Congenital Intrahepatic Vascular Anomaly in a Clinically Normal Laboratory Beagle

Abstract

Routine necropsy examination of a clinically normal, ten-month-old male beagle dog identified disruption of the dorsal aspect of the right median liver lobe by a multiloculated, pale tan-white, thick-walled mass, with diffuse hypertrophy of the left and caudate liver lobes. The nature of the lesion was investigated using a variety of immunohistochemical and histochemical techniques. Histologically, the lesion was characterized by marked, focally extensive vascular hyperplasia and ectasia with lobular atrophy, periportal fibrosis, and biliary hyperplasia. The endothelium of proliferating vessels was positive for von Willebrands factor, and proliferating bile ducts were positive for pancytokeratin. Based on the gross and histologic appearance, this lesion was identified as a vascular hamartoma with arteriovenous fistula. It is important to note that this spontaneous lesion may occur in the laboratory beagle in the absence of clinical signs.

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

“…Similar thrombi were found in four of eight hamartomas in cattle [16]. The ascites seen in our patient was due to portal hypertension [21]. The ultrasonographic findings of the liver were uncharacteristic of cholestasis [25] or liver tumours [27].…”

Canine mesenchymal hamartoma of the eyelid

“…In the human literature, hamartomas are reported mainly in newborns and are usually present from birth, except in two reports of hamartomas in adults 26,27 . Interestingly, all dogs in this study, as well as those described in the veterinary literature, were middle‐aged and older dogs, ranging between 2 and 15 years of age 7–18 …”

“…Canine hamartomas have been described in dogs in several different tissues and organs, including kidney, lung, skin, periodontal ligament, vasculature, musculature, peripheral nerve, spinal cord, and hypothalamus 7–18 . Although canine hamartomas are reported in several different anatomic locations, the reports are mostly single case reports or sporadically descriptions of 3–5 patients.…”

Vascular Hamartoma in the Uterus of a Female Sprague-Dawley Rat with an Episode of Vaginal Bleeding

“…In addition, cavernous or sinusoidal structures were not associated with a-SMA-positive pericytes, and some vasculatures had discontinuous muscular walls. Heterogeneity of the vasculatures composing a lesion is observed in some vascular hamartomas (Sugiyama et al 2007;Yasuno et al 2011) or congenital vascular abnormalities (Booler 2008;Redondo 2007), but not in vascular tumors (Calonje and Flecher 2007). As per these histological features of the uterine vasculatures, the lesion in the present case might be a vascular malformation rather than a true neoplasia.…”