Hemangiosarcoma is a mesenchymal neoplasm originating in the endothelial cells of blood vessels; they can be classified as non-visceral and visceral types. Non-visceral hemangiosarcomas can affect the skin, subcutaneous tissues, and muscle tissues; visceral hemangiosarcomas can affect the spleen, liver, heart, lungs, kidneys, oral cavity, bones, bladder, uterus, tongue, and retroperitoneum. Among domestic species, dogs are most affected by cutaneous HSA. Cutaneous HSA represents approximately 14% of all HSA diagnosed in this species and less than 5% of dermal tumors, according to North American studies. However, Brazilian epidemiological data demonstrate a higher prevalence, which may represent 27 to 80% of all canine HSAs and 13.9% of all skin neoplasms diagnosed in this species. Cutaneous HSA most commonly affects middle-aged to elderly dogs (between 8 and 15 years old), with no gender predisposition for either the actinic or non-actinic forms. The higher prevalence of cutaneous HSA in some canine breeds is related to lower protection from solar radiation, as low skin pigmentation and hair coverage lead to greater sun exposure. Actinic changes, such as solar dermatosis, are frequent in these patients, confirming the influence of solar radiation on the development of this neoplasm. There are multiple clinical manifestations of hemangiosarcoma in canines. The diagnostic approach and staging classification of cutaneous HSAs are similar between the different subtypes. The definitive diagnosis is obtained through histopathological analysis of incisional or excisional biopsies. Cytology can be used as a presurgical screening test; however, it has little diagnostic utility in cases of HSA because there is a high risk of blood contamination and sample hemodilution. Surgery is generally the treatment of choice for dogs with localized non-visceral HSA without evidence of metastatic disease. Recently, electrochemotherapy (ECT) has emerged as an alternative therapy for the local ablative treatment of different neoplastic types; the use of radiotherapy for the treatment of dogs with cutaneous HSA is uncommon. There is greater consensus in the literature regarding the indications for adjuvant chemotherapy in subcutaneous and muscular HSA; doxorubicin is the most frequently used antineoplastic agent for subcutaneous and muscular subtypes and can be administered alone or in combination with other drugs. Other therapies include antiangiogenic therapy, photodynamic therapy, the association of chemotherapy with the metronomic dose, targeted therapies, and natural products. The benefits of these therapies are presented and discussed. In general, the prognosis of splenic and cardiac HSA is unfavorable. As a challenging neoplasm, studies of new protocols and treatment modalities are necessary to control this aggressive disease.

Cyanoacrylate-based adhesives are widely used in wound closure, providing good cosmetic results and little discomfort. However, reports in the literature are found about negative effects that include the release of cytotoxic chemicals during biodegradation. In this study, we sought to evaluate and compare the effectiveness of four cyanoacrylate-based adhesives on the closure of skin incisions in Rattus norvegicus. The animals (n = 140) were divided into five groups of 28 animals each according to the wound closure technique: G1 and G2 (n-2-ethyl-cyanoacrylate); G3 (n-2-butyl-cyanoacrylate); G4 (n-2-octyl-cyanoacrylate); and G5 (5 nylon stitches). Midline incisions measuring 5.0 cm in length were created and closed using the different materials evaluated, and on D3, D7, D14, and D21, tensiometric and histopathological analyses were performed. Shorter wound closure and adhesion times were observed in G4 animals. At D3 and D7, G5 presented greater tensiometric resistance in the animals of G5, with a decrease in D14 and D21 compared to the other groups. On the other hand, the wounds of G3 and G4 were more resistant in D14 and D21, reaching maximum resistance values. Polymorphonuclear and mononuclear cells are more prevalent and more granulation tissue was observed in G5. The deposition of type III collagen was more evident in G5, whilst there was no difference in the amount of type I collagen in any of the groups treated with cyanoacrylate adhesives. Larger areas stained positive for VEGF-α in G2 and smaller areas in G4, with peaks at D7 and D14. In general, cyanoacrylate adhesives cause less intense inflammatory reactions, resulting in shorter healing times when compared to nylon sutures.

Apocrine gland anal sac adenocarcinoma is an aggressive neoplasm, and surgery remains the treatment of choice, although it is controversial in advanced cases. The prognostic factors are not well established. Human Epidermal Growth Factor Receptor 2 (HER2) is a membrane protein related to tumorigenesis, whereas Ki67 is a nuclear protein related to cell proliferation. Both are potential prognostic markers and therapeutic targets. This study aimed to evaluate the expression of HER2 and Ki67 markers in canine apocrine gland anal sac adenocarcinoma. The tumor samples were divided into four groups: largest tumor diameter less than 2.5 cm, largest tumor diameter greater than 2.5 cm, metastatic lymph nodes, and control group of non-neoplastic anal sacs. Each contained 10 samples. Immunohistochemistry was performed to verify the expression of HER2 and Ki67 markers. Positive HER2 staining was observed in 45% of the neoplastic cases and negative HER2 staining in 100% of the control group. The Ki67 expression had a median of 25% in all groups, except for the control group, which had a median of 8%. The HER2 and Ki67 expression was present in apocrine gland anal sac adenocarcinoma, making them potential therapeutic targets. However, it was not possible to determine the clinical value of either marker.

Determining cell proliferation rates and tumor apoptosis through immunohistochemistry allows the evaluation of the biological behavior of the tumor, optimizing the patient’s clinical course. This study aimed to analyze the immunohistochemical expression of Ki-67, COX-2 and caspase-3 and correlate them with the type of response to ECT in feline cutaneous squamous cell carcinoma (SCC), thus determining the predictive potential of these variables. For this, 13 samples of feline cutaneous SCC were evaluated before ECT, and statistical analyses of the correlation intensity between the variables were performed using the Spearman correlation coefficient, with a significance level of 95%. The results indicate a significant negative correlation between histopathological grade and response to ECT (ρ=-0.6; p=0.03); there was no significant correlation between Ki-67, COX-2 and caspase-3 immunoexpression with the response to ECT (ρ=-0.18; p=0.54/ρ=-0.23; p=0.44/ρ=-0.12; p=0.69, respectively). Therefore, the study shows that the histopathological grade, tumor size and staging, degree of cellular pleomorphism and degree of inflammatory infiltrate can be considered negative prognostic factors for cutaneous SCC and negative predictors for response to ECT. However, the markers Ki-67, COX-2 and caspase-3 are not considered predictive factors for the type of response to ECT. In addition, no relationship between these immunoexpressions and greater tumor aggressiveness was observed. The SCCs evaluated in this study showed significant COX-2 labeling, indicating a potential therapeutic target. ECT has been shown to be safe and effective for local control of feline cutaneous SCC but with reduced effectiveness in larger and invasive lesions.

Resumo Defeitos de grandes segmentos traqueais podem apresentar sério problema clínico, devido à ausência de substitutos na cirurgia reconstrutiva. Os biomateriais poliméricos estão entre os mais utilizados na medicina. Entretanto, a implantação de um biomaterial desencadeia uma série de eventos biológicos e a biocompatibilidade do material é de extrema importância para a medicina regenerativa. Objetivou-se com este estudo avaliar o uso da copoliamida associada ao elastômero termoplástico (PCTPE) em próteses impressas em 3D para reparação de defeitos parciais da traqueia de coelhos. Foram utilizados 16 coelhos machos da raça Nova Zelândia Branco, submetidos à criação de um defeito parcial de traqueia na região ventral do 4º ao 8º anel traqueal. Os animais foram subdivididos (n=4) de acordo com o momento das eutanásias, programadas com intervalo de sete (G7), quinze (G15), trinta (G30) e sessenta dias (G60). A análise histopatológica por hematoxilina e eosina (HE) revelou que o implante 3D de PCTPE apresentou reação do tipo corpo estranho e a inflamação persistiu até os 60 dias de avaliação. A histoquímica de picrosirius vermelho revelou tendência de maior quantidade de colágeno tipo I nos tempos iniciais de inflamação, enquanto o colágeno tipo III foi predominante nos períodos tardios de avaliação. Pode-se sugerir reação exacerbada e não adequada da interface tecido-material e perpetuação do processo inflamatório.

Cyanoacrylate-based adhesives are commonly used for wound closure due to their short synthesis time, aesthetic outcomes, and minimal discomfort. However, reported adverse effects include the release of cytotoxic metabolites, inflammation, and foreign body reactions. This study evaluated and compared the effectiveness of three cyanoacrylate-based adhesives for skin incision closure in Rattus norvegicus. The subjects were divided into three groups based on the type of monomer: G1 (n-2-ethyl-cyanoacrylate), G2 (n-2-butyl-cyanoacrylate), and G3 (n-2-octyl-cyanoacrylate). Each animal received two 2 cm paramedian incisions, which were closed using either a topical over dermal (OD) or a topical transdermal (TD) application, resulting in two subgroups per group. Wounds were evaluated on postoperative days 3, 7, 14, and 21 to compare the different monomers and application techniques. Assessment of the inflammatory infiltrate revealed differences in polynuclear cells between the TD and OD on days 3 and 7, while TD demonstrated improved results in mononuclear cells at all time points. Sustained inflammatory processes and foreign body reactions were observed. Quantification of tumor necrosis factor (TNF-α) and thiobarbituric acid reactive substances (TBARS) indicated that TD maintained stability throughout the assessment periods, though it exhibited higher values than OD from days 7 to 21. These higher values were associated with a foreign body reaction and increased oxidative stress. Regarding tissue formation, OD produced more aligned wound edges, supporting the production of types I and III collagen and improving scar resolution compared to TD. Our findings indicate that the patch application technique has a greater impact on healing than the size of the cyanoacrylate monomer.