Cerebellar cortical degeneration associated with feline leukemia virus infection and cerebellar lymphoma in a young cat

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

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.

Feline lymphoma of the nervous system. Immunophenotype and anatomical patterns in 24 cases

This study aimed to describe the specific localization and anatomical pattern of 24 feline lymphomas of the nervous system for which the immunophenotype was identified by immunohistochemistry investigations to support the potential specific correlation between subtypes and anatomical patterns. In total 10 tumors affected the spinal cord, eight the brain, four the peripheral nerves, one involved both the brain and the spinal cord, and one simultaneously the brain and the optic nerves. Twenty two tumors were primary lymphomas. The affected animals were 8 years of mean age. Tumors developed as an extra-axial mass (11 cases), intra-axial mass (six cases), leptomeningeal lymphomatosis (three cases), and neurolymphomatosis (five cases). One of them expressed both leptomeningeal lymphomatosis and neurolymphomatosis patterns. Two intra-axial brain lymphomas showed an angiotropic pattern. The optic chiasm was the most involved site for neurolymphomatosis. Immunolabeling was performed using anti-CD3, CD20, CD79a, PAX5, MUM-1, CD56, and anti-CD44 antibodies. In total, 12 tumors consisted of B cell lymphomas, and six of T cell lymphomas, two cases were double-reactive lymphomas while two cases consisted of non-B non-T lymphomas. B cell lymphoma affected animals of 6.4 years of mean age, while the T cell lymphoma affected older animals (mean age of 11.1 years). Extra-axial tumors mainly consisted of B cell lymphomas (8/11). Neurolymphomatosis expressed different immunophenotypes, and the B cell phenotype was the most prevalent in the optic chiasm. Two leptomeningeal lymphomatoses expressed T cell immunophenotype. For the first time, plasmacytoid differentiation was found for angiotropic lymphoma and neurolymphomatosis. All the cases, except one, were CD56-negative. CD44-expression confirmed a common malignant potential for all the anatomical patterns of the nervous system lymphoma in cats. Immunophenotype of feline lymphoma of the nervous system and its potential association with specific anatomical patterns should be strongly required in the diagnostic workup and clinical approach to this tumor especially when its primary origin is confirmed.

Allele and genotype frequencies of the SOD1 gene polymorphism associated with canine degenerative myelopathy in Belgian Malinois dogs in Greece

Background and Aim

Canine degenerative myelopathy (CDM) is an adult-onset fatal disorder associated with a point mutation of the superoxide dismutase 1 (SOD1) gene (SOD1:c.118G>A). This study aimed to determine the allele and genotype frequencies of this mutation in a group of Belgian Malinois dogs in Greece.

Materials and Methods

Samples (n=72) of whole blood were collected from 72 purebred dogs of the Hellenic Armed Forces; these samples were processed for DNA isolation, polymerase chain reaction, and digestion with the restriction endonuclease AcuI. Sample testing was conducted in compliance with ISO17025 accreditation requirements.

Results

The observed relative genotype frequencies were 71% for the homozygous (GG), 25% for the heterozygous (AG), and 4% for the homozygous mutant (AA) alleles. These frequencies were close to those expected, indicating no significant departure from Hardy-Weinberg equilibrium (HWE, p=0.395). The frequency of heterozygous animals indicates that a high risk of developing CDM in forthcoming generations exists in the tested population because mating among carriers would result in 25% AA progeny. The medical record of the group of study animals indicated selection against leishmaniosis, as applied throughout generations by owners and breeders. The potential association of this selection with the HWE status of the study population was discussed.

Conclusion

The SOD1:c.118G>A mutation was common in the tested group of dogs; thus, they are suitable for a follow-up investigation on the development and progression of CDM. A case-control study on animals with evidence of sensitivity to infectious myelopathy could provide new insights into disease pathogenesis.