Squamous Cell Carcinoma in a Pig

 Background: Squamous cell carcinoma (SCC) is a malignant neoplasm of epidermal cells that exhibits keratinocyte differentiation. These neoplasms are common in dogs, cats, horses, and cattle, relatively uncommon in sheep, and rarely affect goats and pigs. There are several factors that are associated with the development of SCC, including prolonged exposure to ultraviolet light, lack of pigment in the epidermis, and sparse coating or lack of fur at the affected sites. The aim of this study was to report the occurrence of squamous cell carcinoma in a domestic pig.Case: A surgically removed nodule from the left ear of a female, light-colored, three-year-old pig, which breed was not defined, was submitted for histopathological analysis. The sample was fixed in 10% formalin, analyzed macroscopically, routinely processed for histology, sectioned at five microns and stained with hematoxylin and eosin. Additionally, anticytokeratin (AE1/AE3) and anti-vimentin immunohistochemical assays were performed. All additional information was provided by the animal’s owner. According to the history obtained, the animal belonged to a herd made up of five females and one boar. For four months, multiple nodules started to grow on the outer surface of the pig’s ear and in many occasions exhibited ulceration and bleeding. One of the nodules was submitted for histopathology examination. Macroscopically it measured 3 cm in diameter, had an irregular and ulcerated surface, and a wide base. Cut surface had a firm consistency and whitish color. Microscopic examination revealed proliferation of neoplastic epithelial cells arranged in islands and trabeculae, with slightly eosinophilic cytoplasm, pleomorphic, round, reniform nucleus, with loose chromatin and 1-3 nucleolus. Mitotic figures were infrequent. In the central area of the islands, there was individual cell keratinization. There was a moderate, fibrovascular supporting stroma with intense inflammatory infiltrate composed of lymphocytes, plasma cells and eosinophils. Anti-cytokeratin (AE1/AE3) immunohistochemical assay (IHC) revealed a strong diffuse positive staining on the cytoplasm of tumoral epithelial cells, and anti-vimentin IHC showed positive staining on the supporting tissue cells (fibroblasts and endothelial cells).Discussion: The diagnosis of squamous cell carcinoma in this pig was based on clinical and pathological findings since it was observed proliferation of neoplastic epithelial cells often forming “keratin pearls” and immunohistochemistry positive for cytokeratin was immunostaining in the cytoplasm of tumor cells. Information on the occurrence of SCC in pigs is scarce in the literature, especially in Brazil. In a survey of neoplasms in farm animals in Southern Rio Grande do Sul with cases from 1978 to 2002, neoplasms in pigs represented 0.6% of the diagnoses when compared to the number of neoplasms in cattle and horses. The low number of cases in this species is due to the fact that a large proportion of the population is slaughtered at a young age and therefore the chances to develop neoplasms are lower. The main SCC growth sites include areas deprived of hair, especially in animals with unpigmented skin. In the pig described here, the neoplasm was located on the outer surface of the ear, which was exposed to ultraviolet rays. Granuloma, papilloma, and basal cell tumor should be considered in the list of differential diagnosis when SCC is suspected. Neoplasms in pigs are scarcely reported.Keywords: neoplasm, carcinoma, pig, immunohistochemical

Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used