Ozone exposure affects corneal epithelial fate by promoting mtDNA leakage and cGAS/STING activation

Ozone is a common air pollutant associated with various human diseases. The human ocular surface is frequently exposed to ozone in the troposphere, but the mechanisms by which ozone affects the ocular surface health remain unclear. This study aimed to establish a mouse model to investigate the effects of ozone exposure on the ocular surface and the corneal epithelium. The findings revealed that ozone exposure disrupted corneal epithelial homeostasis and differentiation, resulting in corneal squamous metaplasia. Further, ozone exposure induced oxidative damage and cytoplasmic leakage of mitochondrial DNA (mtDNA), thereby activating the cGAS/STING signaling pathway. The activation of the cGAS/STING signaling pathway triggered the activation of downstream NF-κB and TRAF6 signaling pathways, causing corneal inflammation, thereby promoting corneal inflammation and squamous metaplasia. Finally, C-176, a selective STING inhibitor, effectively prevented and treated corneal inflammation and squamous metaplasia caused by ozone exposure. This study revealed the role of mtDNA leakage-mediated cGAS/STING activation in corneal squamous epithelial metaplasia caused by ozone exposure. It also depicted the abnormal expression pattern of corneal epithelial keratin using three-dimensional images, providing new targets and strategies for preventing and treating corneal squamous metaplasia and other ocular surface diseases.

Squamous and glandular metaplasia related to a renal pelvis stone leading to secondary pyeloureteral junction syndrome

Keratinizing squamous metaplasia of the renal pelvis is a rare lesion of the upper urinary tract that can occur in the context of chronic aggression to the urothelium, potentially leading to a secondary pyeloureteral junction syndrome. We report the case of a 43-year-old patient discovered intraoperatively in relation to a renal pelvis stone causing a pyeloureteral junction syndrome. The extemporaneous histological examination ruled out a malignant process, and we performed a pyeloplasty according to KUSS-ANDERSON technique. This pathology should be recognized by the urologist for appropriate management. Treatment is conservative, with extended follow-up to detect recurrences or carcinomatous degenerations.

Recurrence of Rathke's Cleft Cyst Following Surgery and Histopathological Considerations for Recurrence: A Case Presentation

Recurrence of Rathke's cleft cysts (RCC) following surgery is not uncommon. We present a 33-year-old male patient with chronic headache and visual disturbances whose MRI showed mostly cystic, suprasellar mass with peripheral enhancement. Endoscopic extended transsphenoidal approach and tumor resection was performed and RCC was pathologically confirmed postoperatively. Early recurrence was first suspected at 3 months following surgery, and his serial MRIs showed a recurred mass without associated clinical symptoms. Upon further histopathological study, extensive squamous metaplasia and high Ki-67 were seen. Also, in this study, we discuss important factors associated with cyst recurrence following surgery.

DNA methylome analysis reveals potential alterations contributing to the progression of bronchial hyperplasia

BACKGROUND

Squamous cell lung cancer (SCLC) arises from bronchial changes: basal cell hyperplasia (BCH), squamous metaplasia (SM), and dysplasia. However, the premalignant process preceding SCLC is not inevitable; it can stop at any of the bronchial lesions. Previously, we hypothesized that combinations of premalignant lesions observed in the small bronchi of SCLC patients can reflect the different "scenarios" of the premalignant process: BCHi-the stoppage at the stage of hyperplasia and BCHSM-the progression of hyperplasia to metaplasia.

METHODS AND RESULTS

In this study, using whole-genome bisulfite sequencing we analyzed the DNA methylome of two forms of BCH: isolated BCH (BCHi) and BCH co-occurred with SM (BCHSM) in the small bronchi of SCLC patients. It was shown that BCHi harbored differentially methylated regions (DMRs) affecting genes associated with regulating phosphatase activity. In BCHSM, DMRs were found in genes involved in PI3K-Akt and AMPK signaling pathways. DMRs were also found to affect specific miRNA genes: miR-34a and miR-3648 in BCHi and miR-924 and miR-100 in BCHSM.

CONCLUSIONS

Thus, this study demonstrated the significant changes in DNA methylome between the isolated BCH and BCH combined with SM. The identified epigenetic alterations may underlie different "scenarios" of the premalignant process in the bronchial epithelium.

Pleomorphic Adenoma with Extensive Squamous and Adipocytic Metaplasia Mimicking as Low Grade Mucoepidermoid Carcinoma on FNAC

Pleomorphic adenoma (PA) is the most common salivary gland tumor, accounting for 54-76% of all salivary gland neoplasms. Extensive squamous metaplasia in PA can be mistaken for malignancy, including low grade mucoepidermoid carcinoma and squamous cell carcinoma. Here, we present an unusual case of PA with extensive squamous metaplasia and keratin cyst formations in a minor salivary gland, and discuss its microscopic features, including the immunohistochemical characteristics, and differential diagnosis of this uncommon presentation.

Effect of Silver Nitrate Cauterisation of Nasal Mucosa on Quality-of-Life and Histology in Patients with Intractable Chronic Rhinitis

Patients with chronic rhinitis causing intractable sneezing which is non-responsive to conventional medication require alternative therapies. The aim of the study was to ascertain the effect of topical 10% silver nitrate solution on the inferior turbinate mucosa as well as quality of life in such patients. Patients with severe chronic rhinitis who failed conventional therapy had application of 10% silver nitrate solution to inferior turbinate mucosa. The number of sneezes/day and mini Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score was noted before and 8 to 16 weeks after treatment. Pre- and post treatment turbinate biopsies were performed to assess histological changes. At baseline, 67 patients had a mean of 36.6 sneezes/day and mean mini RQLQ score of 4.0 ± 0.7. Pre-treatment biopsies showed epithelial denudation and hyalinization of basement membrane. Following 10% silver nitrate application, 64/67 (95.5%) patients showed significant reduction in number of sneezes both at 1 week (p < 0.001) and 8-16 weeks (mean = 5.5 ± 7.8; p < 0.001). Post- treatment mean global mini RQLQ score was also significantly reduced (mean = 1.3 ± 1.1; p < 0.001). A single application was sufficient in 70.1% patients. There were no complications. Squamous metaplasia (p = 0.005) and epithelial hyperplasia (p = 0.013) as well as epithelial and basement membrane restoration occurred following therapy. 10% silver nitrate solution application is an effective and safe office- based procedure which significantly reduces sneezing improves QoL with corresponding histological changes.

Tracheal squamous metaplasia in children with endotracheal intubation or tracheostomy

OBJECTIVES

In the present study, tracheal epithelial biopsy samples between intubated children, children with tracheostomy and a control group of non-intubated children are compared with respect to their degree of normal differentiation versus the presence of squamous metaplasia.

METHODS

Tracheal epithelial biopsies were obtained from intubated neonates undergoing tracheostomy, children with tracheostomy undergoing suprastomal granuloma excision and non-intubated control children undergoing laryngoscopy and bronchoscopy. Paraffin tissue blocks were sectioned at 5 μm thickness and subjected to both routine Hematoxylin and Eosin (H&E) staining and immunostained with the relevant antibodies for markers of epithelial differentiation including B-tubulin, CC10, Muc5ac, P63, keratin5 and keratin14.

RESULTS

Squamous metaplasia was seen in 3/3 infants, all intubated and in 3/3 children with tracheostomy tubes in place undergoing excision of suprastomal granuloma. No metaplasia was observed in control tracheal epithelial biopsies in 7/7 non-intubated children.

CONCLUSION

Our results demonstrate a clear association between intubation or tracheostomy and the presence of squamous metaplasia which is not otherwise encountered in control pediatric tracheal biopsies.

p63+Krt5+ basal cells are increased in the squamous metaplastic epithelium of patients with radiation-induced chronic Rhinosinusitis

Background

Squamous metaplasia (SM) is an irreversible form of airway epithelial remodeling. Hyperproliferation of basal cells was observed in squamous metaplastic epithelium of chronically inflamed airway. However, the association of such aberrant proliferation of basal cells with SM in the nasal epithelium after radiation damage remains unclear. The aim of this study was to investigate SM and accompanying levels of p63⁺Krt5⁺ (basal cell markers) cells in the nasal epithelium of patients with radiation-induced chronic rhinosinusitis (CRSr) and patients with chronic rhinosinusitis without nasal polyps (CRSsNP) compared to healthy controls.

Methods

We assessed the prevalence of SM and the expression of p63⁺, Krt5⁺, p63⁺Krt5⁺, and Ki67⁺ cells through immunofluorescence(IF) staining of the inferior turbinate (IT) tissues from patients with CRSr (n = 36), CRSsNP (n = 33) and controls (n = 28).

Results

The prevalence of SM and the number of p63⁺Krt5⁺ cells were both significantly increased in patients with CRSr compared to patients with CRSsNP and controls. The number of Ki67⁺ cells were both significantly increased in patients with CRSr and CRSsNP compared to controls, but the ratio of Ki67⁺ cells to p63⁺Krt5⁺ cells was significantly lower in patients with CRSr compared to patients with CRSsNP. In patients with CRSr, an increased number of p63⁺Krt5+ basal cells was observed in SM epithelium compared to non-SM epithelium.

Conclusion

SM is increased in the nasal epithelium of patients with CRSr, in which aberrant levels of p63⁺Krt5⁺ basal cells serves as an important pathologic feature in the squamous metaplastic epithelium.

The significance of mucinous metaplasia in Warthin tumor: a frequent occurrence and potential pitfall

Mucinous metaplasia in Warthin tumor (WT) is a recognized phenomenon. Nevertheless, its presence can create a diagnostic challenge in the distinction from the newly proposed variant of mucoepidermoid carcinoma (MEC), Warthin-like MEC. In this study, we evaluated the significance and diagnostic relevance of mucinous metaplasia in WTs. A total of 30 WTs diagnosed based on resection specimens formed the basis of this retrospective study. Mucicarmine staining was performed to identify mucinous metaplasia, and fluorescence in situ hybridization (FISH) analysis was used to detect MAML2 gene rearrangement. After review, one MAML2 rearranged case was reclassified as Warthin-like MEC as the classic bilayered epithelium in WT was not identified. The diagnosis of WT was confirmed in the remaining 29 cases. Mucinous metaplasia was encountered in 24 WTs (83%), with 14% (4/29) having an abundant amount. We found that mucinous metaplasia correlated with tumor size (p < 0.05). Age and sex distribution were similar in WT cases with or without mucinous metaplasia. In addition, neither the presence of squamous metaplasia nor the time interval between fine-needle aspiration and surgery was related to mucinous metaplasia (p > 0.05). The MAML2 FISH analyses performed in 18 WTs with variable amounts of mucinous metaplasia were negative for rearrangement. In conclusion, mucinous metaplasia is fairly common in WTs and shows a significant correlation with tumor size. Therefore, caution should be taken to avoid overinterpretation of WT with mucinous metaplasia as MEC in cases showing the classic bilayered oncocytic lining epithelium.

A Case Rarity: Papillary Thyroid Carcinoma with Squamous Metaplasia Complicated with Chronic Discharging Ulcers

We report a unique case of differentiated thyroid carcinoma (DTC) with squamous metaplasia complicated with chronic discharging ulcer. A 76-year-old gentleman was referred to us after defaulted treatment 1 year post-total thyroidectomy. He presented to us with long-standing chronic, non-healing, ulcerative and discharging wound at the anterior neck at previous total thyroidectomy scar. The primary tumour was histologically diagnosed as papillary malignant cells with extensive squamous metaplasia. Squamous metaplasia is a rare finding in thyroid carcinoma that carried a poorer prognostic factor.

Pure squamous cell carcinoma of the gallbladder locally invading the liver and abdominal cavity: A case report and review of the literature

BACKGROUND

Gallbladder squamous cell carcinoma (GBSCC) is a rare subtype of malignancy and accounts for only 2%-3% of gallbladder malignancies. Due to its rapid development, most patients with GBSCC initially present with an advanced stage of the disease and hence a poor prognosis. The clinicopathological and biological features of SCC remain to be fully elucidated, owing to its uncommon occurrence. The majority of currently available data only described individual case reports or series analyses of trivial cases.

CASE SUMMARY

A 64-year-old man was admitted for progressively poor abdominal distension and pain. Liver computed tomography (CT) showed infiltration of gallbladder carcinoma into the adjacent liver, and enlarged retroperitoneal lymph nodes. The patient underwent radical cholecystectomy. Part of the mass was grey and soft, and the neoplastic section showed a purulent-necrotic lesion. Hematoxylin and eosin staining revealed a moderately differentiated SCC. Immunohistochemical studies showed strong staining of the tumor for AE1/3 and CK5/6. Staining for CK19, CK7, and CAM5.2 was positive in the cytoplasm. Systemic chemotherapy was not administered because of the patient’s poor physical condition. After five months, CT and magnetic resonance cholangiopancreatography showed multiple metastases in the liver and abdominal cavity.

CONCLUSION

Squamous components of GBSCC may explain the complex biological behavior, and CD109 may be involved in the pathogenesis.

Premalignant lesions of squamous cell carcinoma of the lung: The molecular make-up and factors affecting their progression

Squamous cell carcinoma (SCC), one of the most common forms of lung cancer, shows accelerated progression and aggressive growth and usually is observed at advanced stages. SCC originates from morphological changes in the bronchial epithelium that occur during chronic inflammation: basal cell hyperplasia, squamous metaplasia, and dysplasia I-III. However, the process is not inevitable; it can be stopped at any stage, remain in the stable state indefinitely and either progress or regress. The reasons and mechanisms of different scenarios of the evolution of premalignant lesions in the respiratory epithelium are not fully understood. In this review, we summarized the literature data (including our own data) regarding genetic, epigenetic, transcriptomic and proteomic profiles of the premalignant lesions and highlighted factors (environmental causes, inflammation, and gene polymorphism) that may govern their progression or regression. In conclusion, we reviewed strategies for lung cancer prevention and proposed new models and research directions for studying premalignant lesions and developing new tools to predict the risk of their malignant transformation.

A first case of primary gastric verrucous carcinoma with isolated squamous epithelium in the stomach

Primary gastric squamous cell carcinoma (SCC) is a rare histological subtype of gastric cancer. Here, we report the first case of primary gastric verrucous carcinoma (VC), a well-differentiated variant of SCC. Gastroscopy revealed a papillary polypoid lesion at the posterior wall of the upper gastric body and isolated squamous epithelium at the greater curvature of the fornix in a 78-year-old woman. Endoscopic submucosal dissection was performed. Microscopically, the lesion comprised very well-differentiated squamous epithelium with minimal atypia and exhibited coarse papillary structure and bulbous epithelial downgrowth with submucosal invasion. Conventional SCC or adenocarcinoma components were not included, and the lesion was surrounded by the metaplastic intestinal mucosa. Human papillomavirus infection was not detected. Although the pathogenesis of primary gastric SCC remains controversial, here, the disease is suggested as having originated from squamous epithelium. Knowledge of primary gastric VC and difficulty in diagnosing it using surface biopsy is necessary.

Squamous Metaplasia in Pleomorphic Adenoma: A Diagnostic and Prognostic Enigma

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor. Histologically, squamous metaplasia has been reported in PA, but has rarely been documented as being extensive enough to cause significant misdiagnosis. Here, we present an unusual case of PA in a 50-year-old female patient presenting with swelling on the postero-lateral aspect of the palate for a week. Histopathologically, the tumor exhibited the features of conventional PA with extensive squamous metaplasia and giant keratotic lamellae in cyst-like areas. Such exuberant squamous metaplasia and keratin can be a diagnostic and prognostic pitfall and lead to overtreatment of the patient.

Paget's disease derived in situ from reserve cell hyperplasia, squamous metaplasia, and squamous cell carcinoma of the esophagogastric junction: a case report

Background

Extramammary Paget’s disease (EMPD) of the esophagus is a rare tumor, with most cases originating from invasive adenocarcinoma of the esophagus. Pure esophageal Paget’s disease, in which no underlying invasive carcinoma component is present, is extremely rare. In this report, we describe a case of EMPD of the esophagogastric junction with no evidence of invasive carcinoma.

Case presentation

An 81-year-old Japanese woman with a 2-week history of abdominal distension presented to our hospital for assessment. Endoscopic examination revealed a mild elevated granular lesion, with a slightly depressed irregular mucosa, in the distal esophagus, with EMPD confirmed by biopsy. Thoracoscopic esophagectomy with lymph node dissection was performed, with Paget cells observed on microscopic examination in the lower part of the esophageal epithelium. Only a few Paget cells stained positively for PAS/Alcian blue. Immunohistochemically, negative staining for CK5 and p63 were identified in the Paget cells, with positive staining for CK7. Furthermore, an intraepithelial squamous cell carcinoma, with squamous metaplasia and reserve cell hyperplasia, was observed in the gastric mucosa of the esophagogastric junction, adjacent to the Paget cells.

Conclusions

EMPD of the esophagus is a rare disease. We report a case of EMPD that was probably derived from a gastric squamous cell carcinoma, with squamous cell metaplasia and reserve cell hyperplasia, in the esophagogastric junction, which, to our knowledge, is the first report of this type of EMPD in the clinical literature.

Derivation of thyroid lymphoepithelial cysts from follicular cells

The pathogenesis of thyroid lymphoepithelial cysts is controversial, and two hypotheses have been proposed, namely derivation from branchial-derived remnants or from squamous metaplasia of the follicular cells. The aim of this study was to clarify the pathogenesis of thyroid lymphoepithelial cysts. We performed pathological and immunohistochemical examination of 21 thyroid lymphoepithelial cysts, 13 non-neoplastic squamous metaplasia samples without thyroid carcinoma, 13 solid cell nests, and 14 lateral cervical cysts. On ultrasound, half of thyroid lymphoepithelial cysts were interpreted as calcified nodules regardless of no calcification. Thyroid lymphoepithelial cysts and squamous metaplasia tended to be located in the central and lower portions of the thyroid, while solid cell nests were located in the upper and central portions (p < 0.05). In 95.2% of patients with thyroid lymphoepithelial cysts and all patients with squamous metaplasia, lesions were histologically associated with chronic thyroiditis forming lymph follicles. Hashimoto's disease was serologically confirmed in 18 patients with lymphoepithelial cysts (85.7%) and 10 patients with squamous metaplasia (76.9%). Immunohistochemically, lymphoepithelial cysts showed nuclear positivity for PAX8, thyroid transcription factor 1, and p63. One lateral cervical cyst (7.1%) showed positive staining for PAX8, while solid cell nests were PAX8-negative. In three (14.3%) cases of thyroid lymphoepithelial cysts, squamous cells located on the superficial layer were focally and weakly positive for CEA. We concluded that thyroid lymphoepithelial cysts originate from follicular cells and are unrelated to solid cell nests and lateral cervical cysts arising from branchial-derived remnants.

[Ichthyosis uteri (psoriasis uteri) : A very rare disorder]

In ichthyosis uteri, the entire endometrium is replaced by squamous, sometimes even keratotic epithelium. The etiology is discussed controversially and not fully understood. However, in most cases a chronic inflammatory stimulus is identified. An association with malignancy is possible. Therefore, adequate consecutive diagnostic procedures, as well as exact macro- and micromorphologic evaluation is mandatory. In this case report we describe this currently rare disorder and review the main literature on this topic.

Squamoid morules in the pseudoinvasive foci of colonic polyp morphologically mimic invasive carcinoma

Colorectal adenomas can show focal squamous differentiation or squamoid morules. We describe histologic findings of squamoid morules in the pseudoinvasive foci of colorectal polyps mimicking invasive carcinoma. Five colonic polyps with squamoid morules in the pseudoinvasive foci were collected. Histologic review and immunostains for cytokeratin 5/6, p63, synaptophysin, and chromogranin were performed on cases with squamoid morules. Forty-seven consecutive colorectal polyps with pseudoinvasion, none of which showed squamoid morules by histology review, and their clinicopathologic features were compared with the cases containing squamoid morules. Cases with squamoid morules more frequently occurred in younger patients (P=.047) and were located in right colon (P=.027) than those without squamoid morules. Diagnosis of the polyps included tubular/tubulovillous adenoma with low-grade (with squamoid morules, n=3; versus without squamoid morules, n=29) or high-grade dysplasia (n=2 versus n=15) and sessile serrated adenoma (none versus n=3). Squamoid morules formed nodules protruding into the lumen of glandular structures or partially replaced adenomatous glands without forming a discrete nodule. They also presented as solid nests showing a well-formed morular structure around the bottom of adenomatous glands or myxoinflammatory stroma. Importantly, squamoid morules often formed a pseudocribriform or solid nest sitting in the stroma of pseudoinvasive foci. All cases (n=4) showed cytokeratin 5/6 positivity and p63 negativity in squamoid morules. Three and 1 of 4 cases showed focal positivity for synaptophysin and chromogranin, respectively, in squamoid morules. Squamoid morules in colonic adenomatous polyps can mimic invasive carcinoma when present in the pseudoinvasive foci. Pathologists should be aware of their presence.

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma with squamous differentiation: a novel histological finding

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare neoplasm originating from the nasopharyngeal surface epithelium. Histopathologically, TL-LGNPPA is characterized by cuboidal/columnar tumor cells forming papillary fronds and thyroid transcription factor-1 (TTF-1) expression resembling papillary thyroid carcinoma. To date, the recorded histological features of TL-LGNPPA have been almost uniform, and the range of histological variations in this tumor type has not been sufficiently understood. Here, we report on a 68-year-old man with TL-LGNPPA. Microscopic examination of the resected tumor revealed findings typical of papillary adenocarcinoma of this type, and moreover, this case showed scattered squamous cell foci as a hitherto unreported finding. The squamous cells showed no obvious nuclear atypia or proliferating activity, and their presence was similar to the "squamous metaplasia" of papillary thyroid carcinoma. Immunohistochemically, p40 and TTF-1 coexpression was observed in the squamous cell nuclei, indicating their origin from the glandular tumor cells of TL-LGNPPA.

Influence of Deviated Nasal Septum on Nasal Epithelium: An Analysis

Nasal obstruction is one of the most common complaint that ENT surgeon faces in his day to day practice. Deviated nasal septum is the most common cause for the nasal obstruction. It causes altered airflow dynamics which leads to various histopathological changes in nasal mucosa.Histopathological changes like lymphocytic infiltration and squamous metaplasia were studied and comparison was done between convex and concave side. A prospective randomized study conducted on 42 patients of deviated nasal septum from January 2015 to December 2015 selected from inpatient department of Otorhinolaryngology, KLES Dr. Prabhakar Kore Hospital and Medical Research Center, Belagavi. This study determined significantly higher rate of squamous metaplasia and lymphocytic infiltration in septal mucosa on concave side when compared with convex side. Furthermore, there was increased lymphocytic infiltration and squamous metaplasia in lateral wall mucosa on concave side as compared to convex side but the difference was not statistically different. Deviated nasal septum predisposes the nasal epithelium to chronic inflammation and squamous metaplasia as a result of altered airflow. Due to changes in pathophysiology the patient is more susceptible to chronic rhinitis/rhinosinusitis.

The analysis of human conjunctival epithelium proteome in ocular surface diseases using impression cytology and 2D-DIGE

Conjunctival impression cytology samples from patients with meibomian gland dysfunction (MGD), dry eye (DE), and healthy subjects (CT) were collected for determination of the degree of squamous metaplasia (SM) by PAS-hematoxylin staining and for comparative proteomic analyses by 2D-DIGE. The protein spots with discriminant expression were identified by MALDI-TOF/TOF mass spectrometry. Three independent statistical studies were conducted: i). Analysis of differential protein expression between study groups: We observed increased expression of proteins S100A4, S100A8, retinal dehydrogenase-1, peroxiredoxin-1, annexin-A1, annexin-A2, α-enolase, and glutathione S-transferase-P in DE, whereas the highest expression of peroxiredoxin-6, actin cytoplasmic-1, peroxiredoxin-2, and heat shock protein HSP-90-α was observed in MGD; ii). Correlation between changes in the proteome profile and the grade of SM: The expression of 5 different cytokeratins (KRT1, KRT4, KRT8, KRT10, and KRT13) correlated with the degree of SM; iii). Proteome profile differences between pathological and CT groups: An overall proteome analysis revealed upregulation of 9 proteins in the pathological groups (Annexin-A1, α-enolase, Annexin-A2, S100A8, cytokeratin-1, Peroxiredoxin-2 and Leukocyte elastase inhibitor) and downregulation of 2 proteins (Galectin-3 and Lipocalin-1). In conclusion, a sensitive proteomic approach to study conjunctival tissue collected from minimally invasive impression cytology was implemented. Differential proteomics analyses showed that in comparison with the MGD, the DE patients presented higher overexpression of proteins related to antimicrobial defense, tissue-damage response, and regulation of body fluid secretions. Changes in MGD proteome were associated with oxidative stress and anti-apoptotic processes. We found a correlation between the grade of SM and expression of proteins associated with cytoskeleton and keratinization. The studied pathological groups shared elements related to the defense and inflammatory responses. Dot blot assays of proteins ANXA1, S100A8, and S100A4 validated the proteomic results obtained from 2D-DIGE experiments and confirmed the correlation between the expression of these proteins and the clinical parameters.

Decreased RARβ expression induces abundant inflammation and cervical precancerous lesions

It is well known that vitamin A and its receptors protect against cancer development and that Retinoid Acid Receptor β (RARβ) is epigenetically silenced during tumoral progression. Cervical Cancer (CC) has been causally linked to high risk human papillomavirus (HR-HPV) infection. However, host factors are important in determining the outcome of persistent HR-HPV infection as most cervical precancerous lesions containing HR-HPVs do not progress to invasive carcinomas. Increasing evidence suggests that low diet in vitamin A and their receptors participate in the development of CC. The aim of this study has been to investigate the effects of abated RARβ expression in the development of cervical premalignant lesions in 4 month-old conditional mice (RARβ(L-/L-)). Results demonstrated the development of spontaneous squamous metaplasia, inflammatory infiltrate, enhanced mitotic activity, loss of cell differentiation, as well as decreased apoptosis and p16(INK4a) protein levels in RARβ(L-/L-) mice cervix. All these changes are hallmarks of moderate dysplasia. Importantly, our results suggest that the low expression of RARβ, may induce the down regulation of p16(INK4a), chronic inflammation and decreased apoptosis and may be involved in vulnerability to HR-HPV and early stage cervical carcinogenesis.

Clusterin in the eye: An old dog with new tricks at the ocular surface

The multifunctional protein clusterin (CLU) was first described in 1983 as a secreted glycoprotein present in ram rete testis fluid that enhanced aggregation ('clustering') of a variety of cells in vitro. It was also independently discovered in a number of other systems. By the early 1990s, CLU was known under many names and its expression had been demonstrated throughout the body, including in the eye. Its homeostatic activities in proteostasis, cytoprotection, and anti-inflammation have been well documented, however its roles in health and disease are still not well understood. CLU is prominent at fluid-tissue interfaces, and in 1996 it was demonstrated to be the most highly expressed transcript in the human cornea, the protein product being localized to the apical layers of the mucosal epithelia of the cornea and conjunctiva. CLU protein is also present in human tears. Using a preclinical mouse model for desiccating stress that mimics human dry eye disease, the authors recently demonstrated that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration in the tears. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to LGALS3 (galectin-3), a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. CLU depletion from the ocular surface epithelia is seen in a variety of inflammatory conditions in humans and mice that lead to squamous metaplasia and a keratinized epithelium. This suggests that CLU might have a specific role in maintaining mucosal epithelial differentiation, an idea that can now be tested using the mouse model for desiccating stress. Most excitingly, the new findings suggest that CLU could serve as a novel biotherapeutic for dry eye disease.

High-grade Neuroendocrine Carcinoma With Focal Squamous Metaplasia of Renal Pelvis Associated With Renal Calculus: Study of a Case

Mixed neuroendocrine and non-neuroendocrine type of tumor in renal pelvis is rare and presents a high-grade malignancy. We present a case report that a 57-year-old man had no history of small cell cancer but presented a high-grade neuroendocrine carcinoma with focal squamous metaplasia and multiple stones simultaneously in the right renal pelvis. The patient underwent nephroureterocystectomy 9 months before this presentation, with evidence of multiple metastatic tumors in various parts of the body. The case of mixed neuroendocrine tumor with stones in the renal pelvis carries a poor prognosis and poses a therapeutic challenge to urologists.

Ameloblastic carcinoma: Report of a rare case

Ameloblastic carcinoma is a rare odontogenic tumor exhibiting histological evidence of malignancy in the primary or recurrent tumor. It is characterized by rapid, painful expansion of the jaw, unlike conventional ameloblastomas. The tumor most frequently involves the mandible. The expanding lesion causes perforation of the buccal and lingual plates of the jaw and invades the surrounding soft tissue. Rapidly growing large tumor mass may cause tooth mobility. A mandibular tumor involving the mental nerve leads to paresthesia of the nerve. A maxillary tumor can produce a fistula in the palate and paresthesia of the infraorbital nerve. Most ameloblastic carcinomas are presumed to have arisen de novo with a few cases of malignant transformation of ameloblastomas. Although rare, these lesions have been known to metastasize, mostly to the regional lymph nodes or lungs. A case of ameloblastic carcinoma in a 60-year-old man is reported here and its clinical, radiological and histological features are discussed.

A case of squamous metaplasia of the stomach

Intestinal metaplasia of the stomach is a common metaplastic lesion associated with chronic gastritis and mucosal atrophy. However, squamous metaplasia is a comparatively rare condition. On endoscopy, squamous metaplasia is usually observed as a whitish mucosal lesion in the lesser curvature of the cardiac region of the stomach. When Lugol's iodine solution is applied, the lesion stains brown in the same way as normal esophageal mucosa. We report a case of 79-year-old man with a whitish flat lesion in the lesser curvature of the cardiac region on surveillance endoscopy after endoscopic treatment of gastric adenoma. The endoscopic biopsy showed stratified squamous epithelial mucosa.

Squamous cell carcinogenesis and squamous cell carcinoma of the urinary bladder: a contemporary review with focus on nonbilharzial squamous cell carcinoma

Bladder squamous cell carcinoma, squamous metaplasia, and transitional cell carcinoma with squamous differentiation are infrequent findings in Western countries. A common risk factor for their development consists of chronic bladder irritation and inflammation. The prognostic and clinical relevance and natural history of squamous cell lesions has been under investigation, revealing individual premalignant characteristics. Recent developments in molecular characterization of squamous alterations of the urinary tract indicate pathogenetic similarities and interrelations and might lead to more precise tumor classification and risk stratification in the future. Nevertheless, current clinical management of patients with premalignant and malignant bladder squamous cell lesions remains challenging, as high evidence level studies are not available and prognosis of invasive squamous carcinoma is poor. Our review summarizes the available data on clinical presentation, treatment, and outcome of bladder squamous cell carcinoma, metaplastic lesions, and transitional cell carcinoma with squamous differentiation and discusses implementable current advances in the understanding of bladder cancer tumorigenesis.

Study of histopathological changes in atrophic rhinitis

A punch biopsy from the inferior turbinate was taken in 71 consecutive cases of atrophic rhinitis and studied for histopahtological changes. Squamous metaplasia was seen in 85 percent of cases. Tunica propria showed granulation tissue (41 percent) and chronic inflammatory cellular infiltrate (32 percent). Mucosal glands were decreased in 42 percent of cases and absent in 28 percent. Areas of dilated vessels were observed in 35 percent and decreased vascularity in 59 percent of cases. These observations are similar to those reported by others. Total squamous metaplasia with keratinisation and hypertrophy was seen by us in one case. This has not been reported earlier.

Ocular Surface Changes in Primary Open Angle Glaucoma with Long Term Topical Anti Glaucoma Medication

BACKGROUND

Topical life long anti glaucoma medication forms the mainstay of treatment of primary open angle glaucoma. Their long term usage can cause changes in conjunctival epithelium.

METHODS

Hundred cases of primary open angle glaucoma were divided into four groups of 25 patients each. Each group was put on Timolol, Pilocarpine, Brimonidine and Latanoprost respectively. Ocular surface changes were monitored using Schirmer's test, tear film break up time (BUT) and conjunctival impression cytology.

RESULT

Altered Schirmer's test value was seen in 40% of patients and reduced tear film BUT values in 26%, at the end of one year. These changes were more in patients treated with timolol. Changes in conjunctival cytology such as decrease in goblet cell density, squamous metaplasia and presence of inflammatory cells were seen in significant number of patients at the end of one year treatment. There was direct relation of duration of treatment to various ocular surface changes.

CONCLUSION

Ocular surface changes are seen in significant number of patients of primary open angle glaucoma at the end of one year follow up with topical anti glaucoma therapy. Conjunctival impression cytology is a non invasive technique to monitor these changes.

A squamous metaplasia in a gastric ulcer scar of the antrum

An 81-year-old man presented with epigastric pain and weight loss for one month. He had a past history of pulmonary tuberculosis, 10 years ago. We performed a gastroscopy, which showed a linear depressed whitish gastric ulcer scar (0.8 cm in length) in the posterior wall of the prepyloric antrum. The result of biopsy was reported as squamous epithelium. Immunohistochemical staining using an antibody to high molecular weight cytokeratin (HMC) revealed positive staining in the squamous epithelium. Two years later, the lesion was followed up. The lesion remained at same site endoscopically, but no squamous epithelium could be seen microscopically.