Stratified Squamous Epithelium Research Articles

Histochemical analysis, smooth muscle immunolocalization and volumetric density of the elastic system fibres of the ostrich (Struthio camelus) phallus.

There are few scientific reports on the histology of the phallus of ratite birds. The aim of this study was to conduct a histochemical analysis to determine the distribution of smooth muscle cells and the volumetric density (Vv) of the fibres of the elastic system in the ostrich phallus. Adult ostriches, 14 months old, were used. The phalluses were fixed in Bouin's solution and then transferred to a buffered formalin solution. They were then processed using standard histological stains for paraffin and slices were obtained. The following techniques were performed: HE, Picrosirius red, Alcian Blue at pH 1.0 and 2.5. The Periodic acid-Schiff reagent and Weigert's Resorcin-Fuchsin with previous oxidation were performed. The M42 test system was used to quantify the elastic system fibres. For immunohistochemical analysis, an anti alpha smooth muscle actin monoclonal antibody was used. The surface of the phallus is covered by a non-keratinized stratified squamous epithelium, which becomes stratified cylindrical in the region of the spermatic sulcus. No glands associated with the connective tissue were observed. The Vv of the elastic system fibres was 4.75%. Smooth muscle cells were visualized only in the walls of blood vessels through immunostaining, with an absence in the lymphatic sinuses. Despite similarities with other birds, such as the presence of a fibrous external axis, a lymphatic core, and a spermatic groove, the ostrich phallus shows marked differences, including the absence of an elastic core, a non-keratinized lining epithelium, and the absence of glands throughout its extension.

3D sheep rumen epithelial structures driven from single cells in vitro

Ruminants play a vital economic role as livestock, providing high-quality protein for humans. At present, 3D-cultured ruminant abomasum and intestinal organoids have been successfully established to study host and pathogen interaction. The rumen is a unique digestive organ of ruminants that occupies 70% of the volume of the digestive tract and its microbiota can decompose lignocellulose to support animal growth. Here we report a method for culturing rumen epithelial organoids. We found that single rumen epithelial cells form self-organized 3D structures representative of typical stratified squamous epithelium, which is similar to rumen epithelium. EGF, Noggin, Wnt3a, IGF-1, and FGF-10 significantly enhanced the seeding efficiency of organoids. Moreover, the inclusion of CHIR-99021, A83-01, SB202190, and Y-27632 is crucial for organoid formation and maintenance. Importantly, we demonstrate that rumen epithelial cells retain their ability to form organoids after passage, cryopreservation, and resuscitation. The rumen epithelial organoids express rumen cell type-specific genes, uptake fatty acids, and generate 2D cultures. In summary, our data demonstrate that it is feasible to establish organoids from single rumen epithelial cells, which is a novel in vitro system that may reduce the use of experimental animals.

Histological and immunohistochemical studies of the fungiform and the circumvallate papillae through the life stages from 6- to 72-week-old Sprague-Dawley male rats.

Taste sensitivity decreases with age. Therefore, we investigated the histological and immunohistochemical changes in the receptive fields circumvallate papilla (CvP) and fungiform papilla (FfP) to explore the mechanism underlying age-related changes in taste sensitivity in 6- to 72-week-old rats. We analyzed papilla size, the thickness of the keratin layer of the papilla and stratified squamous epithelium, taste bud size, the keratin layer around the taste pores in the CvP and FfP, and the number and distribution of taste buds in the CvP coronal section. We further assessed the expression of marker proteins for Type II and III cells, phospholipase C subtype beta 2 (PLCβ2), and synaptosomal-associated protein 25 (SNAP-25). The cellular activity of these taste cells was examined through co-localization with the senescence cell marker protein-30 (SMP30). There were no differences in the number of taste bud sections in the CvP among the age groups. However, the size of the CvP increased and the density of the taste bud area in the CvP area decreased with increasing age. In contrast, the number of cells with co-expression of SMP30, PLCβ2, and SNAP-25 decreased with age. Furthermore, the morphological structures of the CvP, FfP, and taste buds in these regions changed with age, but not the overall taste bud number in the CvP coronal section. The decrease in cell count with co-expression of SMP30 and PLCβ2, or SNAP-25 may indicate reduced cellular functions of taste cells with aging.

Characterization of 3D organotypic epithelial tissues reveals tonsil-specific differences in tonic interferon signaling.

Three-dimensional (3D) culturing techniques can recapitulate the stratified nature of multicellular epithelial tissues. Organotypic 3D epithelial tissue culture methods have several applications, including the study of tissue development and function, drug discovery and toxicity testing, host-pathogen interactions, and the development of tissue-engineered constructs for use in regenerative medicine. We grew 3D organotypic epithelial tissues from foreskin, cervix, and tonsil-derived primary cells and characterized the transcriptome of these in vitro tissue equivalents. Using the same 3D culturing method, all three tissues yielded stratified squamous epithelium, validated histologically using basal and superficial epithelial cell markers. The goal of this study was to use RNA-seq to compare gene expression patterns in these three types of epithelial tissues to gain a better understanding of the molecular mechanisms underlying their function and identify potential therapeutic targets for various diseases. Functional profiling by over-representation and gene set enrichment analysis revealed tissue-specific differences: i.e., cutaneous homeostasis and lipid metabolism in foreskin, extracellular matrix remodeling in cervix, and baseline innate immune differences in tonsil. Specifically, tonsillar epithelia may play an active role in shaping the immune microenvironment of the tonsil balancing inflammation and immune responses in the face of constant exposure to microbial insults. Overall, these data serve as a resource, with gene sets made available for the research community to explore, and as a foundation for understanding the epithelial heterogeneity and how it may impact their in vitro use. An online resource is available to investigate these data (https://viz.datascience.arizona.edu/3DEpiEx/).

Fence Technique: Reconstruction on the Aesthetic Zone after Cyst Enucleation—Case Report

Odontogenic cysts can lead to bone destruction that can hamper the dental implant placement in the ideal 3D position. Different biomaterials and techniques that allow bone regeneration are described in the literature, each with its advantages and disadvantages. This clinical case with 18 months of follow-up aims to show the enucleation of an odontogenic cyst following the guided bone regeneration with the fence technique, which allows the placement of the dental implants in the ideal 3D position, reducing morbidity and the number of surgeries. It involved a fifty-year-old male patient with a cyst in the second sextant who needed implant rehabilitation. During the first surgery, the odontogenic cyst (proven by histological analysis where there was reported a non-keratinized stratified squamous epithelium) was enucleated and a guided bone regeneration using the fence technique was performed. The fence technique combines the xenograft, the collagen membrane and an osteosynthesis plate that is molded and fixed to the intervention area to ensure sufficient space for bone tissue regeneration. After six months, two dental implants were placed in the region of tooth 11 and 21, then rehabilitated nine weeks later. The fence technique guaranteed the recovery of the bone morphology and the placement of the dental implants in the ideal 3D position. This technique allows for the handling of complex cases, avoiding the need of autologous bone.

Age-related Changes in Rat Tongue

The effects of ageing on the oral mucosa are believed to be relatively small. The purpose of this study was to identify morphological changes observed in rat tongue during ageing in 20-day-old, 3-month-old, 12-month-old, 28-month-old, and 48-month-old rats. Age-related changes in the thickness of the epithelium and lamina propria, the density of the elastic fibres and the number of mast cells were histomorphometrically analyzed. In 20-day-old rats, the stratified squamous epithelium and lamina propria thicknesses were thinnest, whereas with age, epithelial thickness reached its greatest thickness in 48-month-old rats and lamina propria thickness was most noticeable in 12-month-old rats. The arrangement and distribution of elastic fibres were disrupted in the lamina propria with ageing. The density of elastic fibres in lamina propria was lowest in 20-day-old rats, while in 12-month-old rats they reached their highest density, and then decreased sharply again in older rats. The number of mast cells per unit area was lowest in 20-day-old rats, reaching its highest number in 12-month-old rats and remaining high in older animals. In conclusion, with age, there was a moderate positive correlation and a statistically significant increase in tongue epithelial thickness, as well as a significant thickening of the lamina propria and an increase in the number of mast cells. The density of the elastic fibres in lamina propria decreased, but no negative correlation was observed with ageing.

Mammalian esophageal stratified tissue homeostasis is maintained distinctively by the epithelial pluripotent p63+Sox2+ and p63-Sox2+ cell populations.

Self-renewing, damage-repair and differentiation of mammalian stratified squamous epithelia are subject to tissue homeostasis, but the regulation mechanisms remain elusive. Here, we investigate the esophageal squamous epithelial tissue homeostasis in vitro and in vivo. We establish a rat esophageal organoid (rEO) in vitro system and show that the landscapes of rEO formation, development and maturation trajectories can mimic those of rat esophageal epithelia in vivo. Single-cell RNA sequencing (scRNA-seq), snapshot immunostaining and functional analyses of stratified "matured" rEOs define that the epithelial pluripotent stem cell determinants, p63 and Sox2, play crucial but distinctive roles for regulating mammalian esophageal tissue homeostasis. We identify two cell populations, p63+Sox2+ and p63-Sox2+, of which the p63+Sox2+ population presented at the basal layer is the cells of origin required for esophageal epithelial stemness maintenance and proliferation, whereas the p63-Sox2+ population presented at the suprabasal layers is the cells of origin having a dual role for esophageal epithelial differentiation (differentiation-prone fate) and rapid tissue damage-repair responses (proliferation-prone fate). Given the fact that p63 and Sox2 are developmental lineage oncogenes and commonly overexpressed in ESCC tissues, p63-Sox2+ population could not be detected in organoids formed by esophageal squamous cell carcinoma (ESCC) cell lines. Taken together, these findings reveal that the tissue homeostasis is maintained distinctively by p63 and/or Sox2-dependent cell lineage populations required for the tissue renewing, damage-repair and protection of carcinogenesis in mammalian esophagi.

Orofacial Manifestations in a Middle-Aged Woman with Cowden Syndrome: A Case Image.

A 56-year-old Brazilian woman sought dental care, presenting with multiple asymptomatic papillomatous lesions with a coalescent pattern and intermingled cobblestone-like clefts along the alveolar ridge and marginal and attached gingivae. Multiple whitish papules were also observed on the face, neck, and limbs. Incisional biopsies of these lesions were performed. Microscopically, the skin lesion revealed epithelial clear cells and intraepithelial keratinization with areas of orthokeratosis, while the gingival lesions showed a parakeratinized stratified squamous epithelium with collagenous connective tissue. These features were consistent with those of a trichilemmoma and fibroepithelial hyperplasia, respectively. This article illustrates a case of Cowden syndrome (CS), a rare multisystem genetic condition in which both cutaneous and mucosal tissues were affected. Fewer than 40 cases of CS with oral involvement affecting middle-aged adults have been documented hitherto.

Novel pathologic findings and viral antigen distribution in cattle and buffalo calves naturally infected with Foot-and-Mouth disease virus

The Foot-and-Mouth disease is highly contagious acute viral disease of livestock inflicting huge economic loss to the farmers. The limited knowledge regarding the pathological lesions vis-a-vis distribution of the FMDV in lesser explored endocrine glands and important vital organs other than the target organs of infected calves prompted us to take the present investigation to have detailed insight into the pathogenesis. The systematic necropsy of 37 dead calves (cattle-28 and buffalo-9) was conducted, and thin representative tissue pieces from the affected organs were collected in 10% neutral buffered formalin (NBF) for pathological and immunohistochemical investigations. The genomic detection and its serotyping were done by RT-PCR and multiplex-PCR, respectively. Necropsy examination in all cases showed myocardial lesions resembling ‘tigroid heart appearance’. Other organ specific lesions include vesiculo-ulcerative stomatitis, edema of the lungs, petechial hemorrhages, edema of the endocrines, and gastroenteritis. Histopathological examination showed varying sizes of vesicles and ulcerations in stratified squamous epithelium of the tongue, acute necrotizing myocarditis, lymphoid depletion in lymphoid tissues, hepatitis, pancreatitis, thymic hyperplasia, thyroiditis, adrenitis, and enteritis. Positive immunolabeling for viral antigens was observed in endocrine glands, lymphoid organs, lungs, liver, kidneys, and intestine, in addition to other typical locations. The thyroid, adrenal glands, and pancreas, in addition to the tongue and heart, are the tissue of choice for sampling in the field during epidemics. Further, the viral genome and serotype A was confirmed in the affected tissues. This study provides insights into novel tissue tropism and pathogenesis in young calves naturally infected with FMDV.

Histomorphological study of tongue in Indigenous peacock (Pavo cristatus)

The current study aimed to examine the histomorphological features of the oral salivary ducts and the peacock tongue (Pavo cristatus) of this species. In this study, eight healthy adult peacocks were used after collecting them from a commercial market in Baghdad to investigate and describe the tongue in these bird species. After being euthanized, they were killed by cutting off the major neck blood vessels and bleeding until death; the tongue was identified. The tongue was the sharp end, elongated, somewhat triangular, and measured 8.2 mm. The apex, trunk, and base are its three sections. There are 4 to 5 layers of big conical papillae on the area where the root and body converge. Without gustatory papillae, the dense keratinized epithelium stratified squamous epithelia that lined the dorsal surface and were sparse on the ventral surfaces. The body and tongue root contain cells of the epithelium. It was supported by hyaline cartilage as a short plate. Lingual salivary glands situated anterior and posterior are superficial branch tubuloalveolar glands. This research was conducted at the University of Baghdad/ College of Veterinary Medicine in the Anatomy and Histology Department. Our result concluded that modifying the bird tongue, papillae distribution, and mucosa epithelium histological features is mainly restricted to feeding types that also have similarities with other avian species. Keywords: peacock, tongue, lingual papillae, keratinized epithelium

Intravesical urachal cyst masquerading as a bladder malignancy: a case report

BackgroundUrinary bladder masses in children are extremely rare. Certain benign conditions (e.g., ureterocele) can mimic malignant bladder masses. In this report, we present a unique case of a urachal cyst masquerading as a bladder malignancy. Unlike the typical location of urachal cysts along the course of the urachal tract, the cyst in this case was unexpectedly situated within the urinary bladder, leading to diagnostic difficulties.Case presentationA 2-year-old Bahraini boy presented with hematuria and dysuria for 2 weeks. There was no history of fever, abdominal pain, or vomiting. Physical examination yielded normal findings. Urinalysis showed numerous red blood cells and revealed positive results for nitrites and leukocyte esterase. Abdominal ultrasound showed a well-defined soft tissue lesion with internal vascularity located at the apex of the urinary bladder. Subsequently, magnetic resonance imaging demonstrated a thick-walled cystic structure arising from the anterosuperior wall of the bladder and protruding into its lumen. The patient underwent complete excision of the bladder lesion for the presumed diagnosis of rhabdomyosarcoma. Histopathological examination showed a fluid-filled space lined by stratified squamous epithelium with areas of intestinal metaplasia, revealing an unexpected diagnosis of a urachal cyst. The patient was discharged with complete resolution of symptoms.ConclusionsIntravesical urachal cysts are a rare type of congenital urachal anomaly that may simulate a bladder malignancy, particularly if associated with infection. This case emphasizes the importance of considering urachal cysts in the differential diagnosis of bladder masses, especially in children, and specifically when the lesion is midline in the anterosuperior wall of the bladder.

Ectopic expression of HNF4α in Het1A cells induces an invasive phenotype

Barrett's oesophagus (BO) is a pathological condition in which the squamous epithelium of the distal oesophagus is replaced by an intestinal-like columnar epithelium originating from the gastric cardia. Several somatic mutations contribute to the intestinal-like metaplasia. Once these have occurred in a single cell, it will be unable to expand further unless the altered cell can colonise the surrounding squamous epithelium of the oesophagus. The mechanisms by which this happens are still unknown. Here we have established an in vitro system for examining the competitive behaviour of two epithelia. We find that when an oesophageal epithelium model (Het1A cells) is confronted by an intestinal epithelium model (Caco-2 cells), the intestinal cells expand into the oesophageal domain. In this case the boundary involves overgrowth by the Caco-2 cells and the formation of isolated colonies. Two key transcription factors, normally involved in intestinal development, HNF4α and CDX2, are both expressed in BO. We examined the competitive ability of Het1A cells stably expressing HNF4α or CDX2 and placed in confrontation with unmodified Het1A cells. The key result is that stable expression of HNF4α, but not CDX2, increased the ability of the cells to migrate and push into the unmodified Het1A domain. In this situation the boundary between the cell types is a sharp one, as is normally seen in BO. The experiments were conducted using a variety of extracellular substrates, which all tended to increase the cell migration compared to uncoated plastic. These data provide evidence that HNF4α expression could have a potential role in the competitive spread of BO into the oesophagus as HNF4α increases the ability of cells to invade into the adjacent stratified squamous epithelium, thus enabling a single mutant cell eventually to generate a macroscopic patch of metaplasia.

Effectiveness of Autologous Platelet-Rich Plasma and Stromal Vascular Fraction in Autologous Skin Grafting

Introduction: Despite the medical advances, burns remain a serious challenge and require new and promising treatment options, such as biomedical technologies with a high potential for burn wound treatment. However, high cost and complexity of biotechnologies limit their routine use, but autologous tissues, such as stromal vascular fraction (SVF) and autologous platelet-rich plasma (PRP), overcome these shortcomings. Objective: To demonstrate a successful case of using a combination of adipose-derived SVF and autologous PRP during autologous skin grafting in a severely burned patient. Material and methods: We present a successful case of 84-year-old Patient B. treated at Saint Petersburg I. I. Dzhanelidze Research Institute of Emergency Medicine in September-October 2022. He was diagnosed with a 11% (6%) / II-III degree flame burn of the head, neck, trunk, and upper extremities and first-degree inhalation injury. At the first stage, the general condition of the patient was stabilized, and he was prepared for surgery. At the second stage, on day 25 of treatment we performed skin grafting using split-thickness autografts with rare perforations and application of SVF and autologous PRP on a burn wound. We evaluated the treatment effectiveness using planimetry, cytology, and histology. Results: We observed complete engraftment of the autograft with no lysis or rejection during the first dressing change on day 3 after surgery and complete skin restoration on day 11. Cytologic findings over time showed an active decrease in inflammatory cells and an increase in regenerative cells, indicating successful wound healing. Histology demonstrated formation of normal stratified squamous epithelium with areas of hyperkeratosis and young granulation tissue in the superficial layers of the dermis on day 6. Conclusions: Our case demonstrated that the combination of SVF and autologous PRP facilitates split-thickness skin autograft engraftment.

Idiopathic Palatal Fistula of the Left Soft Palate.

Palatal fistulas, often congenital or trauma-induced, are occasionally encountered in the field of plastic surgery. We report a case of a non-medial 3mm soft palate fistula in a 43-year-old woman, with no apparent trigger or history of local trauma or infection. The fistula, extending 2cm toward the lateral pharyngeal wall, was surgically removed under general anesthesia as it was impacting the patient's quality of life. The lumen was stained, and the fistula was removed in one mass. The excised tissue was covered with stratified squamous epithelium and was surrounded by adherent tonsil tissue. No recurrence was observed postoperatively. Despite an initial suspicion of a congenital cause, the fistula's lateral extension and histology suggested a possible origin from the second pharyngeal pouch. To date, there are no reports of fistulas opening on the soft palate. Therefore, this presents an exceptionally rare instance of a soft palate fistula.

Artificial intelligence-based cancer progression prediction of oral premalignant lesions via self-supervised deep learning on histopathology.

90 Background: Premalignant lesions within the oral cavity demonstrate varied degrees of dysplasia. Oral stratified squamous epithelium is sensitive to carcinogenic insults and lesions progress to cancer at variable rates. The current diagnostic standard involves visual and tactile inspection followed by a biopsy. However, thus far, there is clinical ambiguity about which lesions may progress to carcinoma and there are insufficient prognostic tools available to guide clinical decision-making for follow-up. Deep learning is a form of artificial intelligence which can be applied to images. Self-supervised learning (SSL) and attention-based multiple instance learning (aMIL), are deep learning extensions which eliminate the need for pathologist annotations of histology and are more generalizable as the model learns general representations of unlabeled data, compared to traditional tile-based methods. We developed a novel artificial intelligence pipeline to predict progression to oral carcinoma using histological images from oral premalignant lesions. Methods: Digital histopathology images and clinical data cohorts were obtained from the US National Cancer Institute (n=561) and the University of Iowa (n=193) for training, and from the University of Chicago (n=214) for external validation. Patients were defined as progressing if initially non-malignant lesions had documented progression to carcinoma within 12 months of follow-up. Model training and evaluation was done in Python using our publicly available open-source Slideflow platform. We developed a deep learning pipeline utilizing SimCLR as an SSL method for feature extraction paired with an aMIL head for classification. The SimCLR feature generator was trained on only the training cohort, then used to generate features for both training and validation data. The aMIL model was trained on SimCLR-generated features. Trained model performance was evaluated on the external University of Chicago cohort and measured via areas under the receiver operating characteristic curve and precision recall curve (AUROC and AUPRC, respectively). During training and validation, model reliability was interpreted using Class Activation Mapping (Grad-CAM) and generative adversarial network (GAN) methods. Results: On training data, the model achieved average 3-fold cross validation AUROC of 0.86 with AUPRC of 0.83. In the external validation data from UC, the model achieved an AUROC of 0.80 with an AUPRC of 0.79. Deployed as a “rule-in” test for early progression prediction, the model achieved a validation data set specificity of 91% with a sensitivity of 40%. Conclusions: We developed a deep learning model to automatically predict cancer progression from premalignant lesions histopathology using a multi-institutional cohort, with promising external validation performance.

Molecular docking study of hyaluronic acid against interleukin-6 (7DC8 protein) in COVID-19 patients with periodontitis

Coronavirus disease 2019 (COVID-19) is a new disease caused by a coronavirus, namely SARS-CoV-2. This virus was entered inside the host by angiotensin-converting enzyme receptors (ACE2). Recent evidence suggests that sulcus fluid in the periodontal pockets of patients with periodontitis may be a source of SARS-CoV-2 and a potential reservoir for increasing oral viral load in patients with confirmed COVID-19. ACE-2 is expressed in stratified squamous epithelium mainly on the dorsal tongue and gingiva. The gingival sulcular epithelium is the entry point for SARS-CoV-2 into the periodontal pocket epithelium through the gingival crevicular fluid (GCF). Hyaluronic acid (HA) is a high molecule of heavy polysaccharide (glycosaminoglycan) which has several functions, such as anti-inflammatory and accelerated wound healing. It could decrease the levels of several cytokines. This study aims to analyze the interaction of HA against the IL-6 coronavirus receptor in periodontitis through a molecular docking study using MOE 2015.10 software with IL-6 receptor (7DC8) as the protein model to predict the binding of HA with 10 poses. The 7DC8 protein was prepared by adding charge and the validation method was performed with RMSD <2Å which indicates this method is valid. The results of this study showed that there are interaction between HA and the IL-6 receptor via amino acid residue interaction at the Leucine 98 (bond energy -0.7 kcal/mol), Serine 52 (bond energy -1.7 kcal/mol), Glycine 53 (bond energy -1.5 kcal/mol), and Glycine 299 (bond energy -1.6 kcal/mol). HA has an interaction with coronavirus at the IL-6 receptor of periodontitis based on molecular docking study and can potentially be used as a therapeutic option in COVID-19 with periodontitis. In conclusion, hyaluronic acid has the potential as an anti-inflammatory drug of choice in COVID-19 patients with periodontitis.

Morphological and histological study of the third eyelid in hedgehogs.

The third eyelid in animals plays an important role in maintaining eye health. Like other organs of the body, the third eyelid can be afflicted with minor or deep injuries, inflammations or even tumours in different species. The current study investigates the morphological and histological characteristics of the third eyelid in hedgehogs. Eight healthy adult hedgehogs (male and female) weighing 500-700g were included in this study. Deceased animals were used for this study. Few incisions were applied around the eye and eye socket. The eye was removed, and the samples were fixated in 10% formalin solution to prepare for the histological study. To evaluate the morphological characteristics, the third eyelid was placed in 2% and 4% formalin solutions. The histological study revealed that the third eyelid cartilage is an elastic cartilage and includes chondroblasts and chondrocytes. The cells of this cartilage were either distributed individually or in isogenic groups. The bulbar and palpebral surfaces of the eyelids were devoid of any glands and were covered with a non-keratinized stratified squamous epithelium. The anatomical examination also showed that the third eyelid had an oval-shaped cartilage. Comparing the results of this study with reports on other rodents showed that the morphological and histological structure of the cartilage in the hedgehog's third eyelid is mostly like the structure of this tissue in Indian mongoose (Herpestes javanicus).

Anatomy of the female reproductive tract organs of the brown anole (Anolis sagrei).

Female reproduction in squamate reptiles (lizards and snakes) is highly diverse and mode of reproduction, clutch size, and reproductive tract morphology all vary widely across this group of ~11,000 species. Recently, CRISPR genome editing techniques that require manipulation of the female reproductive anatomy have been developed in this group, making a more complete understanding of this anatomy essential. We describe the adult female reproductive anatomy of the model reptile the brown anole (Anolis sagrei). We show that the brown anole female reproductive tract has three distinct anterior-to-posterior regions, the infundibulum, the glandular uterus, and the nonglandular uterus. The infundibulum has a highly ciliated epithelial lip, a region where the epithelium is inverted so that cilia are present on the inside and outside of the tube. The glandular uterus has epithelial ducts that are patent with a lumen as well as acinar structures with a lumen. The nonglandular uterus has a heterogeneous morphology from anterior to posterior, with a highly folded, ciliated epithelium transitioning to a stratified squamous epithelium. This transition is accompanied by a loss of keratin-8 expression and together, these changes are similar to the morphological and gene expression changes that occur in the mammalian cervix. We recommend that description of the nonglandular uterus include the regional sub-specification of a "cervix" and "vagina" as this terminology change more accurately describes the morphology. Our data extend histological studies of reproductive organ morphology in reptiles and expand our understanding of the variation in reproductive system anatomy across squamates and vertebrates.

A case series of epidermoid cysts of external ear in paediatric age group at our tertiary institution

Epidermoid cyst is a benign, small, subcutaneous, extremely rare, developmental cyst of head and neck region. Case series analysis with duration of one year from June 2021 till June 2022 with study population comprised of five- patients in the paediatric age group that is age ≤12 years with epidermoid cyst over the external ear. All of our cases were benign and asymptomatic in nature and without any recurrence in follow up while the case one and five were having large size with the gross deformity of external ear which is uncommon. The histopathological examination in all cases shown fibro-collagenous cyst wall lined by keratinizing stratified squamous epithelium with a prominent granular cell layer with abundant keratin flakes. All cases shown successful surgical outcome which was confirmed by lack of postsurgical alterations and no recurrence of the lesion during follow up of next 6 months.

Congenital heterotopic gastrointestinal duplication cyst of the face: a rare case report

Gastrointestinal duplication (GDC) cysts have various synonyms; choristoma, enterocystoma, and duplication cyst. They are infrequent congenital benign lesions diagnosed mainly in children in the first decade of life, comprising approximately less than 5% of the pediatric population with a predilection for the male sex. It is exceedingly rare in the oral cavity but it is possible, particularly on the tongue, floor of the mouth, and pharynx. From 1895 until 1994, 30 cases of this lesion in the oral cavity were reported. Nowadays, none of the authors reported a GDC in the facial region. We report an exceptional case of heterotopic gastrointestinal duplication cysts (HGDC) in the facial region of a 13 -years -old male teenager who was referred to our medical department for an evaluation of a painless progressive facial asymmetry. In the first instance, the ultrasound facial soft tissue was made with a 6.5 MHz convex transducer, reporting a big anechoic image with regular borders to a 60 x 26 x 56 mm diameter with a 46cc approximate volume. Following this, a non-contrast magnetic resonance image was executed with an open Philips PanoramaⓇ machine performed at 3T, reporting a hyperintense image in T2-weighted (repetition time msec/echo time msec: 5,500/112) sagittal sequence and FLAIR-weighted (5,714/80) axial sequence; and an isointense image in T1-weighted (24/80) coronal sequence to 54 x 30 x 51 mm diameter compatible with space occupant lesion with interior walls. A complete tumor resection was achieved under balanced general anesthesia, and the specimen was sent for histological examination. Microscopic examination showed a cystic cavity lined mostly by mucous secretory gastrointestinal epithelium and other areas by stratified squamous epithelium. The cystic wall was composed of fibrous connective tissue and contains abundant gastric cells. Its deepest portion exhibits a smooth muscle layer. In summary, HGDC is an unusual congenital head and neck lesion, but it should be considered in the differential diagnosis of neonates and children. The diagnosis of gastrointestinal tract duplications may be suggested by imaging studies; however, the correct diagnosis is defined by histopathologic analysis. Due to the risk of destruction potential and malignant transformation, HGDC should be treated surgically by complete excision.