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

Clinical efficacy and psychological influence of lateral rectus approach for treating pelvic fracture with lumbosacral plexus injury

BACKGROUND

The surgical treatment of pelvic fractures is challenging, particularly after lumbosacral plexus injuries. Such impairments affect a patient's physiological function and can cause significant mental health problems. In recent years, the new transrectus lateral approach has favorably treated pelvic fractures and possibly preserved patients' physiological and psychological conditions. Therefore, investigating its clinical efficacy for treating pelvic fractures plus lumbosacral plexus injuries is of great clinical significance.

AIM

To investigate the clinical effect of the transrectus lateral approach on pelvic fractures complicated by lumbosacral plexus injuries as well as anxiety and depression.

METHODS

Data of 136 patients with pelvic fractures complicated by lumbosacral plexus injuries treated by the transrectus lateral approach (January 2011 to May 2024) were retrospectively analyzed. The patients' general data were collected via questionnaire. The Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) were used to assess anxiety and depression, respectively. We adopted a numerical rating scale (NRS) to evaluate pain degree, the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality, and Medical Research Council (MRC) Scale for Muscle Strength to evaluate treatment efficacy and complications.

RESULTS

The 136 included patients (92 male, 44 female) were a mean 48.02 ± 15.72 years old. The mean SAS score was 66.36 ± 5.15 preoperatively vs 42.15 ± 4.36 postoperatively, while the mean SDS score was 65.61 ± 5.02 preoperatively vs 43.83 ± 4.54 postoperatively, showing statistically significant differences (P < 0.05). The mean NRS and PSQI scores were significantly lower pre- vs postoperatively (P < 0.05). Postoperatively, 67 patients with fresh pelvic fractures plus nerve injuries achieved an MRC of M5, 22 achieved an M1-M4, and four achieved an M0. Postoperative motor function improved by a mean 4.20 grades (scale, 0-5). Among the patients with old pelvic fractures and nerve injuries, 19 achieved an M5, 16 achieved an M1-M4, and eight achieved an M0. Motor function improved significantly by a mean 3.30 grades (scale, 0-5; P < 0.05). No serious postoperative complications occurred.

CONCLUSION

The transrectus lateral approach to treating pelvic fractures plus lumbosacral plexus injuries can safely alleviate anxiety and depression, relieve pain, improve sleep quality, reduce intraoperative blood loss, and improve postoperative recovery.

Neurological Recovery in 14 Cats With Epidural Lymphoma Treated With Chemotherapy

The purpose of this study was to evaluate the rate and timing of neurological recovery in cats with epidural lymphoma who were treated with chemotherapy. The study included cats with various degrees of neurological impairment, confirmed diagnosis of lymphoma and spinal cord involvement. At the start of treatment, of the 14 cats diagnosed with lymphoma, 14.3% (n = 2) had ambulatory paraparesis, 14.3% (n = 2) had non-ambulatory paraparesis, 7.1% (n = 1) paraplegia with deep nociception, 50% (n = 7) were paraplegic with absent deep nociception and 14.3% (n = 2) had non-ambulatory tetraparesis. The chemotherapy treatment given was COP in 10 cats, COP and CHOP in 2 cats and CHOP in 2 cats. The number of chemotherapy sessions needed for neurological recovery varied from 1 to 4, with a total of 1-13 sessions per cat. The rate of neurological recovery was satisfactory in 83.3% (10/12) of the cats. This study indicates that cats with epidural lymphoma treated with chemotherapy have an 83.3% likelihood of partial neurological recovery and a 50% chance of full neurological recovery within a period of 7-28 days, regardless of the level of neurological impairment.

Introduction and Summary of Diagnosis and Treatment of Brain Tumors in Dogs and Cats

Meningiomas are the most common tumor type in the brain in dogs and cats, and survival times are much higher for cats than dogs. Glioma is much more common in the dog, and median survival time is poor without definitive therapy. No recommendations currently exist for treatment of glioma in dogs, and there is ongoing research as the dog is a valid spontaneous model for the human equivalent disease. Other intracranial tumor types like lymphoma and histiocytic sarcoma do occur, though at a much lower frequency.

Isolation of Tumour-Derived Extracellular Vesicles From the Plasma of Dogs Affected by Intracranial Tumours Showing Heterologous and Cross-Species Tropism: A Pilot Study

Canine and human brain tumours exhibit similar incidence rates and prognoses. Recent studies have demonstrated that extracellular vesicles derived from human patients (PDEVs) can be loaded with contrast agents and exhibit tumour tropism in murine models. We showed in a previous study that gadolinium-labelled EVs derived from canine gliomas (cPDEVs) can selectively targets murine glioblastoma cells in animal models. As a further step, we investigated the potential heterologous and cross-species tumour tropism of cPDEVs with brain tumours. With the perspective of imminent clinical application as both markers and drug delivery tools, we have successfully established the isolation protocol for cPDEVs and confirmed the aseptic conditions of the procedure and therefore the sterility of the isolated EVs. To assess the functionality of cPDEVs as drug delivery tool, they were loaded with indocyanine green (ICG) and injected into murine models of cancer for in vivo fluorescence biodistribution studies. Biodistribution analysis in mice revealed that ICG-loaded cPDEVs injected into murine models of subcutaneous tumours accumulated exclusively in the neoplastic tissue, even when evaluated 24 h post-injection, thus showing the cross-species and heterologous selective tumour tropism of the nanoparticles. With these tests, we have established a safe protocol for isolating and loading autologous cPDEVs with various markers, thereby paving the way for the clinical testing phase. These significant findings suggest the potential use of cPDEVs as a theranostic tool in the management of canine brain tumours, with promising implications for translational medicine applications in the future.

A "gullwing sign" on magnetic resonance imaging of extradural spinal tumors in dogs and cats allows prioritization of round cell neoplasia

Extradural neoplasms are the most common spinal tumors in small animals. A bilobed appearance of ventral extradural spinal lesions ("gullwing sign") on MRI has been described with various conditions. The objective of this retrospective study was to determine if a "gullwing sign" is more common with certain types of extradural tumors. MRI studies of dogs and cats with extradural spinal neoplasms were reviewed for the presence of a "gullwing sign". Statistical analysis was performed to evaluate a possible relationship between tumor class and the presence of a "gullwing sign". Sixty-six cases were included (5 epithelial, 31 mesenchymal, 4 neuroendocrine, and 26 round cell tumors). A "gullwing sign" was identified in 12 of 66 cases (18.2%) and was significantly more common with round cell neoplasia than other tumor types (P < .001; OR = 28.6, 95% CI [3.4, 241.1]). This information may aid radiologists in prioritizing differential diagnoses for extradural tumors in small animals.

Quantitative MRI for brain lesion diagnosis in dogs and cats: A comprehensive overview

MRI is widely used for the detection and characterization of brain lesions. There is a growing interest in the potential benefits of quantitative MRI (qMRI) in veterinary brain lesion diagnosis. Yet, the use of data processing tools in the veterinary field is not as democratized as for the diagnosis of human brain pathologies. Several reviews have addressed the characterization of brain lesions in cats and dogs. None of them is specifically focused on quantitative MRI data processing techniques for the diagnosis of brain lesions in the veterinary field. This paper aims to provide an overview of the evolution of qMRI on cats and dogs both in the clinical and preclinical fields. We analyze the achievements in the field as well as the remaining challenges in the diffusion of data processing tools for veterinary brain lesions characterization.

Case report: Intracranial epidermoid cyst in a cat

A 9-year-old American Shorthair, castrated male, weighing 4.3 kg was presented to our hospital because of intermittent ataxia and tetraparesis for 6 weeks. On presentation, the cat was in a stupor and on recumbency, and had vertical nystagmus in both eyes. These clinical signs suggested a brainstem disorder. MRI showed a mass lesion in the caudal aspect of the fourth ventricle with hyperintensity on T2-weighted and FLAIR imaging, low-intensity on T1-weighted imaging, and enhanced margins on post-contrast T1-weighted imaging. The mass compressed the fourth ventricle, causing obstructive hydrocephalus. A second cystic lesion was found rostral to the cerebellum. After MRI, the cat experienced respiratory difficulties and the mass was removed by emergency craniectomy. Although the mass including the cyst wall was successfully removed, the cat was euthanized because spontaneous breathing did not return. The mass was histopathologically diagnosed as epidermoid cyst. A biopsy to the rostral cystic lesion had not been performed and therefore the etiology of this lesion remained unclear. This is the first case of feline intracranial epidermoid cyst in which MRI and surgical excision were performed. MRI findings were similar to those in humans and dogs, suggesting that imaging studies are useful in cats for the diagnosis of intercranial epidermoid cyst.

Spinal lymphoma in a goat

A 3-year-old Pygmy Wether was presented for chronic hindlimb paralysis. A neurological exam revealed nonambulatory paraplegia with absent deep pain nociception, lack of hindlimb withdrawal reflexes, and paraspinal pain on palpation with T3 to L3 neurolocalization. MRI of the lumbar spine revealed an extensive, dorsal to dorsolateral, severely compressive, heterogeneously contrast-enhancing extradural lesion of the lumbar spine with intervertebral foraminal extension into the surrounding paraspinal musculature. Vertebral bone marrow involvement was also noted in the L5 and L6 vertebrae. A diagnosis of lymphoma was obtained after cytological sampling. This is the first case report describing specific MRI findings (signal characteristics, enhancement pattern, and perilesional changes) in a goat with paraspinal lymphoma.

An Illustrated Scoping Review of the Magnetic Resonance Imaging Characteristics of Canine and Feline Brain Tumors

Magnetic resonance imaging (MRI) is used pervasively in veterinary practice for the antemortem diagnosis of intracranial tumors. Here, we provide an illustrated summary of the published MRI features of primary and secondary intracranial tumors of dogs and cats, following PRISMA scoping review guidelines. The PubMed and Web of Science databases were searched for relevant records, and input from stakeholders was solicited to select data for extraction. Sixty-seven studies of moderate to low-level evidence quality describing the MRI features of pathologically confirmed canine and feline brain tumors met inclusion criteria. Considerable variability in data inclusion and reporting, as well as low case numbers, prohibited comparative data analyses. Available data support a holistic MRI approach incorporating lesion number, location within the brain, shape, intrinsic signal appearances on multiparametric sequences, patterns of contrast enhancement, and associated secondary changes in the brain to prioritize differential imaging diagnoses, and often allows for accurate presumptive diagnosis of common intracranial tumors. Quantitative MRI techniques show promise for improving discrimination of neoplastic from non-neoplastic brain lesions, as well as differentiating brain tumor types and grades, but sample size limitations will likely remain a significant practical obstacle to the design of robustly powered radiomic studies. For many brain tumor variants, particularly in cats, there remains a need for standardized studies that correlate clinicopathologic and neuroimaging data.

Clinical features, MRI findings and outcome of a primary extranodal B-cell lymphoma affecting the tympanic bulla treated with chemotherapy alone

Case summary

A 2-year-old neutered female feline leukaemia virus (FeLV)-negative domestic shorthair cat was referred with an acute onset of vestibular signs. A clinical examination identified evidence of otitis externa of the right ear and enlargement of the right mandibular lymph node. MRI revealed predominantly T2 and FLAIR hyperintense and contrast-enhancing lesions affecting the right external ear canal, tympanic bulla and nasopharyngeal regions with intracranial extension. Cytology and culture and sensitivity samples collected from the middle ear via myringotomy revealed a population of intermediate to large lymphocytes consistent with lymphoma and mixed Staphylococcus chromogenes and Pasteurella species infection. PCR for antigen receptor rearrangements on the ear cytology was consistent with a B-cell rearrangement. A primary extranodal B-cell lymphoma affecting the tympanic bulla and other sites with secondary septic otitis media and interna was diagnosed. After the improvement of clinical conditions after corticosteroid, antibiotic and chemotherapy treatment, the cat was alive 22 months after diagnosis without recurrence of clinical signs.

Relevance and novel information

This is the first report of a primary extranodal B-cell lymphoma affecting the tympanic bulla with suspected involvement of the nasopharynx and cranial vault treated with chemotherapy alone in the veterinary literature. Although very rare, B-cell lymphoma should be included in the differentials for diseases affecting the inner and/or middle ear and extending intracranially in cats. Chemotherapy represents a non-invasive treatment modality with a survival of up to 22 months appearing possible.

Diagnostic value of cerebrospinal fluid analysis in epileptic cats with unremarkable brain MRI or hippocampal signal changes only

OBJECTIVES

Cerebrospinal fluid (CSF) analysis is used in the diagnostic investigation of cats with epileptic seizures. The aim of this retrospective study was to evaluate the diagnostic value of CSF analysis in cats with epileptic seizures that have unremarkable brain MRI or only hippocampal signal changes.

METHODS

Unremarkable brain MRI or MRI studies with signal alterations in the hippocampus only in cats with suspected epilepsy and CFS analysis performed at the Small Animal Internal Department or Diagnostic Imaging Department at Vetmeduni Vienna, Austria, between 2011 and 2017 were reviewed. Total nucleated cell count, total protein, blood contamination and cytology data from CSF analysis were evaluated.

RESULTS

In total, 87 cats were included. Seventy cats (80.5%) had unremarkable MRI, five (5.7%) had hippocampal signal changes with contrast enhancement and 12 (13.8%) had hippocampal signal changes without contrast enhancement. Overall, four cats (4.6%) had abnormalities on CSF analysis; all (100%) had an increased total nucleated cell count (22 cells/μl, 7 cells/μl, 6 cells/μl and 6 cells/μl, respectively), and no cat had increased total protein (100%), although in one cat total protein was not evaluated. Three of these cats had unremarkable MRI and one had hippocampal signal changes without contrast enhancement. The median duration of epileptic signs prior to the MRI study was 2 days.

CONCLUSIONS AND RELEVANCE

Our results show that, in our cohort of epileptic cats with unremarkable brain MRI or with hippocampal signal changes, CSF analysis was usually normal. This should be considered before performing a CSF tap.

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.

Clinical and magnetic resonance imaging features, and pathological findings of spinal lymphoma in 27 cats

This multicentric retrospective study describes the clinical and MRI features and pathological studies of spinal lymphoma in 27 cats. MRI characteristics and their possible correlations with histopathological findings were studied. The most frequent neurological signs were rapidly progressive paraparesis (62.9%) or paraplegia (22.2%). Bimodal age distribution was found with 40.7% of cats aged ≤2.5 years (63.6% of them FeLV positive), and 44.4% of cats aged ≥8 years (16.7% of them FeLV positive). Spinal lymphoma was generally presented on MRI as an ill-defined epidural focal lesion with moderate to severe spinal cord compression, expanding more than one vertebral body. MRI lesions were typically localized in the lumbar vertebral segment (p = 0.01), circumferential to the spinal cord (p = 0.04), hyperintense on T2-weighted sequences (p = 4.3e-06), and isointense on T1-weighted sequences (p = 8.9e-07). The degree and pattern of contrast enhancement were variable. Other morphological patterns included paravertebral masses with extension into the vertebral canal and lesions centered in the spinal nerve roots. Involvement of vertebrae and adjacent spinal soft tissues was present in 74% of cases when present vertebral involvement was characterized by cortical sparing. When follow-up MRI studies (n = 4) were performed after treatment new lesions of similar nature but different localizations and extension were observed. Confirmation of spinal lymphoma was performed by CSF analysis in 4/27 (14.8%) of cases, by FNA in 6/27 (22.2%) of cases, by surgical biopsy in 10/27 (37%) of cases, by FNA and surgical biopsy in 1/27 (3.7%) of cases, by CSF, FNA, surgical biopsy and postmorten examination in 1/27 (3.7%) of cases, and postmorten studies in 5/27 (18.5%) of cases. Antemortem diagnosis was achieved in 22/27 (81.5%) cats. The presence of necrosis in histopathological studies as an unfavorable prognostic indicator of survival was significantly more probable when lesions were not hyperintense on T2-weighted sequences (p = 0.017). Spinal lymphoma in cats is a complex entity with heterogeneous imaging and histopathological appearance. However, certain MRI features may support a tentative diagnosis, which in a group of cases can be confirmed when combined with the CSF findings. For the rest of the cases, tissue sampling assisted by imaging findings remains necessary for definitive diagnosis.

Case report: MRI findings with CNS blastomycosis in three domestic cats

Blastomycosis is a systemic mycotic infection caused by dimorphic fungi. The disease is rare in cats, and reports on imaging findings with central nervous system (CNS) involvement are limited. Magnetic resonance imaging (MRI) was performed antemortem in three feline patients. Imaging findings that may allow prioritization of intracranial blastomycosis over other differential diagnoses included focal or multifocal intra-axial mass lesions with dural contact, lesion hypointensity on T2-weighted images and diffusion-weighted imaging/apparent diffusion coefficient map (DWI/ADC), strong and homogeneous contrast enhancement of the lesion(s), concurrent meningeal enhancement, marked perilesional edema and mass-effect, and ocular abnormalities. One cat was managed successfully and had a recurrence of CNS blastomycosis more than 4.5 years after the initial diagnosis. Repeat MRI at that point revealed both new and persistent (chronic) abnormalities.