Magnetic resonance imaging and computed tomographic characteristics of a glioma causing calvarial erosion in a dog

Glioma with cribriform plate involvement in 6 dogs

Distinct patterns of local infiltration are a common feature of canine oligodendroglioma and astrocytoma, and typically involve the surrounding neuroparenchyma, ventricles, or leptomeninges. Infiltration of adjacent extraneural sites is rare and has not been well documented in veterinary medicine. Here we describe 6 canine gliomas with cribriform plate involvement (compression or infiltration) and caudal nasal invasion confirmed by neuroimaging, autopsy, and/or histology. All affected dogs were adults (9-12-y-old), and 3 were brachycephalic. Clinical signs were associated with the brain tumor, with no respiratory signs reported. Magnetic resonance imaging in 2 patients revealed a rostral intraparenchymal telencephalic mass with extension into the cribriform plate. All dogs were euthanized. Gross changes consisted of poorly demarcated, white or pale-yellow, soft, and, in oligodendrogliomas, gelatinous, intraparenchymal masses that expanded the rostral portions of the telencephalon and adhered firmly to the ethmoid bone and cribriform plate. Gliomas were classified as high-grade oligodendrogliomas (4 cases) and high-grade astrocytomas (2 cases) based on histology and immunohistochemistry for OLIG2 and GFAP. In all cases, there was evidence of cribriform plate invasion and, in one case, additional invasion of the caudal nasal cavity.

Anaplastic oligodendroglioma with nasal invasion and systemic metastasis in a dog

An 11-year-old spayed female French bulldog was referred on suspicion of nasal tumor. Anaplastic oligodendroglioma in the olfactory bulb that was suspected to have invaded the nasal cavity was diagnosed from imaging and histopathology. Metastasis to cervical lymph nodes was suspected, with no other metastases identified. The brain-to-nasal lesion and lymph nodes were treated with hypo-fractionated radiation therapy. Nasal congestion soon resolved. About 3 months later, follow-up computed tomography revealed multiple hepatic and splenic masses, which were cytologically suspected as metastatic oligodendroglioma. Nimustine, followed by toceranib phosphate, seemed to have no effect, and the dog died on day 167. Postmortem examination revealed the primary tumor disappearance and systemic metastases. Canine oligodendroglioma can grow outside the cranial vault, and systemically metastasize.

Systemic cellular viroimmunotherapy for canine high-grade gliomas

BACKGROUND

Oncolytic viruses constitute a growing field of interest, both in human and veterinary oncology, given that they are particularly helpful for treating non-surgical tumors and disseminated cancer, such as high-grade gliomas. Companion dogs present malignant gliomas with biological, genetic, phenotypic, immunological, and clinical similarities to human gliomas. These features favor comparative approaches, leading to the treatment of canine oncological patients to achieve translational applications to the human clinic. The systemic administration of oncolytic viruses presents a challenge due to their limitations in effectively targeting tumors and metastases. Therefore, the aim of this study is to evaluate the safety and antitumor activity of a virotherapy used in spontaneous canine tumors.

METHODS

Ten dogs with high-grade rostrotentorial gliomas underwent weekly systemic endovenous cellular virotherapy with dCelyvir (canine mesenchymal stem cells infected with the canine oncolytic adenovirus ICOCAV17) for 8 weeks. Efficacy was determined in seven dogs according to the Response Assessment in Veterinary Neuro-Oncology criteria considering clinical status and MRI measurements. Medical history, physical and neurological examinations, and vaccination status were evaluated prior to and during follow-up. Safety was evaluated by physical examinations and hematological and biochemical changes in peripheral blood. Immune populations were analyzed by flow cytometry in peripheral blood and by gene expression and immunohistochemistry in the tumor microenvironment.

RESULTS

The treatment was well tolerated and major adverse effects were not observed. Two dogs had partial responses (76% and 86% reduction in tumor size), and 3/7 showed stable disease. ICOCAV17 was detected in peripheral blood in nine dogs, and a correlation between the ICOCAV17 particles and anti-canine adenovirus (CAV) antibodies was observed. ICOCAV17 was detected in 3/9 tumor tissues after necropsies. Regarding tumor-infiltrating lymphocytes, the dogs with disease stabilization and partial response tended to have reduced memory B-cell infiltration and increased monocyte/macrophage lineage cells.

CONCLUSIONS

These findings indicate that dCelyvir is safe and presents efficacy in canine rostrotentorial high-grade gliomas. These data are relevant to the ongoing phase Ib regulated human clinical trial that is administering this virotherapy to children, adolescents, and young adults with diffuse pontine glioma. Celyvir should be further explored as a treatment in veterinary and human neuro-oncology.

Case report: Presumptive subcutaneous malignant peripheral nerve sheath tumor with intracranial invasion and osteolysis in the posterior fossa of a dog

A 13-year-old castrated male Toy Poodle presented with an acute vestibular disorder. Magnetic resonance imaging and computed tomography revealed a large oval space-occupying mass with skull destruction located from the subcutaneous tissue to the posterior fossa region. Histopathologically, the mass was a bundled growth of spindle-shaped mesenchymal tumor cells between the myofibrillar and collagen bundles. The cells were moderately irregular in size and had eosinophilic stained cytoplasm. The cells were highly atypical and had rare mitotic figures. Neoplastic cells were immunoreactive for S100, GFAP, Olig-2, SOX10 and immunonegative for NF, E-cadherin, and Claudin-1. Collective findings were presumptive with a diagnosis of malignant peripheral nerve sheath tumor.

Cerebral meningioma associated with extensive calvarium osteolysis and presumed intratumoral carcinoma metastasis in a cat

Case summary

A 10-year-old male neutered domestic shorthair cat presented with a 3-month history of weight loss, dysorexia and lethargy. Neurological examination revealed decreased mentation, absent menace response bilaterally and proprioceptive deficits affecting all four limbs; these findings were consistent with a forebrain disorder. Brain CT revealed an extensive asymmetric permeative osteolysis destroying two-thirds of the circumference of the calvarium and involving the right frontal, parietal, temporal and occipital bones, as well as the left parietal bone. This extensive bone lysis was associated with a large ‘plaque-like’ extra-axial subdural/pachymeningeal lesion extending within the soft tissues surrounding the calvarium. The cat was humanely euthanased. Post-mortem MRI was performed, which revealed a T2-weighted (T2W) hypointense subdural lesion and a T2W hyperintense circumferential extracranial lesion lining the right calvarium and left parietal bone. Histopathological analysis on a post-mortem sample of the lesion revealed a fibroblastic subtype of meningioma. Epithelial neoplastic cells were observed scattered through the meningioma, calvarium and surrounding muscular tissues, corresponding with presumed metastatic carcinoma.

Relevance and novel information

To our knowledge, this is the first report of an intracranial meningioma associated with such an extensive and diffuse calvarial osteolysis in veterinary medicine. This is also the first description of presumed metastatic inclusions (adenocarcinoma in this case) inside an intracranial feline meningioma, which is a rare phenomenon known as tumour-to-tumour metastasis in human medicine.

Clinical features, diagnosis, and survival analysis of dogs with glioma

BACKGROUND

Gliomas in dogs remain poorly understood.

OBJECTIVES

To characterize the clinicopathologic findings, diagnostic imaging features and survival of a large sample of dogs with glioma using the Comparative Brain Tumor Consortium diagnostic classification.

ANIMALS

Ninety-one dogs with histopathological diagnosis of glioma.

METHODS

Multicentric retrospective case series. Signalment, clinicopathologic findings, diagnostic imaging characteristics, treatment, and outcome were used. Tumors were reclassified according to the new canine glioma diagnostic scheme.

RESULTS

No associations were found between clinicopathologic findings or survival and tumor type or grade. However, definitive treatments provided significantly (P = .03) improved median survival time (84 days; 95% confidence interval [CI], 45-190) compared to palliative treatment (26 days; 95% CI, 11-54). On magnetic resonance imaging (MRI), oligodendrogliomas were associated with smooth margins and T1-weighted hypointensity compared to astrocytomas (odds ratio [OR], 42.5; 95% CI, 2.42-744.97; P = .04; OR, 45.5; 95% CI, 5.78-333.33; P < .001, respectively) and undefined gliomas (OR, 84; 95% CI, 3.43-999.99; P = .02; OR, 32.3; 95% CI, 2.51-500.00; P = .008, respectively) and were more commonly in contact with the ventricles than astrocytomas (OR, 7.47; 95% CI, 1.03-53.95; P = .049). Tumor spread to neighboring brain structures was associated with high-grade glioma (OR, 6.02; 95% CI, 1.06-34.48; P = .04).

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with gliomas have poor outcomes, but risk factors identified in survival analysis inform prognosis and the newly identified MRI characteristics could refine diagnosis of tumor type and grade.

B-Mode and Doppler Ultrasonography in a Murine Model of Ehrlich Solid Carcinoma With Different Growth Patterns

Ehrlich solid carcinoma (ESC) is one of the tumor models used in cancer research. Although it is widely used, it has no ultrasonographic descriptions. In this study, serial B-mode and Doppler ultrasonographic examinations were performed for 23 days for ESCs inoculated into 18 Swiss albino mice. The growth patterns were analyzed, and on the basis of their growth curve, the tumors were classified into two groups: fast growth (FG) and slow growth (SG). Ultrasonographic characteristics of the tumor’s capsule, margins, echogenicity, echotexture, vascular index (VI), distribution of vascular flow, and Doppler indices such as the resistive index, pulsatility index, and peak systolic velocity (SV) were analyzed and compared between the two groups. A high VI and earlier blood flow were noted in the FG group (p<0.05). Additionally, SV was higher in the FG group than in the SG group (13.28 ± 0.38 cm/s vs. 8.43 ± 0.26 cm/s). In contrast, a change in echogenicity and flow distribution patterns were observed, especially in FG tumors. Therefore, ESC presented with few ultrasonographic differences between FG and SG tumors, especially vascularization during the initial stages of tumor growth.

Cranial solitary osseous plasmacytoma and subjacent amyloid deposition in a dog

Solitary osseous plasmacytomas affecting the vertebrae, the zygomatic arch, and ribs occur in dogs. In this report, we describe clinical and imaging features of a solitary osseous plasmacytoma affecting the skull with deposition of amyloid forming a mass-like lesion. To the authors' knowledge, no similar cases have been reported before.

Canine Primary Intracranial Cancer: A Clinicopathologic and Comparative Review of Glioma, Meningioma, and Choroid Plexus Tumors

In the dog, primary intracranial neoplasia represents ~2-5% of all cancers and is especially common in certain breeds including English and French bulldogs and Boxers. The most common types of primary intracranial cancer in the dog are meningioma, glioma, and choroid plexus tumors, generally occurring in middle aged to older dogs. Much work has recently been done to understand the characteristic imaging and clinicopathologic features of these tumors. The gross and histologic landscape of these tumors in the dog compare favorably to their human counterparts with many similarities noted in histologic patterns, subtype, and grades. Data informing the underlying molecular abnormalities in the canine tumors have only begun to be unraveled, but reveal similar pathways are mutated between canine and human primary intracranial neoplasia. This review will provide an overview of the clinicopathologic features of the three most common forms of primary intracranial cancer in the dog, delve into the comparative aspects between the dog and human neoplasms, and provide an introduction to current standard of care while also highlighting novel, experimental treatments that may help bridge the gap between canine and human cancer therapies.