Infiltrative Rectal Adenocarcinoma in a Dog

Background: Intestinal neoplasms are uncommon in dogs and adenocarcinoma is the main histological type found. This neoplasm presents slow growth and high capacity of causing metastasis. Histologically speaking, neoplasm cells can present solid, tubular, papillary arrangement and note amorphous extra-cellular material. Clinically observed tenesmus, diarrhea, dyskinesia, hematochezia, mane, protrusion of the anus, weight loss, anorexia. The occurrence and clinicopathological aspects of tumors in dogs’ gastrointestinal tract, the rectal segment, remains poorly understood. Accordingly, the aim of the present study is to report a case on infiltrative rectal adenocarcinoma diagnosed in a dog.Case: A 7-year-old male dog representative of the Fila Brasileiro breed was presented to the Veterinary Hospital of University Federal Rural of Amazonia, with history of hyperthermia, anorexia, apathy and tenesmus. Imaging examinations depicted prostatomegaly. Exploratory laparotomy was performed and showed the thickening and hardening of the rectum segment. The animal was subjected to euthanasia. Necroscopy showed increased rectal perimeter; the mucosa in its opening presented atypical cerebroid aspect and irregular surface, and areas dark red. The rectal segment depicted a thick wall of  white color, irregular limits covering the muscular and adjacent sub-mucosa. The peri-rectal adipose tissue presented poor delimitation with the rectum, multiple greyish and reddish areas. Increased prostate and iliac lymph, and multi node of regular limits in the lungs. The histology of the rectal tissue depicted epithelium with differentiated neoformation, composed of atypical cells; nuclear anisocytosis, anisocariasis and hyperchromasia placed in small islands, cords or tubular formation. Neoplasm growth was unorganized and of infiltrative character. Some areas presented mucosal pattern cells with Signal Ring morphologic. Multiple rectal blood vessels, regional lymph nodes and lungs had neoplasm growth similar to that observed in the intestine. Mucosa also presented ulceration areas and lymphoplasmacytic infiltrate. There was fibroplasia, lymphoplasmacytic points and bleeding in the serous, as well as in the peri-rectal fat tissue. The immunohistochemical technique showed immunostaining in cytokeratin and vimentin antibodies, and in marked epithelial cells and tumor stroma markings, respectively.Discussion: The intestinal tumor diagnosis in dogs is found by associating history, clinical signs, radiographic, ultrasound findings and necropsty. Only one data about the occurrence of rectal adenocarcinoma in Fila Brasileiro specimens. With regards to sex, results were similar to those record, whose males presented higher prevalence of primary rectal tumors. The macroscopic characteristic is consistent with infiltrative neoplasms; thickening was related to the presence of the tumor. The histopathological findings evidenced growing infiltrative neoplasm formed by atypical cells of tubular arrangement. Microscopy featured a chronic ulcerative colitis frame, such alteration represents one of the main risk factors for colon rectal cancer in humans. Epithelial histogenesis was confirmed through immunohistochemical results that have revealed co-expression of the cytokine epithelial marker in most tumor cells. The vimentin mesenchymal marker in the neoplasm stroma was positive, fact that can be explained by occasional immune-reaction in the anti-bodies (cytokine and vimentin) and in non-differentiated carcinomas. The prognostic was negative in the current report. Such outcome was attributed to the infiltrative character observed in the trans-operative period. Necropsy, as well as the histopathological and immunohistochemical exams, confirmed the infiltrative rectal adenocarcinoma in the dog

Schistosomus reflexus in a Dog and a Cat

Background: Schistosomus reflexus (SR) is a congenital anomaly, that the animal presents exposed abdominal and thoracic organs. The alterations includes limbs malformation, abnormal spinal column, liver and diaphragm hypoplasia, genitourinary and gastrointestinal changes, on this way, the fetus can not survive. The aim of this study was to report the first SR case in dog and cat in Brazil, and describe anatomical, pathological and radiographic changes.Case: The puppy had ventral midline defect in the abdominal and thoracic wall extending from the sternum to the pubis with viscera exposition, including the heart, lung, liver, stomach, intestine, spleen, kidneys, moreover right army was abnormal, however no spinal column was present. It was performed radiography to evaluate bone abnormalities, and was diagnosed agenesis of carpal, metacarpal and phalange bones. The kitten had ventral midline defect measuring 4 x 2 cm, in the abdominal wall and exposition of liver, stomach, intestine and spleen, as well as tibiotarsal joint arthrogryposis on both lags. It was performed fetus radiography and no spinal column change was diagnosed.Discussion: Schistosomus reflexus is a congenital abnormality common in ruminants. Although it was few reported in dogs and cats. The two cases in this study are the firsts reposts in Brazil in these especies. In our case, the dog had exposition of abdominal and thoracic organs and died one hour after born, similar to this, another author reported a case where the thoracic and abdominal evisceration and the puppy died ten minutes after born. However, in another case with abdominal evisceration only, the puppy survived for eight days. Probably it happened because respiratore function was not compromised. The kitten had abdominal opening only, in turn, other authors reported a case whose abdominal viscera exposition was by pelvic fissure, and another case, what presented thoracic and abdominal evisceration, like our dog case. Some authors affirm that this defect causes fetal dystocia on ruminants, because of the vertebral column abnormality, what promote passage difficult at born moment. On the other hand, dogs did not present these kind of changes and dystocia was not related to this pathology on cases in dogs and cats, however most of these authors performed cesarean because the female did not get normal born. As well as, on two cases in kitten were reported vertebral column abnormalities, what can be related to dystocia. Even no animal of our study present any vertebral column abnormality, other bone changes were found, like carpal, metacarpal and phalange agenesis on army of the dog and tibiotarsal joint arthrogryposis on both lags of the cat fetus. The others report in dogs did not found vertebral column or bone changes, but in cats it was observed vertebral column abnormalities and other changes, like arthrogryposis on four limbs, skull flattening, mandibular brachignathism, reduced ossification of the cranial vault bones, palatoschisis and unfused eyelids. SR etiology is not clearly known, it may be related with genetic, mechanic, endocrine, metabolic, nutrition and infectious factors. The moment of embryonic development, where these factors influence the changes is related with abnormality grade. Although, Chromosomic abnormalities, like chromatid and chromosome breaks, non-homologous pairing of chromosomes was shown. In this study the bitch did not present any metabolic, endocrine or nutritional change, on other hand the queen was submitted to exogenous hormonal treatment to avoid pregnancy, what may be related to SR development. SR is a rare abnormality in dog and cat, fetus radiographic, anatomical and pathological findings confirmed to being this congenital defect, and this are the first reports in Brazil in these species

Paraganglioma de corpo aórtico em cão

Background: Aortic body paragangliomas are uncommon neoplasms that develop mainly in aortic and carotid bodies. It has been supposed that genetic factors and chronic hypoxia may stimulate tumor development. The brachycephalic dog breeds, as Boxer, are most predisposed to present this neoplasm. The clinical symptomatology is related to tumor size and localization. Usually aortic body paraganglioma has benign biological behavior, when it is malignant, rarely promotes metastases. The aim of this study was to report a case of the aortic body paraganglioma as death cause in a dog.Case: A canine, 10-year-old, male, cross breed, presented clinical signs as anorexia, emesis, cough, dyspnea and exercise intolerance. After death the animal was examined at the Department of Veterinary Pathology at the Federal Rural University of Amazonia. On necropsy, no pericardial effusion was identified, however pleural and abdominal effusion was observed, volume like 1000 and 700 mL, respectively. The heart had a neoplasm near the left atrium, it measured 6.5 x 8.2 cm, had irregular surface, firm consistency, grayish color, and at the cut showed infiltration in the myocardium, as well as obstruction of the left atrial lumen and left ventricle concentric hypertrophy. No distant metastases were found. Microscopically, the tumor consisted of polyhedral morphology cells, eosinophilic cytoplasm, spherical and hyperchromatic nucleus. Cells were grouped into lobes separated by fibrovascular stroma, large cells (less uniform cells), low mitotic rate and myocardial infiltration. On immunohistochemical analysis anti-cytokeratin, anti-vimentin and anti-S-100 antibodies were used. Tumour cells stained was absent for anti-cytokeratin and anti-vimentin, but was anti-S-100 positive. A case of malignant aortic body paraganglioma grade II was diagnosed.Discussion: The reported case was diagnosed in cross breed dog. However, brachycephalic dog breeds, as Boxer, are more predisposed to develop this kind of tumor. The development of these tumors is related to the genetic factors and chronic hypoxia. It was suggested that the tumor origin on this case is related to genetic factors, because the animal had no respiratory diseases, he was not brachycephalic and lived in a low altitude city, what exclude the possibility to have been induced by chronic hypoxia imposed by low oxygen. The clinical symptomatology presented by the animal days before death was related to the localization and size of the tumor. The macroscopic findings were similar to those of other studies. And the histopathological findings of the report were indicative for the histological classification of malignant aortic body paraganglioma. On immunohistochemical analysis it was negative for anti-cytokeratin and anti-vimentin antibodies, however was positive for anti-S-100 antibody, thus differentiated from other tumors that may occur in this local and confirmed the diagnosis of malignant aortic body paraganglioma grade II. The dog died due to tumor-related causes, however some authors indicate de tumor as a necropsy finding. The findings made it possible to conclude that tumor was aortic body paraganglioma and that it promoted cardiorespiratory complications related to localization and infiltration, what was worsened by pleural effusion leading the animal to the cardiogenic shock that culminated with death. It shows the importance of including this tumor in the list of differential diagnoses of heart diseases in dogs

Multilobular Tumor of Bone in a Dog

Background: Multilobular tumor of bone (MTB) is a primary bone neoplasm, uncommon in dogs. This tumor was called of many names for a long time, as: chondroma rodens, multilobular osteochondrosarcoma, multilobular osteoma, multilobular chondroma, calcificating aponeurotic fibroma, although MTB was preferred chosen, because these other name could be correlated with humans’ tumors. This tumor is observed specially in skull bone, although it was reported in zygomatic arc, hard palate, axilla, spine and penis. Mostly happen in big breeds dogs, and middle to old age patients. Clinical signs depending of region and how aggressive the tumor is, usually are related to compression of any structure. The growth of MTB is frequently slow and progressive, locally invasive, occurring relapse after surgical revomal, although the tumor has low to moderate metastatic potential. The aim of this study is to report a case of MTB in a female dog and describe anatomopathological changes.Case: A female dog, mixed breed, 13 year-old, of middleweight was admitted in Pathology Department of College of Agricultural Sciences and Veterinary Medicine (FCAV-Unesp), Campus of Jaboticabal - SP, to be undergone to necropsy. The patient have never shown any epileptic crisis or neurologic signs. In macroscopic examination was found a mass in skull, which invaded the orbit and frontal sinus, but it was not invading brain cavity. The neoplasm had and irregular surface, firm consistent, color was white mixed to red areas, after cut it was granular and rough, and had some point mineralized areas. The lobs of lung had much firm masses, colored gray to white. In cytology it was observed fusiform to polyhedric isolated mesenchymal cells, moderated pleomorphic, basophilic cytoplasm, thin granulated nuclear chromatin, and visible nucleoli that was involved by eosinophilic extracellular matrix. The proposed diagnostic was bone sarcoma. Histopathological assessment showed mesenchymal neoplastic proliferation, and multilobular characteristic, the lobules had different sizes and was well organized, and they were separated by thin conjunctive septs. In the center of lobules, there was an “island” with mineralized or chondroitin bone matrix, in some of these islands there were osteoclast. The cells had moderated pleomorphism and low mitotic activity (three mitotic cells in ten high-power field). At least, it showed big necrosis areas and invasion of near tissue. In lung was observed metastatic areas, which had same histopathologic way of primary neoplasm in skull. That way, the histopathologic exam was similar to Multilobular tumor of bone grade II.Discussion: The MTB is an uncommon neoplasm, which assaults mostly skull bone in large breeds dogs and middle age of eight years old. This case accord to literature about breed size, age and local of tumor.  The clinical signs in this dog was related to region what it was growing and near structure compression. Besides that, the patient had lung metastasis, that is the principal metastatic sites according to literature. The Histopathologic exam showed the same characters of MTB, which was considered grade II according to literature. Despite MTB is an uncommon neoplasm in clinic of dogs and cats, the epidemiological knowns as age, breed and localization, anatomopathological changes, and histopathological exam allows to have a diagnosis, showing the importance of including this neoplasm in differential diagnosis of bone tumor in dogs.

Squamous Cell Carcinoma in Third Eyelid of Cat

Background: The third eyelid neoplasms are uncommon in cats. The squamous cell carcinoma are easily found in head and neck of same specie, although is unusual in eye region. The more commun localization is eyelid and eyeball, being 60 and 15%, respectively. It could bee diagnosed by citology, histopathology, imunohistochemistry and molecular biology. The surgery is more effective treatment, because the tumor can be totally removed and it must available surgical margin. The aim of this study was to report a case of squamous cell carcinoma in third eyelid of a cat and show how it was treated with radical surgery. Case: A 11-year-old spayed female domestic short-haired white and black colored cat was presented for evaluation at Maria Dias Teixeira Hospital of Amazonia Federal Rural University (UFRA), of an red ocular mass fast growth in the left eye for 2 months. Physical exam was within normal limits. The animal presented discomfort on the region, when it was manipulated. The mass was ulcerated and blood-tinged ocular discharge, had 3.3 x 2 cm, beginning on third eyelid and overlay all the eyeball. Blood was collated to make exams. Complete blood count and serum chemistry profiles were within normal ranges, but leukocytes were increased and it was treated with Amoxicillin (22 mg/kg). It was performed biopsy to histopathology and immunohistochemistry diagnose, and radiography and ultrasonography to found metastasis. Ocular tissues were fixed in 10% formalin and processed routinely for histological examination. Sections were stained with hematoxylin and eosin and diagnosed poorly differentiated Squamous cell carcinoma. Immunohistochemistry was performed using anti-cytokeratin 1:200, anti-vimentin 1:150 and anti-actin alpha smooth muscle 1:700 antibodies. The tumor cells were positive for cytokeratin and negative for vimentin. In tumor stroma was immunostaining of myofibroblasts by actina alpha smooth muscle. Because of malignment and infiltrative neoplasm, it was chosen to perform eye and eyelid enucleation. At post-operative evaluation no complication was found and in tem days, surgical wound was held. Seven months post-operative no neoplastic tissue had growth on local. Discussion: A retrospective study at Belem and some close cities, which took all neoplasms and classified, found only 1.5% of ocular neoplasms, and no one was in cats. Similarly occurred with another study, that 1.21% out of ocular masses, just 12.5% was diagnosed in cats, showing how uncommon is ocular neoplasm in cats. Including theses lesions, less of then are only in third eyelid. Ultraviolet radiation is the most related probably causes of squamous cell carcinoma. At Belem City ultravioleta radiation is very high, can bee 11 in some stations, in a scale of 0 to 14, the medial temperature is 27ºC. Another factor that could influence squamous cell carcionoma progress is skin color, animals’ wich skin is light have more probably to develop this neoplasm. On our case, close to eye, skin was dark, although the carcinoma was growth at third eyelid mucosa, a local that have no protection to ultraviolet radiation. Myofibroblasts observed in the tumor stroma are important in the invasion process of this tumor in humans. The treatment used in this case was radical surgery, with no other adjuvant, what is indicate for some authors. Another authors prefer exscind only third eyelid, but sometimes it is not possible, because this kind of neoplasm is very infiltrate. The localization and the nodular form of squamous cell carcinoma found in this study is uncommon, mainly in cats. Histopathological and immunohistochemical analysis were important for definitive diagnostic. The treatment by enucleation of eyeball and removing the eyelids was effective, without relapse in 7 months after surgery. Keywords: oncology, ophthalmology, ocular neoplasm, feline

Expression of matrix metalloproteinase-2 and metalloproteinase-9 in the skin of dogs with visceral leishmaniasis

International audienceThe skin is the first organ to be infected by the parasite in canine visceral leishmaniasis. The enzyme matrix metalloproteinase (MMP) acts towards degradation of the extracellular matrix (ECM) and modulation of the inflammatory response against many kinds of injuries. The aims of this study were to evaluate the expression of MMP-2 and MMP-9 through immunohistochemistry and zymography on the skin (muzzle, ears, and abdomen) of dogs that were naturally infected by Leishmania spp. and to compare these results with immunodetection of the parasite and with alterations to the dermal ECM. Picrosirius red staining was used to differentiate collagen types I and III in three regions of the skin. The parasite load, intensity of inflammation, and production of MMP-2 (latent) and MMP-9 (active and latent) were higher in the ear and muzzle regions. MMP-9 (active) predominated in the infected group of dogs and its production was significantly different to that of the control group. Macrophages, lymphocytes, and plasma cells predominated in the dermal inflammation and formed granulomas in association with degradation of mature collagen (type I) and with discrete deposition of young collagen (type III). This dermal change was more pronounced in dogs with high parasite load in the skin. Therefore, it was concluded that the greater parasite load and intensity of inflammation in the skin led consequently to increased degradation of mature collagen, caused by increased production of MMPs, particularly active MMP-9, in dogs with visceral leishmaniasis. This host response profile possibly favors systemic dissemination of the parasite

Extrahepatic Cholangiocarcinoma in an adult Black Howler Monkey (Primates: Atelidae)

Over the past years, the number of neoplasm cases reported in nonhuman primates have considerably increased, with hepatocellular tumors reported in several species. Here a case report of extrahepatic cholangiocarcinoma in an adult male Black Howler Monkey (Alouatta caraya) is presented. The animal, kept as pet, was admitted at Veterinary Hospital presented clinical signs of cholestasis. After unsuccessful drug treatment, the animal was submitted to a cholecystoduodenostomy. During the surgical procedure, the hepatobiliary system was meticulously observed. The liver showed no macroscopic alterations, however, there was a solid mass throughout the common bile duct. Biopsy specimens were collected from the bile duct mass, liver and gallbladder for histological and immunohistochemical evaluations. Histological examination of the liver showed diffuse accentuated vacuolization and necrosis, besides hemosiderin accumulation inside hepatocytes. In the portal region, there was an accentuated proliferation of biliary ducts, which presented replete with bilirubin. Discrete neutrophilic inflammatory infiltrate and fibrosis were also observed. The bile duct mass showed a cellular proliferation of epithelial origin, confirmed by immunohistochemical analysis. The arrangement, characteristics and growth pattern of these cells revealed a malignant neoplasm. Despite the success of the procedure, the animal died hours later. Cholangiocarcinomas generally present high mortality rates, since its late clinical presentation make the treatments ineffective due to its large extensions at the time of diagnosis. The owner did not allow the necropsy, therefore the presence of other neoplasms and important organ alterations, which may be aggravated the patient's clinical condition, were not confirmed

Multilobular Tumor of Bone in a Dog

Background: Multilobular tumor of bone (MTB) is a primary bone neoplasm, uncommon in dogs. This tumor was called of many names for a long time, as: chondroma rodens, multilobular osteochondrosarcoma, multilobular osteoma, multilobular chondroma, calcificating aponeurotic fibroma, although MTB was preferred chosen, because these other name could be correlated with humans’ tumors. This tumor is observed specially in skull bone, although it was reported in zygomatic arc, hard palate, axilla, spine and penis. Mostly happen in big breeds dogs, and middle to old age patients. Clinical signs depending of region and how aggressive the tumor is, usually are related to compression of any structure. The growth of MTB is frequently slow and progressive, locally invasive, occurring relapse after surgical revomal, although the tumor has low to moderate metastatic potential. The aim of this study is to report a case of MTB in a female dog and describe anatomopathological changes.Case: A female dog, mixed breed, 13 year-old, of middleweight was admitted in Pathology Department of College of Agricultural Sciences and Veterinary Medicine (FCAV-Unesp), Campus of Jaboticabal - SP, to be undergone to necropsy. The patient have never shown any epileptic crisis or neurologic signs. In macroscopic examination was found a mass in skull, which invaded the orbit and frontal sinus, but it was not invading brain cavity. The neoplasm had and irregular surface, firm consistent, color was white mixed to red areas, after cut it was granular and rough, and had some point mineralized areas. The lobs of lung had much firm masses, colored gray to white. In cytology it was observed fusiform to polyhedric isolated mesenchymal cells, moderated pleomorphic, basophilic cytoplasm, thin granulated nuclear chromatin, and visible nucleoli that was involved by eosinophilic extracellular matrix. The proposed diagnostic was bone sarcoma. Histopathological assessment showed mesenchymal neoplastic proliferation, and multilobular characteristic, the lobules had different sizes and was well organized, and they were separated by thin conjunctive septs. In the center of lobules, there was an “island” with mineralized or chondroitin bone matrix, in some of these islands there were osteoclast. The cells had moderated pleomorphism and low mitotic activity (three mitotic cells in ten high-power field). At least, it showed big necrosis areas and invasion of near tissue. In lung was observed metastatic areas, which had same histopathologic way of primary neoplasm in skull. That way, the histopathologic exam was similar to Multilobular tumor of bone grade II.Discussion: The MTB is an uncommon neoplasm, which assaults mostly skull bone in large breeds dogs and middle age of eight years old. This case accord to literature about breed size, age and local of tumor.  The clinical signs in this dog was related to region what it was growing and near structure compression. Besides that, the patient had lung metastasis, that is the principal metastatic sites according to literature. The Histopathologic exam showed the same characters of MTB, which was considered grade II according to literature. Despite MTB is an uncommon neoplasm in clinic of dogs and cats, the epidemiological knowns as age, breed and localization, anatomopathological changes, and histopathological exam allows to have a diagnosis, showing the importance of including this neoplasm in differential diagnosis of bone tumor in dogs.