of the head. A moderate amount of smooth bone formation was identified at the rostrodorsal aspect to the left orbit, with minimal associated soft tissue swelling. Surgical biopsies were collected from the masses and histopathological analysis of the most rostral right mass showed well-differentiated bone, surrounded by dense fibrous connective tissue. Scattered, well-differentiated osteocytes were present within the bone. No evidence of neoplastic changes or infectious agents were identified. The histopathological changes were consistent with metaplastic bone formation. History obtained from the owner revealed recent head trauma, which likely induced the cranial heterotopic ossification in the African grey parrot.

Morphological and Functional Characteristics of the Microenvironment After Pleural Implantation of Biosynthetic Materials

The objective: to study morphological changes in tissues after implantation of a bioresorbable material synthesized on the basis of polylactide (PLA) and polycaprolactone (PCL) in various ratios.Subjects and Methods. Laboratory animals Chinchilla lanigera (n = 12) underwent intrapleural implantation with 2% PLA/PCL 1/1 and 4% PLA/PCL 1/3 materials. Morphometric assessment was carried out in14 and 28 weeks, the animals were withdrawn from the experiment by an anesthetic overdosing.Results. When studying tissues adjacent to the implant regardless of differences in its composition, similar morphological signs were observed. A fibrous capsule formed around the implants, and it was more pronounced in 4% of PLA/PCL 1/3. In the structure of the implants, we noted the growth of loose and dense unformed fibrous connective tissue with blood vessels with a significant replacement of the bioresorbable polymer material (by 2/3). Lymphocytes, plasma cells, single macrophages, and multinucleated cells were predominantly located at the implant/tissue interface. In all studied samples, no necrosis was observed in the implantation bed and surrounding tissue.Conclusion. The data obtained confirm the biosafety of biomaterials and demonstrate the potential for their use in surgical treatment of humans.

MICRO- AND ULTRAMICROSCOPIC STRUCTURE OF THE LEFT ATRIA-VENTRICULAR VALVULAR APPARATUS IN HUMAN AT THE MATURE AGE IN NORM

This article presents the morphological characteristics of the mitral valve of a normal heart of an adult at a mature age.The purpose of our investigation is to find out the peculiarities of the morphology of the structural components of the mitral valve apparatus of the heart of a person of mature age in the norm.Material and methods. The study was performed on 32 preparations of mitral valves of adult human hearts. A complex of morphological research methods was used: methods of light and electron microscopy, histochemical method.Results. With the use of a complex of morphological research methods, a study of the structural components of the mitral valve apparatus of a normal mature person was carried out and their histoarchitectonics was established at the micro- and sub-microscopic levels.Conclusions. The leaflets of the mitral valve are connective tissue plates covered with a single-layer flat epithelium - endothelium. The leaflets are formed by fibrous connective tissue of different density, as a result of which three layers are identified: spongy, fibrous and ventricular. Typical chordae tendineae in the form of connective tissue threads extend from the papillary muscles to the leaflets of the mitral valve and attach to their ventricular surface. The skeleton of chordae tendinea is formed by dense fibrous connective tissue. Striated cardiac muscle tissue is found in some chordae tendinea in the areas on the side of the papillary muscles. The papillary muscles are formed by the working fibers of cardiomyocytes, which form a kind of network due to branches and anastomoses. The working fibers of cardiomyocytes are accompanied by layers of loose fibrous connective tissue, which includes a large number of blood vessels.

A Case Report of Uterine Body Constriction Precluding Normal Parturition Leading to Dystocia in a Mare

A 13-year-old multiparous Quarter Horse mare was presented to the Michigan State University's, Large Animal Emergency service for dystocia. Clinical evaluation revealed a minimally dilated cervix on vaginal examination, with a palpable deceased fetus. Postmortem evaluation following owner-elected humane euthanasia revealed a circumferential, tan, fibrous band at the base of the uterine body that constricted the uterus and was adhered to the left and right ovaries. A routine histologic section of the incarcerating cord attached to the ovary consisted predominately of dense fibrous connective tissue, large blood vessels, and a central oviduct suggestive of a rent in the broad ligament. To the authors' knowledge, this is the first case report to describe uterine body constriction that precluded vaginal delivery of a fetus in a late gestation mare.

Morphological and histological study of the spleen in Hedgehog (Hemiechinus auritus)

The present study aimed to investigate the morphological description and histological structure of the spleen in Hedgehog (Hemiechinus auritus); the anatomical study revealed that spleen in Hedgehog was elongated, tongue-like shape, with blue red color. It is situated in the abdominal cavity in the left side of the stomach. The results of histological study revealed that the spleen was surrounded by a thick capsule composed of outer layer of mesothelial cells and an inner layer consist of dense fibrous connective tissue, contains collagen and elastic fibers with more smooth muscle fibers, trabeculae extend from dense fibrous connective tissue the capsule into the splenic parenchyma. The contained trabecular arteries, nerves and were composed mainly of connective tissue made of collagen, reticular and elastic fibers and more smooth muscle fibers. It is comprised of two functionally and morphologically distinct compartments, the red pulp and the white pulp. The white pulp was made of lymphatic nodules consists of the marginal zone forming the outermost edge of white pulp, the periarteriolar lymphatic sheeth (PALS), central arteries and germinal centers Containing the phagocytic and plasma cells and Retinae cells win lymphocytes of medium and small-sized. The present study revealed some of these terminate in the marginal sinus at the junction of the white pulp and the marginal zone, whereas others traverse the marginal zone to form the venous system of the red pulp, which named after the large, blood-filled sinuses. Histological examination also showed that the red pulp spleen in hedgehog composed from vascular tissue that contain pulp arteries, venous sinuses and splenic cords Within the spaces between the cords are megakaryocytes and blood cells. Results of the present study revealed that extramedullary hematopoiesis (EMH) a normal occurs of the splenic red pulp. Extramedullary hematopoiesis may include increased numbers of erythroid precursors, myeloid precursors, megakaryocytes

A rare case of Riedel's thyroiditis: Immunoglobulin G4-related thyroid disease

Abstract Introduction Riedel's thyroiditis is a rare thyroiditis in which normal thyroid tissue is replaced by dense fibrous connective tissue. Its etiology is not fully known. An autoimmune process is thought to exist. In this disease group, lymphoplasmocytic tissue infiltration, mostly consisting of IgG4 (+) plasma cells and small lymphocytes, is seen accompanying fibrosis. In our case, we presented a very rare case of Reidel's thyroiditis. Clinical Case We report the case of a 46-year-old woman who came to the general surgery department with an enlargement at the base of her neck. Among the patient's complaints were dysphonia, a feeling of pressure and pain in the neck. She had no history of thyroid disease. Laboratory findings; TSH 0.06 uIU/ml (0.27–4.2), fT3 2.69 pg/mL (2.3–4.5), fT4 1.81 ng/dl (0.93–1.70), crp 73.6 mg/l (0.0–5.0), sedimentation 90 mm/h (0–20), leukocytes 11.74 10^3/ul (4.49–12.68), absolute neutrophil count 9.22 10 ^3/ul (1.9–7.9). Trucut biopsy was performed with the preliminary diagnosis of malignancy due to the history of a mass growing in a short time on the neck of the patient. Pathology result; “Intense fibrosis increase, severe lymphoplasmacytic cell infiltration rich in IgG4 positive cells. Thyroid follicle epithelial cells with ck7, panck, pax8, thyroglobulin, ttf1 positive and cea, ck20, alk negative Intense plasma cells with CD38 have polyclonal staining with kappa and lambda, and IgG4/IgG ratio > 50%. In the background, cd3, pax5 and bcl2 and T cell-rich reactive inflammatory cells are accompanied. Obliterative vascular structures were noted in rust and elastic histochemical stains, and storiform fibrosis was observed in places on the ground. When histopathological and immunohistochemical findings are evaluated together, it is primarily compatible with IgG4-related disease/reidel thyroiditis.'' She was then referred to the endocrinology department. The serum IgG4 level was found to be above normal. She was started on steroid treatment with 64 mg daily methylprednisolone. A weekly control plan was made. In these controls, the steroid dose was gradually reduced. In the follow-up one week later, it was observed that the patient's CRP and sedimentation returned to normal values. There was also a decrease in enlargement in the neck area. In the third month of the treatment, the patient didn't want to continue the treatment. She did not visit our clinic for the next 3 months. Then, she came for the control after three months without treatment. Biochemistry and thyroid function tests were normal. The swelling in the neck area of the patient was completely gone. Conclusion Reidel's thyroiditis is a very rare disease with publications on the basis of case reports in the literature. Therefore, there are no broad-spectrum clinical studies. Clarity on treatment approaches was also not provided. We also benefited from case reports while managing our patient's treatment. We believe that our case will contribute to the literature for the same purpose.

Dynamic pathomorphological characteristics of the nasolacrimal duct in its stenosis

Pathological description of the process of stenosis of the nasolacrimal duct at its various stages. The material for the study was obtained from the wall of the nasolacrimal duct during surgery in 50 patients whose condition was attributed to the 1st, 2nd or 3rd clinical stage of dacryostenosis. The material was fixed in formalin and sent for pathohistological and immunohistochemical (IHC) studies. In the 1st stage, the integrity of the epithelium of the nasolacrimal duct was preserved, the density of goblet cells was reduced. Seromucinous glands were single in the lamina propria in the area of stenosis. Diffuse lymphoid-plasmacytic infiltration was observed along the periphery of the terminal sections of the glands and in the subepithelial zone. The infiltrate includes CD68+ tissue macrophages and CD20+ and CD3+ lymphocytes, with a predominance of B-lymphocytes over T-lymphocytes. In the 2nd stage, changes in the epithelial layer in the stenosis zone were detected. In the IHC study, only individual leukocytes were observed in these zones, and T cells were found mainly in the subepithelial zone, B cells - deeper, monocytes - evenly in all layers. In the adjacent zones, the picture of the infiltrate corresponded to the 1st stage. In the 3rd stage, fragments of the nasolacrimal duct wall were represented by dense fibrous connective tissue with pronounced atrophic changes, areas of squamous metaplasia or proliferation of the basal layer, goblet cells were not detected. There was no infiltrate in the area of stenosis during IHC study. In the cellular elements of the infiltrate in areas adjacent to the stenosis zone, CD20+ and CD3+ lymphocytes were present in equal proportions, the arrangement in layers corresponded to that of the 2nd stage. The results of the study showed that dacryostenosis is a progressive pathological process associated with the progredient development of chronic productive inflammation in the lacrimal ducts.

Human Dental Pulp Stem Cells Differentiate into Cementoid-Like-Secreting Cells on Decellularized Teeth Scaffolds.

Periodontitis is a common inflammatory disease that in some cases can cause tooth loss. Cementum is a mineralized tissue that forms part of the insertion periodontium and serves to fix the teeth to the alveolar bone. In addition, it acts as a reservoir of different growth and differentiation factors, which regulate the biology of the teeth. Cementogenesis is a complex process that is still under investigation and involves different factors, including dentin sialophosphoprotein (DSPP). In this work we studied the role of surface microtopography in the differentiation of human dental pulp stem cells (hDPSCs) into cementoid-like secreting cells. We cultured hDPSCs on decellularized dental scaffolds on either dentin or cementum surfaces. Cell morphology was evaluated by light and electron microscopy. We also evaluated the DSPP expression by immunohistochemistry. The hDPSCs that was cultured on surfaces with accessible dentinal tubules acquired an odontoblastic phenotype and emitted characteristic processes within the dentinal tubules. These cells synthesized the matrix components of a characteristic reticular connective tissue, with fine collagen fibers and DSPP deposits. The hDPSCs that was cultured on cementum surfaces generated a well-organized tissue consisting of layers of secretory cells and dense fibrous connective tissue with thick bundles of collagen fibers perpendicular to the scaffold surface. Intra- and intercellular deposits of DSPP were also observed. The results presented here reinforce the potential for hDPSCs to differentiate in vitro into cells that secrete a cementoid-like matrix in response to the physical stimuli related to the microtopography of contact surfaces. We also highlight the role of DSPP as a component of the newly formed matrix.

Sclerosing encapsulating peritonitis in a dog

Sclerosing encapsulating peritonitis (SEP) is a rare condition which consists of reactive fibrous tissue proliferation with mixed inflammatory infiltration within the abdominal cavity. The present report describes an additional case of SEP affecting a mixed-breed immature female dog presented with persistent vomiting, progressive weight loss, and ascites. Abdominal radiographic and ultrasonographic findings suggested abdominal neoformation resulting in gastric displacement, in addition ascitic fluid was evaluated and cytology showed large numbers of inflammatory effusion. An exploratory laparotomy was performed and were detected multiple thick peritoneal adhesions which restricted mobility of abdominal viscera. Biopsy specimens of these lesions were submitted for histopathological examination. Microscopically, the external serous surfaces of the abdominal organs were covered with dense fibrous connective tissue characterized by intense mature collagen deposition and moderate angiogenesis. The animal was euthanized due to poor prognosis and sent for necropsy. The clinical, imaging, gross and microscopic findings were compatible with SEP. Keywords: Neoformation; intestinal obstruction; peritoneal adhesions, chronic inflammation.

Clinicopathological and immunohistochemical features of solitary fibrous tumour: A case report

AbstractSolitary fibrous tumour (SFT) is an uncommon soft tissue lesion, and even rarer in the oral cavity, where it presents a similar clinical presentation to other lesions that affect the oral cavity. Due to its broad morphological spectrum, the histopathological diagnosis might be challenging and, for a definite diagnosis, the use of complementary tools is usually required, such as immunohistochemistry. We aimed to report a case of a 31‐year‐old man with an asymptomatic, slightly purplish nodule located on the dorsum of the tongue. The intraoral physical examination revealed the presence of a nodular exophytic lesion and fibrous consistency, measuring 0.9 cm. The histopathological examination revealed a proliferation of mesenchymal cells with variable morphology in a stroma consisting of dense fibrous connective tissue with areas of hyalinization, in addition to numerous vascular structures with a “staghorn‐shaped” appearance. Considering the unspecific histopathological features, we performed the immunohistochemistry technique, which revealed diffuse positivity for CD34, focal positivity for Bcl‐2 and negativity for S100. Therefore, combined clinical, morphological and immunohistochemical features enable the conclusive diagnosis of solitary fibrous tumour. We emphasize the importance of knowledge about the differential diagnosis of undifferentiated lesions that affect the soft tissues to distinguish SFT from other neoplasms and, thus, perform the most appropriate treatment.

8866 Vaginoplasty Using Lyophilized Nile Tilapia Fish Skin in Sex Reassignment Surgery in 35 Transgender Women

<h3>Study Objective</h3> describe the use of LNTFS (Lyophilized Nile Tilapia Fish Skin) as graft for the lining of the neovaginal canal in neovaginoplasty for transgender women. <h3>Design</h3> Transversal study from August 2019 to December 2020. <h3>Setting</h3> N/A. <h3>Patients or Participants</h3> 35 transgender women older than 18 years. <h3>Interventions</h3> First of all, a bilateral orchiectomy followed by ventrally urethra opening, creating a new urethral meatus and a mucosal flap that will be attached to the base of the clitoris. For the vaginal lining, a xenograft tube composed of penile skin plus LNTFS was previously constructed with the aid of a rigid mold. <h3>Measurements and Main Results</h3> Complications: 8 Introits small wound dehiscences, 3 vaginal shrinking, 1 rectal injury, 1 postoperative bleeding. Biopsies were performed 4 to 6 months after the procedure: sections of mucosa lined with non-keratinized stratified squamous epithelium, with dense fibrous connective tissue permeated by vascular neoformation. The depth and width of each neovagina ranged from 16 to 20 cm (average of 18.49 cm) and width ranges of 5 to 6 cm (average 5.8 cm). All the patients reported, after postoperative evaluation, excellent sensitivity outcomes and good aesthetic results, with the satisfactory appearance of the previously desired female genitalia, a good to an excellent self-lubricated vagina, sufficient for sexual intercourse. Indeed, sensitivity was self-reported as excellent and all of the patients had orgasms either with self-masturbations or penetration on an average of 6.14 weeks after postoperative evaluation, excellent sensitivity outcomes and good aesthetic results, with the satisfactory appearance of the previously desired female genitalia, a good to an excellent self-lubricated vagina, sufficient for sexual intercourse. Indeed, Sensitivity was self-reported as excellent and all of the patients had orgasms either with self-masturbations or penetration on an average of 6.14 weeks after surgery. <h3>Conclusion</h3> LNTFS is a biocompatible material that offers a good vaginal depth and also a moist, smooth, and self-lubricated vaginal canal.