Melanotic neurofibroma in a steer

A melanotic neurofibroma in a steer was investigated histologically, immunohistochemically and ultrastructurally. A very large tumor mass was located in the region of the head and right cheek. The tumor tissue consisted of an admixture of cells resembling Schwann cells and spindle-shaped cells, and they frequently contained melanin granules. Neoplastic Schwann cells were positive for S100 protein, with variation in intensity of staining, but most spindled cells were S100 negative. The tumor cells displayed ultrastructural features similar to those of Schwann cells or perineurial cells. The presence of melanosomes in varying stages of melanization in both cell types suggests that they have a common origin. This is a tumor of neural crest origin showing schwannian and perineurial differentiation, with ectopic production of melanin granules.     

Rectal ganglioneuroma in a dog

An 18-month-old, spayed female Australian terrier cross was presented with a 10-month history of chronic large bowel diarrhea. Ulceration and two proliferative masses in the rectum were seen on colonoscopy. Surgical resection was performed to remove the masses, and the dog recovered without complications related to surgery. Histopathology was consistent with the diagnosis of ganglioneuroma. The dog had no clinical signs of disease within three months of surgery and was completely normal 2.5 years after diagnosis. This is the first report providing follow-up and successful outcome of a ganglioneuroma in the gastrointestinal tract of a dog.     

Cardiac ganglioneuroma in a juvenile pig

A cardiac mass (3 × 5 × 3 cm) was detected at the base between the right auricular wall and right vena cava of a slaughtered 6-month-old female mixed-breed pig during a meat inspection. The tumor comprised infiltrative prominent interweaving fascicles of Schwann cells with Verocay bodies. Moreover, the ganglion cells were scattered or aggregated throughout the neoplastic tissue. The ganglion and Schwann cells had neither cellular atypism nor mitosis. On the basis of the bearing site as well as the morphological and immunohistochemical features, this is the first case of a cardiac ganglioneuroma in a pig.     

Necrobacillary bronchopneumonia in a steer.

A one and one-half year old steer killed in a slaughterhouse had necrobacillary fibrinous bronchopneumonia with abscessation. Histologically, there were variably sized areas of coagulation necrosis in the lungs, thrombosis of pulmonary lymphatics, and fibrin deposits in the bronchioli and adjacent alveoli. Fusobacterium necrophorum in pure culture was isolated from the lung.     

Bilateral 'gut-tie' in a recently castrated steer

Small intestinal obstruction caused by 2 fibrous bands was found in a steer. Distended small intestine was palpable per rectum. Each band was located bilaterally between the caudal abdominal wall and the pelvic inlet. The compromised portion of intestine was considered nonviable and the animal was euthanized.     

Neuronal ceroid-lipofuscinosis in a Holstein steer.

A young, partially blind Holstein steer was affected by mild cerebral atrophy. Formalin-fixed cerebral gray matter was diffusely yellow brown. Microscopically, there were eosinophilic, autofluorescent granules primarily in the cytoplasm of cerebral neurons. There was also extensive retinal atrophy with complete loss of the rod and cone layers. Ultrastructural examination of affected cerebral neurons revealed a mixture of granular osmiophilic and lamellar patterns in the cytoplasmic storage bodies. This suggests the existence of neuronal ceroid-lipofuscinosis in the Holstein breed.     

Encephalitis caused by a Sarcocystis-like organism in a steer

Sarcocystis spp can cause poor growth, anorexia, fever, anemia, muscular weakness, nervousness, abortion, and even death in cattle. Lesions in the CNS of cattle infected with Sarcocystis spp are microscopic and relatively minor, compared with those in other organs. We report extensive encephalitis in a steer attributable to a Sarcocystis-like organism.