Magnetic Resonance Imaging Findings in the Spine of Six Dogs Diagnosed With Lymphoma

Abstract

Lymphoma is one of the most common neoplasms in the dog. Despite its prevalence and the increasing use of advanced diagnostic imaging in veterinary patients only few reports of magnetic resonance imaging (MRI) findings in spinal lymphoma have been published to date. The purpose of this retrospective case series study was to describe the MRI findings in dogs with confirmed lymphoma affecting the spine and/or paraspinal soft tissues. Medical records were searched for patients that had MRI of the spine and a diagnosis of lymphoma during the period of 2005-2015. Data recorded from retrieved MRI studies were presence of focal or multifocal disease, structures involved, and signal characteristics on T2-W, short tau inversion recovery (STIR), and T1-W sequences prior to and following intravenous contrast medium administration. Six dogs met the inclusion criteria. Common findings included multifocal disease (4/6), vertebral involvement (5/6), spinal cord compression (4/6), and involvement of more than one spinal compartment (medullary cavity, vertebral canal, paraspinal soft tissues) (6/6). Vertebral changes were confined to the medullary cavity without evidence of cortical osteolysis. There was questionable involvement of the spinal cord in one case. All spinal and paraspinal lesions identified were T2-W isointense to hyperintense, STIR hyperintense, T1-W hypointense to isointense, and showed variable moderate to strong contrast enhancement. Additional lesions identified were enlarged intraabdominal lymph nodes, hepatomegaly, splenomegaly, and a splenic nodule. The STIR and T1-W postcontrast sequences were subjectively the most useful in identification of the spinal and paraspinal lesions.

Spinal extradural T‐cell lymphoma with paraneoplastic hypereosinophilia in a dog: clinicopathological features, treatment, and outcome

“…Thus, in dogs, lymphoma affecting the spinal cord most commonly manifests as a primary or metastatic extradural tumor. In many instances, there can be osseous involvement and, less frequently, extension to the paraspinal tissues [7][8][9][10][11][12][13]. Involvement of more than one spinal compartment (paraspinal tissues, vertebrae, and vertebral canal) has typically been observed in canine spinal lymphoma [9,11,12].…”

“…In many instances, there can be osseous involvement and, less frequently, extension to the paraspinal tissues [7][8][9][10][11][12][13]. Involvement of more than one spinal compartment (paraspinal tissues, vertebrae, and vertebral canal) has typically been observed in canine spinal lymphoma [9,11,12]. However, evidence of tumor tissue within the vertebral canal, resulting in spinal cord compression, with extension to the paraspinal tissues through the intervertebral foramina and no evidence of bone involvement, has only been reported in three dogs [10,12,13].…”

“…Involvement of more than one spinal compartment (paraspinal tissues, vertebrae, and vertebral canal) has typically been observed in canine spinal lymphoma [9,11,12]. However, evidence of tumor tissue within the vertebral canal, resulting in spinal cord compression, with extension to the paraspinal tissues through the intervertebral foramina and no evidence of bone involvement, has only been reported in three dogs [10,12,13]. A similar pattern (the presence of an epidural [extradural] mass with foraminal extension but without vertebral involvement) has been reported in people [14].…”

“…Reports of MRI findings in canine spinal lymphoma are scarce but, in most cases, lesions were hypo-to isointense on T1-weighted, iso-to hyperintense on T2weighted, and hyperintense on STIR images with moderate to strong contrast enhancement [10][11][12]. However, there is variability in the MRI signal characteristics in the cases reported in the literature and in three dogs, the lesions were hyperintense on precontrast T1-weighted images [8,13].…”

Clinical response to a lomustine/cytarabine-based chemotherapy protocol in a case of canine large granular lymphocyte T-cell lymphoma with spinal involvement

“…Other case reports provide additional information on the location and immunohistochemistry (IHC) of the lesions identified on necropsy, where the T-cell immunophenotype appeared to be more common in dogs with spinal lymphoma (Rosin, 1982;Dallman and Saunders, 1986;Ortega and Castillo-Alcala, 2010). Magnetic resonance imaging (MRI) features of lymphoma have been described in the literature (Palus et al, 2012;Allett and Hecht, 2016) and, although this technique may help in the diagnostic process, cytology or histopathology are usually required for confirmation. Cerebrospinal fluid (CSF) analysis may also provide a diagnosis by the identification of abnormal lymphocytes (Vandevelde and Spano, 1977).…”