Meningioangiomatosis in Young Dogs: A Case Series and Literature Review

Abstract

Meningioangiomatosis (MA) is a proliferative disorder of the central nervous system (CNS) that has been reported rarely in humans and sporadically in dogs. Meningioangiomatosis may occur in the brainstem or cervical spinal cord of young dogs and can be identified tentatively by magnetic resonance imaging. The histopathologic hallmark of MA is a leptomeningeal plaque that extends along the CNS microvasculature and invades the adjacent neural parenchyma. This case series describes the neurologic signs, clinical progression, diagnostic imaging, and neuropathology of 4 dogs with MA. The 4 dogs with MA are compared and contrasted with 4 previously reported cases in dogs as well as with their human counterpart.

Imaging Diagnosis-Canine Meningioangiomatosis

“…9 MR imaging features of intracranial meningioangiomatosis in dogs include T1-hyperintensity or T1-isointen-sity, T2-hyperintensity, and strong contrast enhancement. 6,7 Our dog with the brainstem lesion differed due to the lack of homogenous contrast enhancement, with MR images most suggestive of an ill-defined inflammatory lesion rather than a mass lesion. The degree of contrast enhancement is likely to vary according to the degree of vascularity of the lesion.…”

“…2 There are eight reports of meningioangiomatosis in dogs. [3][4][5][6][7] The origin of meningioangiomatosis is not known. It has been classified by some as a hamartomatous proliferation of meningothelial cells, blood vessels and fibroblasts in variable proportions.…”

“…10 Similar to dog 2, most intracranial lesions of meningioangiomatosis are located in the brainstem, which is the proposed predilection site in dogs. 7 In Dog 1, the thoracic spinal cord was affected, demonstrating that lesions of meningioangiomatosis can affect both the intracranial and spinal components of the central nervous system. The MR imaging findings of meningioangiomatosis are variable.…”

Meningioangiomatosis associated with fibrous meningioma in a dog

“…Considering the eight previously reported canine cases and the case reported here, canine meningioangiomatosis, as with its human counterpart (Deb and others 2006), seems to affect preferentially young dogs and have a chronic progressive course. Thus, as indicated by Bishop and others (2004), meningioangiomatosis should be included in the differential diagnosis of juvenile to young dogs and rarely mature dogs with focal progressive brainstem or cervical spinal cord signs. Time to presentation in previously reported cases of meningioangiomatosis ranged from one month to two‐and‐a‐half years.…”

“…Eight cases of canine meningioangiomatosis have been reported in the veterinary literature. The cases in dogs involved the cerebral hemispheres and the brainstem (Stebbins and McGrath 1988, Ribas and others 1990, Pumarola and others 1996, Lorenzo and others 1998, Bishop and others 2004).…”