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

Large T-cell extradural lymphoma with concurrent marked cerebrospinal fluid eosinophilia in a dog

A 3-year-old male pit bull terrier was presented for a 4-day history of progressive tetraparesis and cervical pain. Magnetic resonance imaging confirmed an extradural mass within the left lateral vertebral canal extending from caudal C5 to mid-T2. Lumbar cerebrospinal fluid (CSF) demonstrated marked (90%) eosinophilic inflammation. A C6-7 dorsal laminectomy and C7-T2 left hemilaminectomy were done, with gross disease remaining. Histopathology revealed a large T cell lymphoma with marked eosinophilic infiltration. The dog underwent CHOP-based chemotherapy with resolution of clinical signs, with a similar course of therapy performed at recurrence 37 months after initial presentation. The dog was euthanized 39 months after presentation for multiorgan failure secondary to neutropenic sepsis and aspiration pneumonia. This represents a positive long-term response to multimodal treatment of extradural T-cell lymphoma within the vertebral canal associated with a marked CSF eosinophilia.

MRI characteristics of ventral vertebral venous plexus occlusion due to lymphoma in a large breed dog

Intravascular lymphoma is a rare presentation of lymphoma with a predilection to the central nervous system (CNS). A 9-year-old male-neutered Collie presented with a 3-month history of lymphadenopathy and a 6-day history of an acute onset, progressive, painful, symmetrical L4-S3 myelopathy. Magnetic resonance imaging revealed multifocal extradural spinal cord compressions from L3 to L6 secondary to a bilaterally enlarged and occluded ventral vertebral venous plexus (VVVP). Histopathology revealed low-grade lymphoma within the venous plexus in the lumbar vertebral column, tracheobronchial lymph nodes, and tonsils. Intravascular lymphoma should be considered a differential diagnosis for enlarged VVVP causing compression of the spinal cord.

Case Report: Diffuse Lumbar Hyperostosis Causing Vertebral Canal Stenosis in a Dog With Concurrent Multicentric T-Cell Lymphoma

A 4-year-old female spayed Bullmastiff-cross presented with a 24-h history of progressive paraparesis. Neurological examination was consistent with L4–S3 myelopathy. On magnetic resonance imaging (MRI), all vertebrae showed homogenously increased short tau inversion recovery (STIR) signal with strong contrast enhancement. The vertebral canal was concentrically narrowed along the length of the L5 vertebra secondary to bony proliferation of the vertebral pedicles, dorsal lamina, and vertebral body. Cytological analysis of the peripheral lymph nodes and subsequent flow cytometry was consistent with T-cell lymphoma. The dog was euthanised due to poor prognosis. Necropsy confirmed the presence of stage V multicentric T-cell lymphoma, as well as diffuse hyperostosis of the vertebral bodies. This is the first report of presumed paraneoplastic lumbar skeletal hyperostosis.

Magnetic Resonance Imaging Features of Extradural Spinal Neoplasia in 60 Dogs and Seven Cats

This retrospective study describes the MRI features of extradural spinal neoplasia in 60 dogs and seven cats to identify potential distinguishing features between tumor classes and individual tumor types within each class. In dogs, mesenchymal tumors were most common (48%), with undifferentiated sarcomas being the predominant tumor type. Round cell neoplasms were second most common (35%), with lymphoma and multiple myeloma/plasma cell tumor comprising the majority of cases. Only two benign tumors were identified. In cats, lymphoma was most common (5/7), with one case of mesenchymal neoplasia and one case of metastatic carcinoma. Despite some overlap, certain imaging features were able to help prioritize differential diagnoses. The combined features that predicted round cell neoplasia (84%) included the preservation of vertebral shape, homogeneous contrast enhancement, and lesion centering on bone. The combined features that predicted mesenchymal neoplasia (73%) included altered vertebral shape, heterogeneous contrast enhancement, and lesion centering on paraspinal soft tissues. Round cell neoplasms were more likely to have cortical sparing, preservation of overall shape, lesion centering on bone, small soft tissue tumor size, and homogeneous contrast enhancement. Both epithelial and mesenchymal neoplasms were more likely to have cortical lysis, a cavitary component to the soft tissue mass and medium to large soft tissue mass size. The findings of this study can aid in prioritizing differential diagnoses in cases of extradural spinal neoplasia in cats and dogs, which can impact case management, but tissue sampling remains the gold standard for definitive diagnosis.