Peripheral neuropathy in a cat with renal lymphoma.

A 12-year-old male cat was referred for progressive limb weakness lasting 2 weeks. Physical examination detected muscle atrophy and bilateral renomegaly with distortion of the renal contours. The cat was ambulatory but tetraparetic. It showed a peculiar posture on forelimbs with bilateral flexion of the carpi and extrarotation of forearms. The cat was unable to go upstairs or jump. Neurological examination showed findings compatible with peripheral nervous system involvement. Histopathological findings revealed a high grade non-B, non-T cell renal lymphoma and peripheral neuropathy characterised by demyelination, axonal degeneration and muscle denervation. In the absence of congenital, metabolic and infectious diseases or exposure to toxins, a paraneoplastic peripheral neuropathy was hypothesised. In humans and dogs, paraneoplastic peripheral neuropathies have been documented with different neoplastic processes including lymphoproliferative disorders. To the authors' knowledge, this is the first report of suspected paraneoplastic polyneuropathy in a cat with malignant tumour.