Vascular hamartoma in the tongue of a horse

Hamartoma is defined as a benign tumor-like nodule composed of an overgrowth of mature cells and tissues that normally occur in the affected part but with disorganization. Vascular hamartomas are defined as disorganized and excessive proliferations of vascular tissue. Most vascular hamartomas are present at birth or during early infancy and are considered developmental lesions rather than true neoplasms. Vascular hamartomas are rarely described in horses, and reports have been limited to the dorsal carpal region, the ovary, and the face. In this report, we describe a vascular hamartoma arising from the tongue of a 2-year-old Quarter Horse.     

Cerebral vascular hamartoma in a geriatric cat

An 11-year-old castrated male domestic medium hair cat was presented with neurological signs consistent with a right thalamocortical lesion. Computed tomography (CT) images revealed a heterogeneously, hyperattenuating, poorly contrast enhancing intra-axial mass within the right lateral ventricle. The histological diagnosis at post-mortem examination was vascular hamartoma with hemorrhage and necrosis. This is the first report of a vascular hamartoma affecting the thalamocortex in a geriatric cat. Also, this is the first time that CT images of a feline cerebral vascular hamartoma have been reported.     

Abdominal fluid from a dog

A 2-year-old intact female mixed-breed dog with a 1-month history of lethargy and anorexia was evaluated for abdominal distension and an abdominal mass. The dog's last heat cycle, her third, was 1 month prior to presentation, and no reproductive cycle abnormalities were noted at any time. Hematologic and serum biochemical abnormalities were consistent with hemorrhage and inflammation. Ultrasonographic examination confirmed a large midabdominal mass and a moderate amount of abdominal fluid. Cytologically, the fluid showed evidence of pyogranulomatous inflammation, hemorrhage, and mesothelial reactivity, as well as ciliated columnar cells and free cilia that were interpreted as likely of oviductal origin. The mass was removed surgically, and the histopathologic interpretation was oviductal hamartoma with marked stroma formation and acute hemorrhage. To the authors' knowledge, this is the first reported case of oviductal hamartoma in any species and the first reported case detailing the finding of ciliated columnar epithelial cells in the abdominal fluid of a dog. Ciliated columnar epithelial cells in abdominal fluid should be considered indicative of a likely underlying oviductal lesion.     

Surgical removal of an ependymoma from the third ventricle of a cat

A 10-year-old spayed domestic shorthaired cat was presented for behavioural changes, signs suggestive of visual deficits and aimless circling. Neuro-ophthalmological examination suggested the cat had central blindness. CT scans following administration of iohexol demonstrated a contrast-enhancing mass in the vicinity of the third ventricle resulting in obstructive hydrocephalus. Following rostral tentorial craniotomy and incision through the cerebral cortex, the third ventricle was approached via the dilated left lateral ventricle. An ependymoma was seen through a dorsocaudolateral incision into the third ventricle, and removed by gentle manipulation and suction. The cat recovered unremarkably, regaining normal vision and behaviour.     

A cerebral granular cell tumor in a cat

A cerebral granular cell tumor is described in a 6-year-old, short-haired, female cat. The tumor was observed above the corpus callosum and completely infiltrating the third ventricle. Histologic examination revealed that the tumor was characterized by large cells containing densely packed intracytoplasmic granules and expressed psammoma body-like patterns and cholesterinic degeneration. Immunohistochemical analysis revealed granular neoplastic cells that were diffusely and strongly vimentin-positive, while they did not express cytokeratins, lysozyme, and synaptophysin. Based on morphologic and immunohistochemical findings, the tumor under study was considered to be of meningeal origin arising directly from the meninges or from meningeal elements scattered in the tela choroidea of the third ventricle roof.     

Cerebral malacia in a mule with ependymoma

Ependymoma is a rare tumour of the central nervous system that can vary in anatomical location and produce a broad range of clinical signs. Sporadically described in dogs, cats, cattle and horses, this disease has never previously been reported in a mule. This report describes a case of a 12‐year‐old mule showing neurological signs, including blindness, dysphagia, incoordination, sternal recumbency, depression, apathy and emaciation. Because of the worsening health conditions, the animal was subjected to euthanasia for humane reasons. At necropsy, an area of malacia in the right subcortical region of the frontoparietal area of the cerebrum and an ovoid, firm, grey, 2.4 × 1.0 × 0.7 cm nodule in the right lateral ventricle was observed. Histopathology revealed that the nodule was a densely cellular mass with cells arranged in nests and cords, formations of pseudorosettes with perivascular deposition of fibrillar eosinophilic material and the presence of a few lymphocytes. The cells had rounded and moderately hyperchromatic nuclei, punctate chromatin, distinct nucleoli, and indistinct cytoplasmic margins. Based on the histopathological features, the nodule was diagnosed as an ependymoma, a tumour considered rare, but that may be included in the differential diagnosis for diseases with neurological signs.     

A case report of RccHanTM: WIST rat with multiple neoplastic and non-neoplastic proliferative lesions

It is extremely rare to have multiple spontaneous proliferative lesions in young adult rats. Here, we report the occurrence of different proliferative lesions in multiple tissues of a 7-week-old female rat in a 1-week repeated toxicity study. Grossly, multiple white patches and nodules in the bilateral kidneys, femoral and subcutaneous masses, and a nodule in the liver were observed. Renal lesions were diagnosed as renal mesenchymal tumors. One of the femoral subcutaneous masses was diagnosed as an adenolipoma consisting of mammary epithelial cells and mature adipocytes. The other femoral and abdominal subcutaneous masses were diagnosed as lipomas consisting of mature adipocytes. The liver nodule was diagnosed as non-regenerative hepatocellular hyperplasia, which was characterized by the proliferation of slightly hypertrophic hepatocytes. In the cauda equina, the growth of enlarged Schwann cells around the axon was observed, and this lesion was diagnosed as a neuroma.     

Retrograde intussusception of the descending colon secondary to multiple colonic hamartomas in a neonatal foal

A neonatal Thoroughbred filly presented with a 3-h history of abdominal pain and distention that failed to respond to medical treatment. Diagnostic evaluation, including abdominal ultrasound, barium enema and proctoscopy, was suggestive of atresia coli. Exploratory laparotomy revealed a pedunculated mass in the wall of the diaphragmatic flexure of the ascending colon. The mass, subsequently diagnosed as a hamartoma, was attached to a smaller hamartoma by a fibrous pedicle originating from the descending colon. The descending colon had intussuscepted retrograde into the ascending colon along the fibrous band. The filly was euthanised due to poor prognosis.     

A cardiac rhabdomyoma in a Guinea pig

A guinea pig (9-week-old) that had been placed in a control group for a pharmacological test was found to have a single nodule on the surface of the right ventricular wall. In a transverse section of the heart after fixation, a whitish mass was found that extended from the subendocardium to the subepicardium of the right ventricular wall. Histopathological examination revealed a spongy network consisting of vacuolated spaces in the myocardium of the right ventricle extending to the myocardium and subepicardium of the right atrium. The vacuolated space was PAS-positive. Immunohistochemical examinations revealed that the lesions contained striated fibers that were positive for anti-desmin and anti-myoglobin. Electron micrographs revealed the lesions resulting in affected striated muscle fibers and accumulations of many glycogen granules. Based on the findings, the lesions were diagnosed as a cardiac rhabdomyoma. This is the first report of application of immunohistochemical examinations to diagnosis of cardiac rhabdomyoma in the guinea pig.     

Fatal nonneurological EHV-1 infection in a yearling filly

A case of fatal nonneurological equine herpesvirus 1 (EHV-1) infection in a yearling filly is described. Gross lesions included extensive pulmonary edema, prominent laryngeal lymphoid follicles, and congestion and edema of the dorsal third ventricle choroid plexus. Histologically, there was vasculitis, hemorrhage, and edema in the lungs and dorsal third ventricle choroid plexus as well as mild intestinal crypt necrosis with occasional intranuclear inclusion bodies. The perivascular and vascular inflammatory infiltrates were comprised mainly of T lymphocytes and macrophages. EHV-1 antigen was identified within the nucleus and cytoplasm of endothelial cells, dendritic-like cells of the pharyngeal lymphoid follicles, pharyngeal glandular epithelium, crypt enterocytes, and monocytes. Attempted virus isolation was negative. Weak seroconversion for EHV-1 was observed. Herpesvirus-like particles were identified within pharyngeal endothelial cells by transmission electron microscopy. Polymerase chain reaction amplified 369 and 188 base-pair fragments specific for EHV-1. The scarcity of pathognomonic viral inclusions and lesions in this case suggests that this disease may not be recognized, particularly in situations when ancillary laboratory procedures are limited.     

Cardiac hamartoma in a young squirrel monkey who died suddenly

A case of cardiac hamartoma in a 2-month-old squirrel monkey is reported. The monkey showed a loss of appetite and died suddenly. Microscopically, an encapsulated nodular lesion was found at the right atrial wall. The lesion consisted of irregularly shaped, slender myocytes intermingled with a few fibroblasts and collagen fibers. Neither nuclear atypia nor inflammatory cell infiltrate was seen. The constituting cells had stratified striations in the cytoplasm and reacted immunohistochemically for desmin, indicating the nature of myocytes. Based on the above findings, a diagnosis of cardiac hamartoma was made. This is the first case of cardiac hamartoma in this species.     

Carcinocythemia: First report in a cat and literature review

A 6‐year‐old female neutered European Shorthair cat was presented with a 2‐day history of lethargy and hyporexia. On physical examination, the cat was slightly depressed and had a 2.5 cm nodule in the left 3^rd mammary gland. The hemogram revealed mild leukocytosis with mature neutrophilia and moderate thrombocytopenia. On blood smear evaluation, rare pleomorphic cells, possibly of epithelial origin, were observed mainly at the feathered edge. The animal died about 12 hours after presentation, and a necropsy was performed. On histopathology, the mammary nodule was diagnosed as a tubulopapillary adenocarcinoma with vascular invasion and widespread metastases. Immunocytochemical tests for cytokeratins (AE1/AE3) confirmed the epithelial phenotype of the neoplastic cells observed on the blood smear. The present report describes a feline mammary carcinoma with widespread metastases and the presence of malignant epithelial cells in the peripheral blood referred to as carcinocythemia. This condition has been previously described in people and dogs. To the author's knowledge, this is the first reported case of feline carcinocythemia. As in other species, the phenomenon was associated with a terminal phase of systemic malignancy.     

Ovarian vascular hamartoma in a cow

A 5-year-old Holstein cow was examined for a unilateral enlarged ovary. A clinical diagnosis of ovarian tumor was established before a histological diagnosis of ovarian vascular hamartoma was made. Ovarian vascular hamartoma has not been reported previously in a live animal.     

Eurasian otter (Lutra lutra), a definitive host for Dirofilaria immitis.

A mature male and a mature female Dirofilaria immitis were found in the right ventricle of the heart of a naturally infected 2-yr-old male Eurasian otter (Lutra lutra) that had died of severe lung congestion at a zoo in South Korea. Both developing embryos and microfilariae were present in the uterus of the female D. immitis. Although circulating microfilariae were not detected in blood or tissue, the Eurasian otter may serve as a definitive host for D. immitis.     

Unilateral concurrence of pyelocaliceal diverticula and intracapsular angiomyolipoma in the kidney of a cat.

A 7-month-old cat was examined for progressive abdominal distension. Radiography showed a fluid-containing cyst, which had subsequently ruptured as the result of a fall. Nephrectomy was performed, and examination revealed the coexistence of pyelocaliceal diverticula with a cystic intracapsular angiomyolipoma (mesenchymal hamartoma) in the left kidney. The diverticula were present on both cranial and caudal poles of the kidney and were lined by transitional epithelium. The hamartoma was characterized by the presence of multiple mesenchymal tissues, including thick-walled blood vessels, smooth muscle, and adipose tissue.     

Malignant transformation of a giant congenital pigmented nevus (hamartoma) in a dog

A male Golden Retriever was born with a large area of abnormal skin and hair on the distal pelvic limb. A tumour arose from the proximal margin of this area at 5 years of age. Histopathological examination of the abnormal area of skin revealed an area in which follicles were surrounded by nodular accumulations of densely packed round to spindle-shaped cells with fine granular intracytoplasmic melanin. Similar cells were present within the subcutaneous fat, and clusters of densely pigmented melanocytes were scattered within the basal epidermis, follicular epithelium, and dermis. A diagnosis of giant congenital pigmented nevus (hamartoma) was made. The tumour from the proximal end of this area was composed of densely packed, moderately pleomorphic, poorly differentiated and pigmented, spindle-shaped to epithelioid melanocytes, and was diagnosed as malignant melanoma. Metastasis of the malignant melanoma to the stifle and inguinal regions occurred within 6 months. To date, the authors are unaware of prior reports of a canine giant congenital pigmented nevus (hamartoma) with transformation to a malignant melanoma.     

闽清并殖对终末宿主的感染性试验及并殖吸虫对人体致病性分型的讨论

探讨闽清并殖对人体的致病性。将闽清并殖新鲜囊蚴多次分别感染猫科、犬科和啮齿科的家猫、家狗及大鼠、小鼠、豚鼠。结果 ,只在猫、狗粪便中检及虫卵并在肺脏检及成虫 ,而鼠类未获感染。结合对已知并殖吸虫宿主的选择性的分析 ,发现对猫狗感染而对鼠类不适宜的虫种通常对人体致病 ,相反 ,对鼠类适宜而猫狗不适宜的虫种对人体大多不致病或致病力较弱 ,表明闽清并殖可能类似斯氏并殖对人体引起游走性皮下结节的病变     

Linear arrector pili muscle hamartoma on the tail of a sphynx cat

Arrector pili muscle (APM) hamartoma is reported in humans and dogs. We describe a linear APM hamartoma in a sphynx cat. The lesion was characterized by multiple nodules distributed linearly along the tail, made of randomly arranged hypertrophic smooth muscles, the size of which tended to wax-and-wane during a one year follow-up.