Spinal cord anaplastic meningioma with extra-neural metastasis in a cat

Abstract

ABSTRACT: Meningiomas are the most frequent neoplasms involving the brain in dogs and cats, and are occasionally observed in the spinal cord. They cause compression of the central nervous system; however, do not infiltrate the neuropile and rarely metastasize to other organs. The present study describes a case of anaplastic spinal meningioma with extra neural metastasis in a 20 years-old cat. Clinically, the feline presented a clinical history of 120 days with paresis of the hind limbs and loss of the tail’s movements, with subsequent death. At necropsy, there was an irregular and soft whitish mass involving the meninges from the lumbar intumescence to the sacral region of the spinal cord. Similar white nodular masses were observed in the lungs, liver and kidneys. Microscopically, both were composed of a poorly limited and infiltrative neoplastic proliferation composed by spindle, round and epithelioid cells, with a high cellular pleomorphism. On IHC, there was a severe immunostaining for vimentin and S100. Histopathologic and IHC analysis are important tools for definitive diagnosis of meningiomas in cats, and differentiation of other common neurologic disorders in these animals.