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.     

Nasal vascular hamartoma in a Domestic Shorthair cat

A nasal mass in a Domestic Shorthair cat was causing facial deformity, sneezing and intermittent epistaxis. Biopsy samples obtained previously had been non-diagnostic. Computed tomography images revealed an irregular, contrast-enhancing mass occupying a large portion of the righthand side of the nasal cavity. Previously described criteria for malignancy were not present. A ventral surgical approach combined with temporary, ipsilateral, common carotid arterial occlusion provided excellent access for debulking the lesion and collecting samples for histopathology. A nasal vascular hamartoma was diagnosed and clinical signs resolved postoperatively. This is the first documentation of this abnormality in the cat. Hamartomatous abnormalities should be included on the list of differential diagnoses for feline nasal mass lesions. The prognosis for hamartomatous lesions postoperatively is good, in keeping with their limited propensity for growth after maturity.     

Cerebral vascular hamartoma with thrombosis in a dog

A cerebral vascular hamartoma was identified in the frontal lobe, striatum and thalamus of the right side of the brain of a male, 7-year-old Shih Tzu. Histologically, the lesion consisted of thin-walled vessels, which showed various sizes and occasionally contained fibrin thrombi. These vascular walls were composed of a single layer of fibromuscular tissue lined by flat endothelium with various amount of collagen, but devoid of large coat of smooth muscles and elastic tissue. Immunohistochemically, the lining endothelial cells were positive for von Willebrand Factor antibody. Neuropil between the vessels was stained with Klüver-Barrera stain, and positive for synaptophysin and GFAP antibodies. Based on these findings, the lesion was diagnosed as vascular hamartoma, which might resemble venous malformation in humans.     

Cerebellar vascular hamartoma in a British Shorthair cat

Cerebellar vascular hamartoma was diagnosed in a 16-month-old cat following magnetic resonance imaging and incisional biopsy. The clinical features were consistent with the cerebellar site of the lesion accompanied by signs attributable to cerebellar herniation through the foramen magnum and increased intra-cranial pressure. A lesion of this type represents a previously unreported differential diagnosis for central nervous system lesions in young cats.     

CSF from a puppy with a cerebral vascular hamartoma

A 9-week-old puppy with refractory seizures and a dome-shaped head presented to the Mississippi State College of Veterinary Medicine Specialty Center for suspected hydrocephalus. Computerized tomography (CT) findings included transtentorial herniation and an intra-axial mass with dystrophic mineralization. Cerebrospinal fluid analysis revealed an increased nucleated cell count of 1100/μl (RI < 5/μl), erythrocyte count of 2.2 × 10⁶/μl, and markedly increased microprotein of 1939 mg/dl (RI < 30 mg/dl). On cytologic examination of the CSF, numerous erythrophagocytic, and hemosiderin-laden macrophages were observed, which indicated chronic active hemorrhage. Many neutrophils, macrophages, and lymphocytes that contained numerous intracytoplasmic, pleomorphic, bright yellow crystals were observed. Considering the ongoing hemorrhage, the crystals were presumed to be hematoidin. A biopsy with histopathology was performed on the intra-axial mass, and the results were consistent with a vascular hamartoma. We speculate that the formation of these crystals was related to the ongoing hemorrhage associated with the vascular hamartoma. Identification of these crystals may be useful to aid in the identification of chronic hemorrhage associated with vascular malformations or lesions within the central nervous system.     

Surgical removal of a localised vascular hepatic hamartoma in a dog

A 2-year-old male Labrador Retriever was presented for sudden abdominal distension. Abdominal ultrasonography revealed abundant abdominal fluid and a hepatic mass, which was removed by total lobectomy. Histologic evaluation of the mass supported a vascular hepatic hamartoma. Vascular hamartomas are rare malformations in animals and only two cases have been reported in the dog. This is the first recorded case of a canine vascular hepatic hamartoma treated surgically and having a successful long-term outcome.     

A cardiac vascular hamartoma in a calf: Ultrasonographic and pathologic images

A right atrial mass was observed by ultrasound in a 3-month-old red Holstein calf. Differential diagnoses included endocarditis or tumor. Due to the poor prognosis, the calf was euthanized. On gross examination, there was a marked dilation of the right atrium. A round, poorly delineated, 2 cm mass was visualized in the right atrium. Microscopic findings were consistent with a vascular hamartoma.     

Cardiovascular images: vascular hamartoma of the mitral valve in a horse

An 8-month-old Hanoverian gelding was presented with a history of cardiac murmurs that were not apparent as a foal nor reported at the time of castration. Major echocardiographic findings included mitral valvular thickening, functional stenosis, and mitral regurgitation of sufficient severity to cause diastolic and systolic cardiac murmurs, left-sided volume overload, and pulmonary hypertension. Due to the hemodynamic severity of the lesion and poor prognosis for future performance and longevity, euthanasia was elected. On gross postmortem examination, there was focal fibrous epicarditis affecting the heart base, and the left atrium was moderately dilated. The mitral valve surface was irregular and contained several nodules along the atrial face of the cusp. Histologically, this lesion was diagnosed as a vascular hamartoma, which is rarely reported in veterinary species and has not been described in heart valves. This benign proliferative lesion, and concurrent valvular dysfunction, was associated with an unusual manifestation of clinically evident disease and should be differentiated from common incidental valvular lesions such as hematocysts.     

Hemangiosarcoma in a cow

A 4-year-old cow initially examined because of hindlimb lameness had a waxing and waning course of illness for 31 weeks. Signs included lameness, swelling of the affected limb, and intermittent fever, and anorexia. Radiography and bacterial culturing suggested osteomyelitis. Terminally, there was peracute anemia and dyspnea. The final diagnosis was hemangiosarcoma of the metatarsus, with metastasis to the lungs.     

Megaesophagus in a cow

Megaesophagus developed subsequent to presumed pharyngeal trauma in a cow. Signs resolved after prolonged antibiotic treatment and supportive care.     

Endocarditis in a cow

Bacterial endocarditis of the tricuspid valve was diagnosed in a cow with weight loss, reduced milk production, and intermittent fever. Clinical signs of disease included jugular and mammary vein pulses, tachycardia, large cardiac silhouette, and grade-III/V holosystolic murmur. The diagnosis was also supported by echocardiographic findings and isolation of Streptococcus viridans from blood samples. The cow was treated with penicillin, furosemide, acetylsalicylic acid, heparin, and potassium chloride and survived 14 months after the diagnosis, producing 1 live calf and 4 viable embryos. The cow's heart rate exceeded an upper normal limit of 80 beats/min during most of the initial 4 months of treatment. Additional clinical signs of disease that were observed during treatment included diarrhea, ventral edema, and coughing. General medicine and cardiology textbooks have previously minimized the potential benefits of anticoagulant use in cases of septic endocarditis. The advent of routinely performed embryo transfer procedures may make treatment of endocarditis feasible in cattle with exceptional genetic merit.