Neurolymphomatosis caused by T-cell lymphosarcoma in a cat: imaging description and treatment review

Abstract

Case summary A 16-year-old domestic shorthair cat was evaluated for acute-onset right pelvic limb monoparesis localized to the sciatic nerve. MRI revealed a homogeneously contrast-enhancing, well-demarcated mass effacing the right sciatic nerve from its intravertebral origin to the end of the viewable field (mid-femur). Abdominal ultrasound revealed thickened small intestinal loops and enlarged mesenteric lymph nodes. Cytology of the small intestine was suggestive of lymphosarcoma. T-cell lymphosarcoma of the sciatic nerve and small intestines was confirmed with incisional biopsy. Treatment consisted of systemic chemotherapy with vincristine followed by the Wisconsin–Madison feline lymphosarcoma protocol, but despite treatment the patient neurologically worsened and was euthanized after 54 days. Relevance and novel information We present herein one of the first descriptions of neurolymphomatosis in the domestic cat that included post-intravenous contrast MRI. Treatment options based on recommendations for people with neurolymphomatosis include systemic chemotherapy, intrathecal chemotherapy and/or localized radiation chemotherapy. The authors recommend that all cats be screened for concurrent non-neuronal areas of lymphosarcoma before undergoing treatment for neurolymphomatosis, regardless of clinical signs.

Clinical and magnetic resonance imaging features of lymphoma involving the nervous system in cats

“… 1 , 4 However, in our study >50% of the cases showed spinal nerve infiltration, which was more common than previously reported. 8 , 11 , 12 Neurolymphomatosis in cats mainly has been reported as single case reports, 16 , 22 , 24 , 34 , 35 , 36 , 37 brachial plexus involvement being most common, 16 , 35 either with 8 , 12 , 21 or without 11 , 35 infiltration of the subarachnoid space and spinal parenchyma, and alone 35 or in association with other peripheral nerve involvement. 22 , 34 Although less commonly reported, 1 , 24 , 34 , 38 lumbosacral plexus neurolymphomatosis was the most common lesion pattern in our group of cats.…”

“… 8 , 11 , 12 Neurolymphomatosis in cats mainly has been reported as single case reports, 16 , 22 , 24 , 34 , 35 , 36 , 37 brachial plexus involvement being most common, 16 , 35 either with 8 , 12 , 21 or without 11 , 35 infiltration of the subarachnoid space and spinal parenchyma, and alone 35 or in association with other peripheral nerve involvement. 22 , 34 Although less commonly reported, 1 , 24 , 34 , 38 lumbosacral plexus neurolymphomatosis was the most common lesion pattern in our group of cats. Similar to a recent publication, 24 MRI findings in this group included symmetrical or asymmetrical thickening and enhancement of the lumbosacral nerve roots or femoral and sciatic nerves or both, meningeal enhancement of the conus medullaris, with or without the presence of an extradural, intradural, or intramedullary mass, or some combination of these.…”

“…Magnetic resonance imaging (MRI) is the imaging modality of choice to assess nervous system pathology, being a valuable noninvasive technique to reach reliable presumptive antemortem diagnoses. Despite increased availability of MRI in veterinary medicine, and the high incidence of nervous system lymphoma in cats, MRI features have been sparsely described in several case reports, 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 and in cases series including low numbers of cats. 2 , 6 , 26 , 27 Although the histopathologic distribution of nervous system lymphoma in cats recently has been described, 10 , 13 a description of specific MRI features in a larger cohort of affected cats is lacking.…”

Imaging and histopathologic features of reversible nerve root and peripheral nerve edema secondary to disc herniation in a cat

“…Common magnetic resonance imaging (MRI) features of PNST in cats and dogs include thickening of the nerve, with associated increased T2 and mildly decreased or unaltered T1 signal intensity 11,12 . These imaging characteristics are nonspecific and observed with other conditions including lymphoma and neuritis 13,14 …”

Focal Peripheral Neuropathy Associated with Lymphoma in Dogs

“…Outros quatro pacientes felinos com quadro clínico neurológico devido a infiltração dos nervos periféricos por linfócitos malignos confirmados apresentaram polineuropatia [18,20], mononeuropatia e lesão em nervos cranianos [24,38]. Todos, com imunofenotipagem conhecida para linfócito B. Ainda, há também descrição de pacientes com neurolinfomatose de linfócitos T como o caso de dois felinos em que um deles, foi evidenciado acometimento infiltrativo dessas células em nervo isquiático após apresentar monoparesia pélvica provavelmente secundária ao linfoma alimentar também confirmado por biópsia intestinal [2] e o outro, com monoplegia aguda e evolução para tetraplegia, além de paralisia mandibular como consequência da ação neurotrópica primária do linfoma, provocada também pelos linfócitos T neoplásicos [25]. Fato também relatado em paciente canino com claudicação progressiva em membro torácico direito, diagnosticado com neurolinfomatose de células T tanto em nervo radial quanto em plexo braquial [44].…”