Histomorphometrical study of the tongue epithelium of the peregrine falcon (Falco peregrinus)

The aim of this study is to examine the dorsal lingual epithelium of the peregrine falcon (Falco peregrinus) of the family Falconidae. The tongue in its dorsal, lateral and ventral surfaces is covered with a non-keratinized multilayered stratified squamous epithelium. Lamina propria is present beneath the epithelial layers. Morphometrically, thickness of the apex tongue epithelium is more than that in the tongue body. Thickness of the ventral surface of the tongue is less than that in the dorsal one. Thickness of the lateral surface of the tongue was thicker than that in the ventral one and tongue body. Large and small conical papillae appeared on the posterior dorsal surface of the lingual body. There are lingual glands in certain areas of tongue body with numerous openings through the dorsal surface.

Morphological characteristics of changes in the squamous epithelium of the upper part of the digestive tract in model organisms in the settings of provoked carcinogenesis

Relevance: Noticeable spreading of malignant neoplasms of upper section of digestive system and the worsening of these patients’ quality of life in case of late diagnostics stimulate the development of protocols for early detection of precancerous changes. The purpose of the study was to investigate the morphological characteristics of changes in the squamous epithelium of the upper part of the digestive tube in model organisms under provoked carcinogenesis when exposed to substances with proven carcinogenic activity. Methods: 40 female nonlinear white rats obtained from the Orekhovo-Zuevsky urban settlement veterinary station were used as model organisms. The rats were divided into 4 equal groups. The first control group was not exposed to any specific influences. In groups 2-4, the rats underwent sedation and mechanical scarification microtraumatization of the oral mucosa. Then, they were applied twice a week by 0.9% NaCl solution (control group 2), 1% aqueous solution of dimethyl sulfoxide (DMSO, Akrikhin, Russia) (control group 3), or 1% aqueous solution of DMSO containing 0.1 mg/ml 4-nitroquinoline-N-oxide (4- NQO, Acros Organics, USA) (experimental group 4). Results: The cytological picture associated with chronic trauma to the mucous membrane of the upper digestive tract was characterized by nonspecific reactions: inflammation, hyper- and parakeratosis, and atrophic changes. There were no statistically significant differences in the frequency of such changes between the experimental and control groups. Specific changes in squamous epithelium towards a precancerous state in the experimental group with chronic exposure to a substance with carcinogenic activity occurred significantly more often than in the control groups (p <0.05), as proven by the results of comparative histological verification. Conclusion: Cytological study can be offered for clinical study as a screening tool for precancerous oropharynx and upper esophagus conditions

The Squamous Vaginal Papillomatosis in Prepubertal Female Twins: A Case Report

This is the first case describing vaginal papillomatosis with a fibroepithelial polyp of the vulva in a prepubertal girl and vaginal papillomatosis in her twin sister. Parents contacted pediatric urologist regarding their eight-year-old daughter (twin A), who had a growth next to the external urethral meatus. The girl was referred to a pediatric surgeon. The exophytic 3 cm long structure with necrosis on top was found. After obtaining informed consent from girl parents, pediatric surgeon removed the exophytic structure and perform cystoscopy and vaginoscopy for possible changes in the bladder and vagina. Cystoscopy findings were normal. On vaginoscopy, numerous macroscopic papillomatous structures were identified on the cervix and vaginal walls. Vaginal biopsies were performed on the areas affected by papillomatosis. Histopathologic examination showed a fibroepithelial polyp with a central fibrovascular core covered by squamous epithelium and vaginal squamous papillomatosis. The decision was made to perform vaginoscopy on her twin sister (twin B), too. On vaginoscopy, solitary small vaginal papillomas were also found. In this case manifestation of vaginal papillomatosis in twins might have been influenced by inheritance and the same bacterial and viral environment.

Squamous Differentiation in the Thyroid: Metaplasia, Neoplasia, or Bystander?

Background. Squamous differentiation within the thyroid is seen in a variety of settings. Squamous epithelium is non-native to the thyroid, and its debated origins span reactive metaplasia and developmental/embryologic remnants. Despite a lack of clarity as to its evolution, squamous epithelium may be associated with both neoplastic and non-neoplastic processes. Methods. Thyroid pathology reports spanning a 30-year period were reviewed for terms indicating squamous features. Associated diagnostic and clinical information was collated. Results. Four hundred and twenty seven of 17,452 (2.4%) thyroid surgical pathology cases during this period utilized terminology indicating squamous differentiation including 243 malignant (58%) and 178 benign (42%) diagnoses. There were 111 (26%) primary thyroid malignancies with squamous differentiation, 116 (28%) malignancies of non-thyroid origin including local extension from nearby cancers, and 16 (4%) malignancies of uncertain primary. Most benign lesions were non-neoplastic (84%). The minor subset representing benign neoplasia was interpreted as secondary reactive changes. Conclusion. While squamous differentiation is seen routinely in the thyroid, it is most commonly reported in malignancy. For primary thyroid malignancies reported to demonstrate a squamous component, biologically aggressive tumors were overrepresented. Available evidence suggests that multiple pathways may contribute to the presence of squamous epithelium in the thyroid including metaplasia of mature follicular cells, development from established embryonic remnants, or inception in putative, incompletely characterized stem-like cells. Our retrospective review presents an institutional landscape from which further investigation into the frequency and unique histologic and molecular context of intrathyroidal squamous differentiation as a driver or terminal event in thyroid pathophysiology.

Generation of a lung squamous cell carcinoma three-dimensional culture model with keratinizing structures

Tumor nests in lung squamous cell carcinoma (LUSC) have a hierarchical structure resembling squamous epithelium. The nests consist of basal-like cells on the periphery and layers of keratinocyte-like cells that differentiate towards the center of the nest, forming keratin pearls. Reproducing this spatial heterogeneity in in vitro models would be useful for understanding the biology of LUSC. Here, we established a three-dimensional (3D) culture model with a squamous epithelial structure using LUSC cell lines PLR327F-LD41 and MCC001F, established in-house. When PLR327F-LD41 cells were cultured in a mixture of Matrigel and collagen I, they generated 3D colonies (designated cancer organoids, or COs) with involucrin (IVL)-positive keratinizing cells in the center (IVLinner COs). COs with uniform size were generated by seeding PLR327F-LD41 cells in a form of small cell aggregates. Since Notch signaling induces the differentiation of squamous epithelium, we confirmed the effect of γ-secretase inhibitor in inhibiting Notch signaling in IVLinner COs. Surprisingly, γ-secretase inhibitor did not block induction of IVL-positive cells; however, cells residing between the CK5-positive basal-like layer and IVL-positive layer decreased significantly. Thus, our 3D culture model with uniform size and structure promises to be a useful tool for elucidating the biology of LUSC and for screening drug-candidates.

Identification and Characterization of Stem Cells in Mammalian Esophageal Stratified Squamous Epithelia

Somatic stem cells are essential for maintenance of cell proliferation-differentiation homeostasis in organs. Despite the importance, how the esophageal epithelium that executes its self-renewal and maintenance remains elusive. In this study, using 5-bromo-2'-deoxyuridine (BrdU) label-chase in rat and rat esophageal keratinocyte cell line-derived organoids together with genome-wide DNA methylation profiling and single-cell RNA sequencing (scRNA-seq), we identify slow cycling/quiescent stem cell population that contain high levels of hemidesmosome (HD)’s and low levels of Wnt signaling localized spatially and randomly at the basal layer of the esophageal epithelium. Pseudo-time cell trajectory from scRNA-seq indicates that cell fates begin from quiescent basal cells (the stem cells) of the basal layer that produce proliferating and/or differentiating cells in the basal layer, which, in turn, progress into differentiating cells in the suprabasal layer, ultimately transforming into differentiated keratinocytes in the differentiated layer. Perturbations of HD component expressions and/or Wnt signaling reduce stem cell in the basal layer of esophageal keratinocyte organoids, resulting in alterations of organoid formation rate, size, morphogenesis and proliferation-differentiation homeostasis. Furthermore, we show that not only high levels of HDs and low levels of Wnt signaling but also an interplay between HD and Wnt signaling defined stem cells of the basal layer in the esophageal squamous epithelium. Hence, HDs and Wnt signaling are the critical determinants for defining stem cells of the basal layer required for proliferation-differentiation homeostasis and maintenance in the mammalian esophageal squamous epithelium.

Iatrogenic Cervical Epidermoid Cyst Following Tracheostomy

Epidermoid cysts are generally benign lesions surrounded by squamous epithelium with cystic contents. The lining of the cysts produce keratin, which resemble a cheese-like material. They typically occur in the skin and mucous membranes and are congenital in origin; iatrogenic epidermoid cysts are rare. Epidermoid cysts are usually painless and asymptomatic, and their diagnosis is based on histological examination. This paper aims to present the case report of a 23-year-old patient with an iatrogenic epidermoid cyst that occurred following tracheostomy. The importance of preoperative radiological imaging in the diagnosis of epidermoid cysts is also highlighted.

Polarimetry feature parameter deriving from Mueller matrix imaging and auto-diagnostic significance to distinguish HSIL and CSCC

High-grade squamous intraepithelial lesion (HSIL) is regarded as a serious precancerous state of cervix, and it is easy to progress into cervical invasive carcinoma which highlights the importance of earlier diagnosis and treatment of cervical lesions. Pathologists examine the biopsied cervical epithelial tissue through a microscope. The pathological examination will take a long time and sometimes results in high inter- and intra-observer variability in outcomes. Polarization imaging techniques have broad application prospects for biomedical diagnosis such as breast, liver, colon, thyroid and so on. In our team, we have derived polarimetry feature parameters (PFPs) to characterize microstructural features in histological sections of breast tissues, and the accuracy for PFPs ranges from 0.82 to 0.91. Therefore, the aim of this paper is to distinguish automatically microstructural features between HSIL and cervical squamous cell carcinoma (CSCC) by means of polarization imaging techniques, and try to provide quantitative reference index for pathological diagnosis which can alleviate the workload of pathologists. Polarization images of the H&E stained histological slices were obtained by Mueller matrix microscope. The typical pathological structure area was labeled by two experienced pathologists. Calculate the polarimetry basis parameter (PBP) statistics for this region. The PBP statistics (stat_PBPs) are screened by mutual information (MI) method. The training method is based on a linear discriminant analysis (LDA) classifier which finds the most simplified linear combination from these stat_PBPs and the accuracy remains constant to characterize the specific microstructural feature quantitatively in cervical squamous epithelium. We present results from 37 clinical patients with analysis regions of cervical squamous epithelium. The accuracy of PFP for recognizing HSIL and CSCC was 83.8% and 87.5%, respectively. This work demonstrates the ability of PFP to quantitatively characterize the cervical squamous epithelial lesions in the H&E pathological sections. Significance: Polarization detection technology provides an efficient method for digital pathological diagnosis and points out a new way for automatic screening of pathological sections.

Pathological Changes of the Rumen in Small Ruminants Associated with Indigestible Foreign Objects

The use of agriculture by-products is highly demanded for livestock nutrition. However, the employment of certain non-degradable materials could potentially induce concretions and lesions in ruminants’ forestomach. Thus, the aim of this study was to determine the morphological lesions showed in rumen containing indigestible foreign objects, named foreign bodies, in small ruminants. Twenty-two animals (12 goats and 10 ewes) presenting foreign bodies (2.750 ± 1.577 kg) were included in this study. Rumenotomies were performed to remove the foreign bodies, and rumen samples were taken for further morphological evaluations. Rumen samples from healthy small ruminants (n = 24) were also taken at slaughterhouses as controls. Morphologically, the rumen from affected animals showed a significant reduction of the ruminal papillae length (1.243 vs. 3.097), hyperplasia of the squamous epithelium, mononuclear infiltration in the subepithelial spaces and, less consistently, vacuolization of keratinocytes, presence of intraepithelial leukocytes and vascular changes of the lamina propria. It can be concluded that indigestible foreign bodies would cause ruminal lesions that would be able to trigger inflammatory and/or degenerative lesions. Our study demonstrates morphological lesions because of the presence of intraruminal foreign bodies, but further studies on the functional activity of the rumen in these cases are required. The avoidance of the presence of indigestible materials in agriculture exploitations is highly recommended in order to prevent the accumulation of indigestible foreign objects in small ruminants.

Complex Fibroadenoma with Pronounced Squamous Metaplasia: A Rare Case Report, Differential Diagnostic Considerations, and Associated Breast Cancer Risk

Squamous metaplasia of the breast is a rare and unusual finding. A number of benign and malignant differential entities exist when squamous cells are present in a breast lesion. Our patient was found to have pronounced squamous metaplasia and keratin cysts arising in a complex fibroadenoma. The rare nature of squamous metaplasia arising in such a lesion poses some diagnostic challenges, as squamous epithelium and squamous metaplasia in the breast may raise suspicion for malignancy. Herein we present a unique case and discussion of benign and malignant differential entities. We also retrospectively reviewed a series of complex fibroadenomas in our institution, including the demographic and histologic features, and more importantly the associated breast cancer risk.