Ganglioneuromatosis of the Gallbladder in a Dog with Cholecystitis and Cholestasis.

A 2-year-old entire female mixed-breed dog was presented with signs of cholestasis. Abdominal ultrasonography revealed a gallbladder with a thickened and hyperechoic wall and luminal calculi. Exploratory laparotomy with cholecystectomy was performed and histopathological examination of the specimens from the cholecystectomy demonstrated extensive proliferation of large, prominent nerves containing ganglion cells with no atypia mainly located in the gallbladder mucosa. The neural nature of these components was confirmed by immunohistochemical labelling with antibodies specific for synaptophysin, glial fibrillary acidic protein, S100 protein and neurofilaments. Based on these findings, the lesion was diagnosed as ganglioneuromatosis. Reports of ganglioneuromatosis in animals have so far been restricted to the intestine. This is the first case of ganglioneuromatosis affecting the gallbladder in an animal in which no intestinal involvement was apparent.

Immunohistochemical expression of MDR1-Pgp 170 in canine cutaneous and oral melanomas: pattern of expression and association with tumour location and phenotype.

Canine melanoma (CMM) more commonly affects the oral mucosa and the cutis. CMM shares several features with human melanomas (HMM), included resistance to a broad variety of antineoplastic chemotherapy agents. P-glycoprotein 1 (Pgp) expression is a well-recognized feature of multi-drug resistance and the purpose of this study was to investigate its expression in treatment naïve CMM. We also investigated Pgp association with tumour location and histological features. Histology records of CMM were retrieved, including patients from 2012-2014. Twenty-five cases of CMM were included in this study. Results revealed that Pgp is expressed in CMM and oral tumours were more likely to have a membranous Pgp expression (100%) than cutaneous tumours (66.6%) (P = 0.010). Cytoplasmic and nuclear Pgp expression could also be identified. Results of this study bring useful data that help in understanding one of the possible mechanisms responsible of intrinsic chemotherapy resistance in canine CMM.

Cutaneous Heterotopic Brain Tissue (Neuroglial Choristoma) with Dysplastic Features in a Kitten.

A 3-month-old, male European shorthair kitten exhibited an ill-defined, soft mass on the skin of the frontal head, which was present since birth. The surgically resected tissue was representative of a discrete dermal and subcutaneous mass comprising islands of neurons, glial and meningothelial elements, sometimes atypical or dysplastic, separated by dense collagenous connective tissue. There was no evident connection between this tissue and the brain. Immunohistochemical examination confirmed the presence of neurons and a pleocellular glial population, supporting a diagnosis of cutaneous neuroglial choristoma believed to be secondary to sequestered (resolved) meningoencephalocoele. Ectopic brain tissue is very rare in small animals. Some atypical features displayed by this tissue may be misdiagnosed as neoplasia. Communication between surgeon and pathologist to clarify the relationship of the lesion to surrounding structures is helpful to avoid misdiagnosis.

Cartilaginous Tumors of the Larynx and Trachea in the Dog: Literature Review and 10 Additional Cases (1995-2014).

Cartilaginous tumors of the larynx and trachea are uncommon in the dog. The authors describe 10 cases diagnosed between 1995 and 2014 and review 16 cases in the literature. Seven of our cases were tracheal and 3 were laryngeal. Two of the laryngeal tumors were chondromas, which have not been previously reported in this site. The third laryngeal tumor was a myxochondroma. Of the 7 tracheal tumors, 6 arose from the ventral tracheal wall, including 2 that were extraluminal. Tracheal tumor types included chondrosarcoma (n = 3), chondroma (n = 2), and osteochondroma (n = 2). All of the laryngeal tumors and 5 of 7 of the tracheal tumors occurred in adult dogs (aged 5-11 years). The 2 tracheal osteochondromas were in young dogs (3-4 months) and were intrathoracic, while the remaining tracheal tumors were cervical. Surgical excision had a good outcome in most cases. Combining our 10 cases with the 16 previously reported cases showed that 6 (27%) of the affected dogs were Arctic breeds (Alaskan Malamute or Siberian Husky) suggesting a predisposition in this type of dog.

Naturally acquired visceral leishmaniosis in a captive Bennett's wallaby (Macropus rufogriseus rufogriseus).

A high prevalence of leishmaniosis has been reported from an increasing number of domestic and wild mammals around the world. In Australian macropods, Leishmania spp infection has been occasionally described in its cutaneous form only. The purpose of this report is to present a case of fatal visceral leishmaniosis in a captive Bennett's wallaby in Madrid, Spain, which was investigated by detailed macroscopic, histologic, and immunohistochemical examinations.

Intrapancreatic ectopic splenic tissue in dogs and cats.

Ectopic splenic tissue in the pancreas is a rare incidental finding in man that is often mistaken for pancreatic neoplasia. This condition is documented rarely in animals. This report describes the clinical and pathological features of four cases of intrapancreatic accessory spleens in dogs and cats. This is the first description of this lesion in the dog. The lesions comprised firm, well-demarcated, dark red, spherical masses that were composed microscopically of normal splenic tissue. The possible origin, differential diagnoses and potential practical significance of these lesions are discussed.

Reduced expression of E-cadherin and ß-catenin and high expression of basal cytokeratins in feline mammary carcinomas with regional metastasis.

Feline mammary carcinomas are highly aggressive neoplasms. Several mechanisms are thought to be involved in their progression, including the loss of epithelial adhesion molecules. The present study was carried out on 21 adenomas and 139 mammary carcinomas. Of the carcinomas, 66 were not reported to have metastasized, while the remaining 73 had evidence of regional lymph node metastasis at the moment of diagnosis. The relationship was examined between the expression of the E-cadherin-ß-catenin complex and basal (CK5/6, CK14) and luminal (CK8/18) cytokeratin expression. In the medical literature, carcinomas expressing basal cytokeratins are reported as having a poor prognosis in human breast cancer. Results revealed that preservation of the expression of E-cadherin and ß-catenin is a significant feature of carcinomas without metastasis, whereas carcinomas with metastasis reveal the loss of one or both adhesion molecules. Additionally, basal cytokeratin expression was statistically associated with the presence of regional metastasis. Furthermore, the expression of E-cadherin-ß-catenin was significantly correlated with the high expression of CK18 and low expression of CK5/6.

Intraepidermal glandular carcinoma of the nipple (mammary Paget-like disease) in 2 dogs.

Mammary Paget disease, characterized by diffuse infiltration of the nipple and areolar epidermis by carcinoma cells, develops in 1% to 3% of human mammary carcinomas. The purpose of this article is to present 2 cases of intraepidermal adenocarcinoma that resembled human mammary Paget disease, histologically and immunohistochemically, in dogs with underlying mammary carcinoma.

Histopathological lesions in 15 cats with leishmaniosis.

Recent research into the prevalence of Leishmania infantum infection in the Mediterranean basin points to the involvement of cats as a reservoir host, but only sporadic cases of feline leishmaniosis have been reported. Feline leishmaniosis presents primarily as cutaneous disease and diagnosis is based on the demonstration of the parasite by skin biopsy. The present report describes the microscopical changes in tissue biopsies from 15 cats with leishmaniosis. The biopsies were derived from the skin, ocular tissue and mucocutaneous junctions. The most common histopathological feature was diffuse granulomatous inflammation with macrophages containing numerous amastigotes. Other patterns included granulomatous perifolliculitis and lichenoid interface dermatitis, where there were fewer parasitized macrophages. The presence of amastigotes was confirmed by immunohistochemistry in each case. The results of the study confirm the value of histopathological and immunohistochemical techniques for the diagnosis of feline leishmaniosis.

Chondro-osteoblastic metaplasia in canine benign cutaneous lipomas.

Lipomas are common benign adipose tissue tumours in dogs. Variants of lipomas are characterized by an additional component (e.g. capillaries in angiolipomas or fibrous connective tissue in fibrolipomas). In human medicine, the presence of cartilage or bone within a lipoma is a rare event. Mechanical stress, tropic disturbances, contact with periosteum and other unknown factors may contribute to this transformation. The present report describes the clinical, gross and microscopical findings of four cases of chondrolipoma and two cases of osteolipoma in the canine skin. The possible histogenesis for these tumours in the dog is discussed.

Histopathological and immunophenotypical characterization of a combined melanoma and mucoepidermoid carcinoma in a dog / Simultaneous canine mucoepidermoid carcinoma and melanoma

The present paper reports the fi rst case of a canine high-grade (low differentiated) mucoepidermoid carcinoma,in which malignant proliferation of melanocytes has been detected. The tumoral mass was located in the lowerneck, pressing against the 7th cervical vertebral body in an aged dog of mixed breed. No macroscopic signsof skin or oral melanoma or carcinoma were detected elsewhere. The microscopic examination showed closeintermingling of the two components. Melanocytic proliferation rarely occurs accompanied by the colonizationof nonmelanocytic tumors, and the cause of such proliferation remains unclear. In human pathology, severalreports of pigmented mucoepidermoid carcinomas have been described, and in all cases the proliferationof the melanocytic component was considered as hyperplastic, and no sign of malignant proliferation wasdetected. However, neither in human nor in veterinary pathology has a case of intermingled melanoma andmucoepidermoid carcinoma been described(AU)

El presente trabajo describe el primer caso de un carcinoma mucoepidermoide canino pobremente diferenciadoen el que se ha observado una proliferación maligna de melanocitos. La masa tumoral se localizó a niveldel 7º cuerpo vertebral en perro de raza mestiza. No se detectaron otros signos macroscópicos de carcinoma y/o melanoma oral o epitelial. El examen microscópico reveló la proliferación conjunta de ambas subpoblaciones.La proliferación y colonización de melanocitos en tumores de origen no melánico es rara y no se conoce la causa.En Patología humana, se han descrito casos de carcinomas mucoepidermoides pigmentados, pero en todoslos casos se consideró la proliferación melanocítica como hiperplasia, no observándose en ningún caso signosde neoplasia. No existen en Patología humana ni veterinaria ningún caso descrito de carcinoma mucoepidermoideconcomitante con un melanoma maligno, siendo éste el primer caso descrito(AU)

Immunohistochemical characterization and evaluation of prognostic factors in canine oral melanomas with osteocartilaginous differentiation.

Melanomas are the most common malignant oral neoplasm in dogs. Osteocartilaginous differentiation in oral melanomas is a rare feature described both in veterinary and human medicine. Here, 10 cases of this type of neoplasm were used to study their immunohistochemical, biological, and clinical characteristics. Reactivity for S100 and melan A antigen was evaluated, and 4 prognosis factors (mitotic index, invasiveness of epithelium, nuclear atypia, and proliferation index) were analyzed and correlated with the clinical course of the neoplasms after diagnosis. Immunohistochemical analysis of the studied neoplasms, including the osteocartilaginous areas, showed positive immunoreaction for S100 and melan A, except in one dog, which was negative for melan A. Analysis of the results showed that oral melamonas with osteocartilaginous differentiation have a clinical course similar to that of other melanomas in the oral cavity. Analysis of the mitotic index and the expression of proliferation marker Ki-67 could be useful tools for predicting the biological behavior of these neoplasms.

Acute paraplegia associated with vasculitis in a dog with leishmaniasis.

A 14-month-old female crossbreed dog with leishmaniasis, receiving allopurinol, was presented with acute paraplegia. A diagnosis of renal failure with pelvic limb lower motor neuron signs was made and the dog was euthanased. Histopathological examination demonstrated leukocytoclastic vasculitis in multiple organs. Malacia and haemorrhage affecting the spinal cord was associated with multiple foci of vasculitis within the nervous tissue. Rupture and thrombosis of inflamed vessels caused haemorrhage in the spinal cord and subsequent paralysis.

Effect of selenium deficiency on the development of central nervous system lesions in murine listeriosis.

The effect of selenium (Se) deficiency, produced by feeding a Se-deficient diet, on the development of central nervous system (CNS) lesions was studied in mice infected with Listeria monocytogenes, administered in drinking water for 1 or 7 days in a daily dose of 10(9)organisms, or for 7 days in a daily dose of 10(7). Se-deficient mice differed from Se-normal controls in developing CNS lesions significantly more frequently. Moreover, regardless of Se status, mice receiving repeated doses of 10(9)organisms differed from those receiving a single 10(9)dose in showing CNS lesions at least twice as often. The majority of animals with CNS lesions showed an inflammatory pattern of rhombencephalitis (17/24), while only two of 24 showed choroiditis-ventriculitis-meningitis; five of 24 animals showed both inflammatory patterns. Listeria monocytogenes antigen was identified within the areas of inflammation by an immunoperoxidase technique. Neuritis of the trigeminal nerve was present in eight animals. The relative lack of pathological changes in the liver and spleen validates this murine model for the study of CNS listeriosis.

Repeated oral dosing with Listeria monocytogenes in mice as a model of central nervous system listeriosis in man.

Human listeriosis is a food-borne disease of immunosuppressed or previously healthy adults. The repeated oral administration of a sublethal dose (5x10(9)colony-forming units) of Listeria monocytogenes for 7 or 10 consecutive days led to the development of severe central nervous system (CNS) lesions in 25% of experimental mice. Histopathological examination of the brain revealed rhombencephalitis and ventriculitis as two distinct inflammatory patterns, resembling those seen in human listeriosis. This model would seem to be potentially useful for research on pathogenesis, predisposing factors and therapy in CNS listeriosis in man. 1999 W.B. Saunders and Company Ltd.

Penetration of Listeria monocytogenes in mice infected by the oral route.

In this study, it is suggested that the Peyer's patches are the most important point of entry of Listeria monocytogenes in the host after subclinical infection by the oral route. Microbiological, histopathological and ultrastructural evidence of infection was obtained in mice inoculated with a sublethal dose of 10(9) cfu. No mortality was observed. L. monocytogenes was isolated from the mesenteric lymph nodes from 6 hours post infection (hpi) through day 7 p.i. and from the liver and spleen from 24 h p.i. until days 5 and 7 p.i. respectively. Lesions were mainly restricted to the dome area of Peyer's patches and consisted of a purulent to pyogranulomatous inflammatory reaction. Scarce and minor lesions were also observed in the mesenteric lymph nodes and liver. L. monocytogenes was detected by immunohistochemistry in the Peyer's patches from 12 h p. i. to day 6 p.i. Ultrastructural study of Peyer's patches showed that the majority of Listeria cells were free within the cytoplasm of neutrophils and macrophages, not surrounded by a phagosomal membrane, and some of them were dividing.

Choroiditis and meningitis in experimental murine infection with Listeria monocytogenes.

In a study of central nervous system involvement in experimental listeriosis 27 Swiss CD1 mice were inoculated subcutaneously with Listeria monocytogenes. Systemic infection developed, as shown by the isolation of Listeria monocytogenes and histopathological lesions in the spleen and liver. In the central nervous system a mixed inflammatory infiltration in the ventricular system, especially in the choroid plexus, and leptomeningitis were the most relevant lesions. Inflammatory lesions were associated with the presence of Listeria monocytogenes, as demonstrated by a positive anti-Listeria monocytogenes immunoperoxidase reaction within phagocytic cells. It is suggested that choroiditis and meningitis developed as a consequence of hematogenous dissemination of Listeria monocytogenes within mononuclear phagocytes and penetration of these cells into the ventricular system through the choroid plexus.

The impact of a patient education programme in the control of hypertension.

The value of patient education programmes in the control of hypertension is controversial. We have conducted a prospective study to investigate a patient education programme in our clinic. Every new patient was randomised into one of two different groups: a control group (CG, n = 149) and an intervention group (IG, n = 138); the latter group was invited to attend two educational talks and subsequently one tutorial meeting. Blood pressure, heart rate, Quetelet Index, attendance, knowledge level, analytical parameters and the prevalence of other risk factors were measured in both groups before and after 6 months follow-up. No significant differences were detected between the two groups initially. At 6 months, both groups significantly lowered their BP; the only differences observed between groups (IG vs. CG) were: the number of correct answers to the questionnaire (14.5 +/- 3.7 vs. 12.9 +/- 3.7, P less than 0.01), the rate of occasional therapeutic abandonment (10.3 vs. 25%, P less than 0.05), 24 h sodium excretion (97 +/- 45 vs. 127 +/- 68 mmol/l, P less than 0.01) and the number of withdrawals (39 vs. 25%, P less than 0.05). We conclude that in spite of increased knowledge, less frequent abandonment of drug treatment and better observance of a low salt diet, patients in the IG had an increase in the number of drop-outs. Our data suggest that education in hypertension clinics should play a supportive role rather than a primary one in the control of high blood pressure.