Vascular hamartomas of the liver of cattle

Solitary Biliary Hamartoma with Cholelithiasis in a Domestic Rabbit (Oryctolagus cuniculus)

Hamartomas of the liver and biliary system are extremely rare entities in both animals and humans. Biliary hamartomas in humans are usually multiple and constitute the von Meyenburg complexes. This report describes the presence of a large solitary mass arising from the edge of the right medial liver lobe of a domestic rabbit. Histologically, the mass was composed of an extensive network of large varying sized cystic structures lined by simple cuboidal to columnar epithelium within an abundant fibrous stroma. Within many of the cyst lumina were varying sized, pale white to greenish hard concretions identified as choleliths and were analyzed and found to be composed of calcium carbonate. This is the first known report of biliary hamartoma with cholelithiasis in rabbits.

Ultrasonographic findings in a cow with vascular hamartoma of the liver: case report

BACKGROUND

This is the first description of the ultrasonographic findings in a cow with vascular hamartoma of the liver.

CASE PRESENTATION

Ultrasonographic examination of a six-year-old Swiss Braunvieh cow revealed an excessive number of hypoechogenic blood vessels in the liver parenchyma and a thrombus in the right hepatic vein. The activities of the liver enzymes and the concentration of bilirubin were within the reference ranges. At postmortem examination, a poorly delineated, non-encapsulated lesion, measuring approximately 10 cm × 10 cm in diameter, was found in the right liver lobe. The cut surface of the lesion was sponge-like and contained extremely dilated blood vessels, one of which was occluded with a branching red thrombus. A vascular hamartoma of the liver with thrombosis was diagnosed based on the histological findings.

CONCLUSIONS

To our knowledge, this is the first description of the ultrasonographic findings of vascular hamartoma of the liver in a cow. Hamartoma should be considered part of the differential diagnosis in cows with an abnormally large number of blood vessels in the liver parenchyma. This case report broadens the spectrum of liver diseases and ultrasonographic findings of the liver in cattle.

A vascular hamartoma arising from the cervical spine of a cat

A 15-month-old cat presented for evaluation of worsening generalized proprioceptive ataxia. Computed tomography of the cervical spine revealed the presence of a compressive extradural bony mass involving the dorsal aspect of C1. Surgical exploration and debulking of the mass was performed. Histological evaluation of the mass revealed fibrovascular tissue consistent with a vascular hamartoma. This mass was deemed to be originating from the soft tissue associated with the C1 vertebra with subsequent bony proliferation. Surgical debulking of the mass resulted in complete resolution of clinical signs with no evidence of recurrence 2 years after surgery.

Fibroepithelial hamartoma in a domestic pig

This case report is the first description of a fibroepithelial hamartoma in a pig. The dysplasia, which covered half of the face of the newborn piglet, did not increase in relative size until the animal was euthanatized at 6 months of age. Histologic examination revealed a moderate orthokeratotic hyperkeratosis with variable degrees of epithelial proliferation. The main body of the dysplasia consisted of collagenous fibers. In addition, some proliferating small blood vessels as well as focally gathered dilated apocrine glands were evident. Given morphologic and clinical features, the diagnosis of a hamartoma seemed to be justified.

Cardiac Vascular Hamartoma in Two Slaughtered Cattle

Two cases of cardiac vascular hamartoma were detected in slaughtered cattle. In each case, a single nodular protrusion (ca 2.5 cm in diameter) was located in the same part of the right atrium. Tortuous vessels of variable size with irregular lumina were seen on the cut surface of each nodule. Microscopically, there were many dysplastic vascular structures within the nodules. The vascular structures showed various changes such as irregular thickening of the tunica intima and the tunica media, walls with variable amounts of fibres (elastic, collagen and smooth muscle), some of which were disarranged. Mature adipose tissue and fibrous connective tissue were seen close to the vascular structures and intervascular tissue. In the nodules, bundles of cardiac muscle were disorganized, intermingled with connective tissue, and in some areas embedded within fibrous connective tissue.

Congenital intrahepatic arteriovenous fistulae in a young beagle dog

Congenital intrahepatic arteriovenous fistulae, a rare hepatic vascular anomaly, in an 8-mo-old female beagle dog was investigated. The animal showed anorexia, repeated vomiting, hemorrhagic diarrhea, and jaundice for approximately 2 wk. There was mild to severe increase of serum alkaline phosphatase, glutamic-oxalacetic transaminase, glutamic pyruvic transaminase, total cholesterol, total bilirubin, and gamma-glutamyl transpeptidase. Macroscopically, the main abdominal organs showed hemorrhagic edema together with bloody ascites. Other characteristic findings were severe hepatic atrophy (right medial, quadrate, left medial, and lateral lobes) with multiple vascular cysts and compensatory hypertrophy of the other lobes. The cystic vessels seemed to extend from the proper hepatic arteries and their branches but were indistinguishable from the portal vein. Histopathologically, the atrophied hepatic lobes were characterized by wide, fibrous septa containing severe hyperplasia and anastomosis of the arteriolae and venulae and proliferation of bile ducts.