Neuropathology of Central and Peripheral Nervous System Lymphoma in Dogs and Cats: A Study of 92 Cases and Review of the Literature

Abstract

The literature about nervous system lymphoma (NSL) in dogs and cats is fragmentary, based on a few case series and case reports with heterogeneous results. The aim of our study was to retrospectively analyze 45 cases of canine and 47 cases of feline NSL and compare our results with previously reported data, also providing an extensive literature review. Breed, age, gender, clinical signs, type, and neurolocalization were recorded for each case. The pathological patterns and phenotype were assessed by histopathology and immunohistochemistry. The occurrence of central and peripheral NSL was similar between the two species in both primary and secondary types. NSL occurred with a slightly higher prevalence in Labrador Retrievers, and spinal cord lymphoma (SCL) was associated with young age in cats. The most frequent locations were the forebrain in dogs and the thoracolumbar segment in cats. Primary central nervous system lymphoma (CNSL) in cats most frequently involved the forebrain meninges, particularly as a B-cell phenotype. Peripheral NSL mostly affected the sciatic nerve in dogs and had no preferred location in cats. Nine different pathological patterns were identified, with extradural as the most prevalent SCL pattern in both species. Finally, lymphomatosis cerebri was described for the first time in a dog.

Diagnosis of lymphoma based on magnetic resonance imaging, analysis of cerebrospinal fluid, intraocular fluid and fine‐needle aspirate of a uveal mass lesion in a dog

“…5 Infiltration of these compartments as well as the pituitary gland and choroid plexus was more com-mon with B-cell than T-cell lymphoma in a study of 37 dogs. 2,5 The same authors reported that in the studied dogs, 81% had involvement of more than one compartment. 5 Large granular lymphocytes are a subset of lymphocytes featuring intracytoplasmic azurophilic granules and are normally present in small quantities in peripheral blood.…”

“…2 The largest study to date includes data of CNS and PNS lymphoma from 92 dogs and cats. 2 In a recent study of 45 cases of central and PNS lymphoma in dogs, the majority of the lesions were located intracranially (49%), followed by spinal canal (31%) and PNS (20%). 2 In that study, ocular involvement was not mentioned in any of the included cases.…”

“…Both B-and T-cell lymphomas are represented fairly equally and only a small subset of non-B-cell non-T-cell lymphomas have been reported. 2 Primary CNS lymphoma is rare and is reported in approximately 3% of dogs with primary intracranial or spinal neoplasia. 4,5 Metastatic nervous system lymphoma most commonly affects the meningeal, perivascular, intraparenchymal and intravascular compartments.…”

“…In dogs, primary CNS lymphoma is rare and is reported to account for approximately 4% of all canine lymphomas 2,3 . It is more commonly seen as part of a multicentric disease 2 .…”

“…In dogs, primary CNS lymphoma is rare and is reported to account for approximately 4% of all canine lymphomas 2,3 . It is more commonly seen as part of a multicentric disease 2 . The largest study to date includes data of CNS and PNS lymphoma from 92 dogs and cats 2 .…”