Histopathological and immunohistochemical analysis of a suspected extraskeletal osteosarcoma in a rabbit (Oryctolagus cuniculus).

An 8-year-old male rabbit (Oryctolagus cuniculus) presented with a subcutaneous mass in the proximal region of the fourth and accessory digit measuring 5.5 x 3.5 x 5.2cm. The mass was non-alopecic and exhibited irregular surface, ulceration and necrosis with predominantly pale and light brown coloring. Radiography revealed no involvement of bone and adjacent periosteum. The mass was marginally resected and the electrochemotherapy (ECT) was performed on the surgical bed. Histopathology and immunohistochemical analysis revealed positive reactions for Vimentin, Runx-2 and ki-67, leading to a diagnosis of extraskeletal osteosarcoma (ESOS). This report described a case of ESOS in a rabbit, thereby delineating its clinical presentation, anatomopathological characteristics, diagnostic modalities and recommended therapeutic interventions.

Um coelho macho de 8 anos (Oryctolagus cuniculus) apresentava uma massa subcutânea na região proximal do quarto e acessório dígitos medindo 5,5 x 3,5 x 5,2 cm. A massa não era alopécica e exibia superfície irregular, ulceração e necrose com coloração predominantemente pálida e marrom clara. A radiografia não revelou envolvimento de tecido ósseo ou periósteo adjacente. A massa foi submetida à excisão marginal e foi realizada eletroquimioterapia do leito cirúrgico. Histopatologia e análise imuno-histoquímica revelaram reações positivas para vimentina, Runx-2 e ki-67, levando ao diagnóstico de osteossarcoma extraesquelético. Este relato descreve um caso de osteossarcoma extraesquelético em um coelho, delineando sua apresentação clínica, características anatomopatológicas, modalidades diagnósticas e intervenções terapêuticas recomendadas.

Decreased Nuclear Immunoexpression of ING3 is a Frequent Event in Lip Carcinogenesis.

PURPOSE: Evaluate the immunohistochemical expression of the ING3 in actinic cheilitis and squamous cell carcinoma of the lower lip. METHODS: Forty-five specimens of actinic cheilitis and 48 specimens of squamous cell carcinoma of the lower lip were submitted to immunohistochemical detection of ING3. The protein expression in different cellular sublocations was compared between the two groups, and associations with the clinicopathological variables were analyzed. A significance level of 5% was adopted for all tests. RESULTS: Deaths were significantly more frequent in tumors with a high histopathological risk score (p < 0.05). In actinic cheilitis, significant differences were found in the nucleus-cytoplasmic expression of ING3 and expression restricted to the cytoplasm with binary histopathological grading (p < 0.05). In squamous cell carcinoma of the lower lip, there was no statistically significant difference when comparing ING3 expressions with clinical and morphological parameters (p > 0.05). Nucleo-cytoplasmic ING3 expression was significantly lower in squamous cell carcinoma of the lower lip when compared to actinic cheilitis (p < 0.05) and the expression restricted to the cytoplasm was significantly higher in squamous cell carcinoma of the lower lip (p < 0.05). CONCLUSION: The results of this study suggest that there is a marked decrease in the nuclear expression of ING3 as malignant progression occurs, indicating an impaired tumor suppressor function of this protein in actinic cheilitis and squamous cell carcinoma of the lower lip.

IMP3, CDK4, MDM2 and ß-catenin expression in Enchondroma and Central Chondrosarcoma: Diagnostic and prognostic utility.

INTRODUCTION: The role of IMP3, CDK4, MDM2 and ß-catenin proteins in Enchondroma and Central Chondrosarcoma is not totally understood. The aim of this study is to evaluate the immunoexpression of these proteins, associating histological grade, clinical data and prognosis to these tumors. METHODS: This is a retrospective-analytical study of 32 Enchondroma and 70 Central Chondrosarcoma. RESULTS: IMP3, CDK4, MDM2 and ß-catenin expression was observed in 22.82 %, 13.82 %, 17.17 % and in 8.8 % of cases, respectively. All Enchondromas positive for these immunomarkers were located in short tubular bones. The positivity for these antibodies is directly proportional to Chondrosarcoma's histological grade increase. No difference was found between Enchondroma and Chondrosarcoma, Grade 1 for IMP3, CDK4 and ß-catenin positivity. Significant metastasis outcome was observed for IMP3, CDK4, MDM2 and death for MDM2 expression. CONCLUSION: IMP3, CDK4, MDM2 and ß-catenin expression in Enchondromas of short bones phenotypically characterizes these tumors. Their expression has not proven to be useful either as diagnostic markers of these neoplasms or in distinguishing between Enchondroma and Chondrosarcoma, Grade 1. The significant immunoexpression of IMP3, CDK4 and MDM2 in metastatic Chondrosarcoma and the lower survival in those with positivity for MDM2 suggest a possible association of these proteins with tumor aggressiveness.

Immunostaining for Mismatch Repair Complex Proteins Impacts on Clinical-Pathological Characteristics and Prognosis of Adenoid Cystic Carcinoma of Salivary Glands.

OBJECTIVE: To evaluate the influence of MMR proteins on clinicopathological characteristics and prognosis of salivary gland adenoid cystic carcinoma (ACC). METHOD: The solid pattern of ACC showed lower expression for MSH2 (p = 0.039). Significant imbalance in MSH2/MSH6 immunostaining was observed in all histological patterns (p < 0.001), and imbalance in PMS2/MLH1 immunostaining was observed in the cribriform pattern (p = 0.011). The presence of capsule was associated with high expression of MSH6 (p = 0.019), MLH1 (p = 0.045) and PMS2 (p = 0.009). The absence of cribriform pattern (p = 0.002) and capsule pattern (p = 0.025), as well as low expression for MSH6 (p = 0.006) and PMS2 (p = 0.037) were associated with lower overall survival. In multivariate analysis, loss of MSH2 (p = 0.039) and MLH1 (p = 0.017) were significantly associated with worse overall survival. RESULTS: Twenty-four ACC were clinical-pathologically evaluated and we perform immunohistochemistry for MSH2, MSH6, PMS2 and MLH1. Percentage counting of positive cells was performed in 10 fields of each histological pattern (cribriform, tubular and solid) and the averages of the 30 fields were considered for evaluation with other clinical-pathological variables (Kruskal-Wallis/Dunn, Friedman/Dunn, chi-square, Log-Rank Mantel-Cox tests and Cox regression; SPSS v20.0, p < 0.05). DISCUSSION: Salivary glands' ACC shows imbalance of the MMR complex and loss of expression of its components is associated with the overall survival of these patients.

Myofibroma with Atypical Features can Mimic Low-Grade Myofibroblastic Sarcoma: Two Paediatric Cases.

Myofibroma is a rare benign mesenchymal tumor that frequently affects the pediatric population with a predilection for the head and neck region. About 10% of myofibroma cases, presenting atypical features, can be misinterpreted as low-grade myofibroblastic sarcoma (LGMS), with therapeutic and prognostic impact. Here, we report two pediatric cases of benign myofibroblastic tumors, one of them showing typical characteristics of myofibroma, the other was an atypical myofibroma, which initially mimicked low-grade myofibroblastic sarcoma. Atypical myofibromas, despite its distinctive characteristics, follow a benign course, similar with typical myofibroma. It is necessary to distinguish atypical myofibroma from low-grade myofibroblastic sarcoma and avoid unnecessary invasive therapy.

Encephalomyelitis and serositis caused by Chlamydia pecorum in buffalo calves from Brazil.

Chlamydia pecorum causes subclinical infections in cattle, but sporadic, bovine encephalomyelitis cases have been reported in calves and documented in two instances in European buffalo. An outbreak of Chlamydia pecorum-induced encephalomyelitis and serositis occurred in 3-month-old buffalo calves from Brazil. Initially presenting with pelvic limb incoordination, the calves progressed to lateral recumbency, depression, and death. Necropsies of two calves revealed encephalomyelomalacia, fibrin deposition on the external surface of the pericardium (case 1) and pleural and pericardial fibrosis (case 2). Microscopically, a multifocal to coalescing, necrotizing, neutrophilic and lymphocytic meningoencephalomyelitis with fibrinoid vasculitis and thrombosis was present. Anti-Chlamydia antibody labeling was demonstrated by immunohistochemistry. Bacteriological examination yielded no pathogenic bacteria in the brain or lungs. Chlamydia pecorum was confirmed by PCR. This work describes the gross, histopathological, microbiological, and molecular findings in two cases from an outbreak of Chlamydia pecorum-induced disease in buffalo calves.

Tongue Metastasis of Mucinous Colorectal Adenocarcinoma: Report of a Rare Case.

Metastases in the oral and maxillofacial region, particularly in soft tissues, are exceedingly rare. Such metastases can present as swelling in older individuals, especially in the tongue and gingiva. Furthermore, colorectal metastases at this site are commonly found in the mandible and gingiva and usually share the same morphology as the primary tumor. Herein, we report the case of a 61-year-old woman with a metastatic nodule in the tongue covered by normal mucosa. The clinical, histopathological, and immunohistochemical findings were essential for the final diagnosis of colorectal metastasis, consistent with adenocarcinoma with mucinous differentiation and intestinal phenotype. Metastases of colorectal adenocarcinoma to the tongue are rare but should be included in the differential diagnosis of nodular lesions at this site. The diagnosis can therefore be made based on meticulous clinical and histopathological examination complemented by immunohistochemistry.

Energy Metabolic Profile in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma: A Preliminary Landscape of Warburg Effect in Oral Cancer.

We hypothesized that cell energy metabolic profiles correlate with normal, dysplastic, and tumor cell/tissue statuses and may be indicators of aggressiveness in oral squamous cell carcinoma (OSCC) cells. The energy-related proteins that were differentially expressed in human OSCC fragments (n = 3) and their adjacent epithelial tissue (TAE) were verified using mass spectrometry (MS). Immunohistochemistry for 4-hydroxynonenal (4-HNE) was performed to evaluate the oxidative stress patterns in OSCC (n = 10), epithelial dysplasia (n = 9), and normal epithelial (n = 4) biopsies. The metabolic energy profile of OSCC aggressiveness was investigated in human OSCC cell lines with different levels of epithelial-mesenchymal transition proteins. The genes associated with the proteins found by MS in this study were analyzed using survival analysis (OS), whereas the genes associated with a poorer prognosis were analyzed using context-specific expression, Gene Ontology (GO) and Cancer Hallmarks for function enrichment analysis. The rationale for all experimental approach was to investigate whether the variation in energy metabolism profile accompanies the different phenotypes (from epithelial to mesenchymal) during the epithelial-mesenchymal transition. All OSCC fragments exhibited an increase in glycolysis-related proteins and a decrease in mitochondrial activity compared to the TAE region (p < 0.05), probably due to the downregulation of pyruvate dehydrogenase and antioxidant proteins. Additionally, the OSCC cell lines with a mesenchymal profile (SCC4, SCC9, and SCC25) had a lower mitochondrial mass and membrane potential and generated lower levels of reactive oxygen and nitrogen species than the TAE region. When we analyzed 4-HNE, the reactive species levels were increased in the epithelial regions of OSCC and potentially malignant lesions. A decrease in the levels of 4-HNE/reactive species was observed in the connective tissue underlying the dysplastic regions and the OSCC invasion zone. Based on this scenario, aggressive OSCC is associated with high glycolytic and oxidative metabolism and low mitochondrial and antioxidant activities, which vary according to the differentiation level of the tumor cells and the stage of carcinogenesis.

Evaluation of epithelial-to-mesenchymal transition and Ki-67 index in aggressive papillary thyroid cancer.

OBJECTIVES: The present study aims to characterize immunohistochemical features of markers associated with Epithelial-Mesenchymal Transition (EMT) and proliferative activity that could lead to death in Papillary Thyroid Cancer (PTC). METHODS: Clinical data and tumor material were retrospectively collected. The patients were separated into death from PTC (Group 1), metastatic cases with indolent behavior (Group 2) and non-metastatic indolent PTC (Group 3). Immunohistochemical assessment of E-cadherin, ß-catenin, Vimentin, ZEB-1 and Ki-67 was performed in each tumor and a semiquantitative estimation of the percentage of expression was fulfilled on the best marking area at high of the tumor invasion front. RESULTS: 31 patients were included, 15 that died from PTC (Group 1), 6 in Group 2 and 10 in Group 3. The proliferative marker Ki-67 showed a significant difference in its expression in the tumor invasion front between the groups, specifically between groups 1 and 3 (p = 0.006). On the other hand, EMT-related immunohistochemical markers did not show significant difference in their percentage of expression, since loss of E-cadherin, ß-catenin and Vimentin was observed in most cases at the invasion front. CONCLUSION: Patients that died from PTC had a significantly higher Ki-67 labelling index compared to patients with indolent disease (cutoff of 11%). Ki-67 may have a role as a prognostic marker and could be considered for routine use in PTC.

Presence of Merkel cell polyomavirus DNA and large-T antigen in keratinocyte carcinomas and its correlation with immunohistochemical markers p16, p53 and ki67

Abstract Background Merkel cell polyomavirus (MCPyV), a human polyomavirus that is unequivocally linked to merkel cell carcinoma (MCC), has been found in association with keratinocytes carcinomas (KC), especially basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC). Nevertheless, there is scarce information about the possible involvement of MCPyV in the development of KC. Objectives To assess the presence of MCPyV DNA and Large-T Antigen (LT-Ag) via Polymerase Chain Reaction (PCR) and Immunohistochemistry (IHC) in cases of KC, and to correlate its presence with immunohistochemical markers p16, p53, and ki67, tumor type and subtype, sun-exposed location, and epidemiological data. Methods The prevalence of MCPyV DNA, LT-Ag, and immunohistochemical markers p16, p53, and ki67 was assessed by PCR and Immunohistochemistry (IHC) in 127 cases of KC, these results were correlated with tumor type and subtype, sun-exposed location, and epidemiological data. Results The MCPyV DNA was detected in 42.57% (43 of 101) cases by PCR, the LT-Ag was detected in 16.4% (20 of 122) of cases, p16 in 81.5% (97 of 119), p53 in 66.4% (83 of 125), ki67 in 89% (73 of 82). No correlation between MCPyV LT-Ag and DNA confronted with tumor type, subtype, location site, and immunohistochemical markers was found. A single correlation between the MCPyV LT-Ag and cSCC tumors and peri-tumoral lymphocyte cells was noted. Study limitations Further steps need to be taken to better evaluate the MCPyV influence and its possible role in KC carcinogenesis, as the evaluation of the virus genome state, the gene sequence that encodes LT-Ag in the KC tumor cells, and in situ hybridization for viral DNA or RNA in these cells. Conclusions Despite the frequent detection of MCPyV in KC, the data available so far does not support the hypothesis of a causal relationship between them.

Cryopreservation of canine ovarian tissue by slow freezing and vitrification: Evaluation of follicular morphology and apoptosis rate.

In this study, we aimed to evaluate the efficacy of cryopreserving canine ovarian tissue using vitrification and slow freezing methods while investigating potential differences in cryotolerance based on follicular type and cryopreservation technique. Twenty-eight ovaries were collected from 14 anoestrus bitches of various breeds, aged between 2 and 5 years, and undergoing elective ovariohysterectomy. The ovaries were sectioned into small fragments and randomly assigned to three groups: vitrification, slow freezing, and a control group (fresh tissue). Vitrification was performed using cryotubes containing DAP 213 solution (2M DMSO, 1M acetamide, 3M propylene glycol) in two stages, while slow freezing involved cryotubes with 1.5M DMSO solution inserted into a programmable machine. The effects of cryopreservation were evaluated by histology and immunohistochemistry (cleaved caspase-3), to determine the percentage of cells undergoing apoptosis. Histological examination revealed that the slow freezing group exhibited a significantly higher percentage of intact follicles (45.75 %) compared to those subjected to vitrification (38.17 %; P = 0.01). Immunohistochemical evaluation further indicated that 84.21 % of the follicles in the slow freezing group did not express caspase-3, suggesting the absence of apoptosis. Conversely, vitrified samples exhibited significantly more apoptotic cells compared to other groups (P < 0.001). Furthermore, early antral follicles displayed a higher susceptibility to degeneration regardless of the cryopreservation method employed. Nevertheless, when comparing the cryopreserved groups, early antral follicles showed greater degeneration in slow freezing group, while preantral follicles were the most affected in the vitrification group. In conclusion, slow freezing demonstrated superior preservation of viable follicles compared to vitrification and emerged as the preferred technique for cryopreserving canine ovarian tissue. These findings contribute valuable insights into optimizing cryopreservation methods for canine ovarian tissue, potentially benefiting reproductive technologies and fertility preservation in canines.

Follicular thyroid carcinoma in an inbred family of mongrel dogs in Trinidad & Tobago.

Thyroid tumors occur in many domestic species, but are most common in the dog, in which they are classified as follicular or medullary. During 2012-2016, we received tissue specimens or whole carcasses of 4 dogs with variable enlargement of the thyroid glands. The 2 males and 2 females were of mixed (mongrel) inbreeding, 3-4.5-y-old. All tumors had lobulated architecture forming follicular structures variably containing colloid. On immunohistochemistry of the tumors from 3 of the dogs, 2 were thyroglobulin positive, and all 3 were negative for calcitonin, confirming follicular thyroid carcinoma in 2 of the dogs. Thyroid carcinomas have not been reported previously in related mongrel dogs, to our knowledge.

Osteopontin, WNT3A, and ABCB5 Biomarkers Expression in Osteosarcoma Patients.

Objective This study aimed to correlate the expression, by immunohistochemistry, of the proteins OPN, ABCB5, and WNT3A from anatomopathological materials obtained from paraffin blocks, slides, or both, from patients with osteosarcoma (OS), analyzing epidemiological characteristics, as well as their presence and influence on the evolution and progression of the disease. Methods After the initial case selection, we searched for the respective paraffin blocks and took only those with sufficient tumor mass to allow additional sections with no complete loss of biological material. The sarcoma area identification in representative paraffin blocks used multisample blocks (tissue microarray [TMA]) created on a BenchMark ULTRA (Roche Diagnostics Corporation, Indianapolis, IN, USA) instrument. Then, we analyzed the association between the expression of ABCB5, WNT3A, and osteopontin (OPN) markers with the variables age, location, and tissue type (Fisher exact test/Chi-squared test). Results The average age of the patients was 23 years, and the rate of males and females was the same. We analyzed 40 slides from 28 OS patients seen from 2005 to 2017. Their follow-up time was 80.0 months, and the 5-year survival rate was 46.7%. Most metastases occurred in lung tissue (92.9%). Proteins ABCB5, OPN, and WNT3A did not present statistical significance when compared with age group, neo-adjuvant, adjuvant, or both, chemotherapy, location, survival, or death. Osteopontin was negative in all samples. WNT3A expression occurred in patients who died early. Conclusion In an immunohistochemical study, ABCB5, OPN, and WNT3A did not have statistical significance. In the parameters analyzed, they did not seem to be a predictive or aggressive factor for OS.

Immunolocalization of Aquaporin 1, 2, and 9 in Anuran Testis of the Neotropical Pointedbelly Frog Leptodactylus podicipinus.

Many anuran survival strategies involve hydric regulation, and reproduction is not different. The aquaporin (AQP) family plays an important role in water transport and regulation in many tissues, including the male gonad. The testes undergo various stages of change during the reproductive cycle, and water balance is an important factor for ensuring reproductive success. Considering the relevance of water control in testicular development in anurans and the lack of research regarding the tissue localization of AQP in the male gonad, the present study investigated the expression of three AQPs (1, 2, and 9) in the testis of the neotropical anuran species Leptodactylus podicipinus during two different periods of the reproductive cycle (reproductive and non-reproductive). AQP1 and 2 immunoreactions were found in early germ cells, spermatozoa, Leydig cells, and Sertoli cells, which were more frequently expressed within the reproductive period. AQP1 was also found in the testicular blood vessels. AQP9 was identified predominantly in the epithelium of the intratesticular ducts of reproductive-period individuals. This study presents, for the first time, the localization of AQP1, AQP2, and AQP9 in the testes of an anuran species and the differences in their location during two distinct periods of the reproductive cycle.

Striated Duct Adenoma: A Case Report and a Scoping Review.

INTRODUCTION: Striated duct adenoma (SDA) is a rare benign salivary gland tumor with a recently described genetic signature. Recurrent oncogenic mutations affecting the IDH2 gene differentiate SDA from its primary differential diagnosis of canalicular adenoma. Here, we report a case of SDA affecting the parotid gland with IDH1/2 mutation-specific immunohistochemical positivity. Additionally, we provide a scoping review developed according to the Cochrane Methodology and reported following the Joana Briggs Institute (JBI) checklist to synthesize all previously published cases of SDA. The review protocol was registered on the Open Science Framework (OSF) platform ( https://osf.io/7mztg ). The searches were performed using Medline, Embase, Web of Science, and LILACS, with no date or language limit. Studies were evaluated for eligibility, extracted, and compiled in a narrative form. Seven studies with 20 patients with SDA, including ours, were analyzed. The tumors mainly affected the parotid gland (13/20) in patients with a mean age of 62 years and did not display sex predilection. Swelling was the leading clinical symptom. The mean follow-up duration was 26 months with no recurrence or metastasis after resection. CONCLUSION: Awareness of the clinicopathological features and the use of IDH1/2 mutation-specific immunohistochemistry are pivotal for the consistent identification of SDA, and assessment for true biological potential will require increased follow-up and scrutiny.

Elevada expressão de galectina-3 em cicatrizes excessivas: Um estudo piloto / Elevated expression of galectin-3 in excessive scars: A pilot study

Introdução: Cicatrizes hipertróficas e queloides são tipos de cicatrizes excessivas de cicatrização anormal da pele. Galectina-3 (gal-3) é uma proteína da família das lectinas capaz de identificar carboidratos, que podem se combinar e atuar em diversas moléculas. Na literatura, a ação da gal-3 como principal agente regulador da fibrogênese já foi descrita, sendo atualmente utilizada na terapia antifibrótica de diversos órgãos como pulmão e fígado. O objetivo deste estudo piloto foi mostrar resultados preliminares encontrados na expressão de gal-3 em cicatrizes exacerbadas. Método: Foram coletadas 20 amostras de biópsias de cicatrizes excessivas (16 queloides e 4 cicatrizes hipertróficas) e 9 amostras de cicatrizes normais de 22 mulheres e 7 homens. Essas amostras foram processadas para análise histopatológica de rotina por imuno-histoquímica para detectar gal-3. As células positivas para gal-3 foram quantificadas pelo método estereológico utilizando uma grade de 36 pontos. Resultados: A imuno-histoquímica mostrou alta expressão de gal-3 em células endoteliais e epiteliais de todas as amostras de cicatrizes, bem como expressão em células distribuídas pela derme. Maior expressão de gal-3 foi encontrada em amostras de queloides (28% de células positivas) em comparação com cicatrizes normais (18%) e hipertróficas (22%) (p=0,0075). Os resultados foram obtidos de um pequeno número de pacientes, por se tratar de um estudo piloto. Conclusão: Os dados sugerem que a gal-3 participa do processo de cicatrização e, devido à sua maior presença em amostras de queloides, pode ser um potencial biomarcador para formação de queloides e um alvo terapêutico promissor a ser explorado.

Introduction: Hypertrophic scars and keloids are types of excessive scars from abnormal skin healing. Galectin-3 (gal-3) is a protein from the lectin family capable of identifying carbohydrates, which can combine and act on different molecules. In the literature, the action of gal-3 as the main regulatory agent of fibrogenesis has already been described and is currently used in anti-fibrotic therapy for various organs such as the lung and liver. The objective of this pilot study was to show preliminary results found in the expression of gal-3 in exacerbated scars. Method: Twenty biopsy samples from excessive scars (16 keloids and 4 hypertrophic scars) and 9 samples from normal scars were collected from 22 women and 7 men. These samples were processed for routine histopathological analysis by immunohistochemistry to detect gal-3. Gal-3 positive cells were quantified by the stereological method using a 36-point grid. Results: Immunohistochemistry showed high expression of gal-3 in endothelial and epithelial cells of all scar samples, as well as expression in cells distributed throughout the dermis. Higher gal-3 expression was found in keloid samples (28% positive cells) compared to normal (18%) and hypertrophic (22%) scars (p=0.0075). The results were obtained from a small number of patients, as this was a pilot study. Conclusion: The data suggest that gal-3 participates in the healing process and, due to its greater presence in keloid samples, it may be a potential biomarker for keloid formation and a promising therapeutic target to be explored.

Oral T-cell-rich large B-cell lymphoma in a horse.

Lymphoma is the most common tumor of hematopoietic origin in horses. The course of the disease and clinical signs vary greatly, depending on tumor location and extent. The aim of this report is to describe the occurrence of T-cell-rich oral large B-cell lymphoma with marked local infiltration in a 25-year-old Crioula mare. The mare showed an increase in volume on the right side of its face, dyspnea, anorexia, and progressive weight loss. The clinical assessment showed that the lesion was located in the rostral and caudal sinuses and was markedly invasive to adjacent structures. The autopsy revealed a yellow mass with a soft to firm consistency, infiltrating multiple bones in the skull, and extensively invading the hard palate and masseter muscle. Histologically the mass comprised an undifferentiated malignant neoplasm characterized by a densely cellular neoplasm composed of large CD20 + neoplastic B-lymphocytes admixed with sheets of small, CD3 + reactive T-lymphocytes supported by delicate fibrovascular stroma leading to the diagnosis of oral T-cell-rich large B-cell lymphoma.

A comparative exploration of immunohistochemical markers in patients with papulopustular rosacea undergoing treatment with oral isotretinoin versus doxycycline.

BACKGROUND: Rosacea is a chronic inflammatory disease, and doxycycline is a widely recommended treatment for it due to its anti-inflammatory action. Oral isotretinoin reduces sebaceous gland activity and modulates toll-like receptors, reducing inflammation. Our aim was to investigate the effect of these two drugs on the expression of cutaneous immunohistochemical biomarkers related to etiopathogenic factors involved in rosacea. METHODS: We conducted a randomized, comparative, and evaluator-blinded trial, including 40 participants with moderate and severe papulopustular and ocular rosacea. Participants were treated with doxycycline (DOXY) 100 mg or isotretinoin (ISO) 0.3 mg/kg daily. Immunohistochemistry at baseline and after 4 months was used to demonstrate the expression of the biomarker on the affected skin. RESULTS: The following changes were detected: a reduction in the vessel count after using VEGF with DOXY (P = 0.010); a decrease in VEGF intensity with ISO (P < 0.001) and DOXY (P = 0.020); a reduction of nitric oxide synthase enzyme with both drugs in the inflammatory infiltrate (ISO P < 0.001; DOXY P = 0.003); however, only with ISO was there a significant (P = 0.030) decrease at the level of the sebaceous glands, indicating a reduction of nitric oxide synthesis; a reduction of TRPV-1 expression at the level of the sebaceous glands was observed only with DOXY (P = 0.041); a decrease of cathelicidin LL37 expression, a key antimicrobial peptide in the etiopathogenesis of rosacea, was noted with both drugs, although at the level of sebaceous glands, only with DOXY (P = 0.007). CONCLUSIONS: Oral isotretinoin and doxycycline have modified the expression of cutaneous biomarkers related to rosacea etiopathogenesis, demonstrating their role in controlling inflammatory and vascular processes.

Immunohistochemistry and RT-PCR as ancillary tools in the diagnosis of acquired oral syphilis.

OBJECTIVE: To investigate Treponema pallidum detection using immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) assays in acquired oral syphilis (AOS). MATERIALS AND METHODS: Thirty-seven paraffin-embedded tissue specimens of AOS (32 secondary and five primary) were analyzed, integrating double-positive serological results with clinicodemographic and histopathological data. T. pallidum presence was semiquantitatively assessed by IHC, while RT-PCR targeted T. pallidum DNA. Sensitivity, specificity, and the area under the curve (AUC) were calculated with 95% confidence intervals (CI). RESULTS: The study included mostly females (62.2%) with a mean age of 27.1 years. T. pallidum was detected in all samples by IHC, predominantly in the epithelium across all layers (43.2%). RT-PCR identified T. pallidum DNA in 32 cases, with negative results observed in cases of secondary AOS. The AUC for IHC versus disease stage was 62.5% (95% CI: 45.1-77.8), and for RT-PCR, it was 57.8% (95% CI: 40.5-73.8). The AUC comparing IHC to RT-PCR was 83.8% (95% CI: 67.9-93.8). CONCLUSION: This study represents the first attempt to evaluate the proposed direct detection algorithm for AOS. IHC and RT-PCR serve as ancillary tools for detecting T. pallidum in both primary and secondary stages of AOS.