Neuroblastoma in the dog

Rosettes and pseudorosettes in veterinary neuropathology

Rosettes and pseudorosettes are morphologic cell arrangements found in many neuroepithelial neoplasms in human medicine, including embryonal nervous system tumors (neuroblastoma, medulloblastoma, pineoblastoma, and retinoblastoma), non-embryonal nervous system tumors (ependymoma, astrocytoma, oligodendroglioma, and choroid plexus tumors), and other extraneural neuroepithelial neoplasms. Although these structures are also described in neuroepithelial neoplasms of domestic animals, their frequency is still poorly characterized or inconsistently documented in veterinary medicine. Furthermore, rosettes and pseudorosettes need to be interpreted with caution and within a clinical and pathologic context and should not be solely relied upon for diagnostic confirmation of a particular neoplasm. Here, we review the morphologic features and frequency of the most common types of rosettes and pseudorosettes described in neuroepithelial neoplasms of domestic animals, focusing primarily on those occurring in the nervous system and closely associated tissues.

Features of a rare peripheral primitive neuroectodermal tumour arising from the thoracic spine in a juvenile canine patient

Peripheral primitive neuroectodermal tumours are rare tumours in juveniles. The current patient was a paraplegic 8‐month‐old Scottish deerhound with a suspected pulmonary mass. Radiographically, there was a large extrapleural mass within the mid‐left hemithorax. On MRI, the mass was mainly hyperintense on T2‐weighted images, isointense on T1‐weighted images and was heterogeneously strongly contrast enhancing with a multilobulated appearance, spinal cord compression, paraspinal musculature invasion and intrathoracic extension. Those changes were confirmed on post‐mortem, and the mass diagnosed based on immunohistochemistry.

Surgical Excision of an Adrenal Neuroblastoma in a Dog

A 11-month-old, intact male, Rhodesian Ridgeback was presented to the Veterinary Teaching Hospital with signs of inappetence, lethargy, and abdominal pain for 3 days. A large and well-defined abdominal retroperitoneal mass, related with the left kidney, at the expected location of the adrenal gland, was revealed by radiography, ultrasound, and computed tomography. The mass extended caudally to the iliac artery bifurcation, compressing the aorta, caudal vena cava, and both kidneys. Cytology findings were compatible with a malignant round cell tumor. The most probable diagnosis was neuroblastoma. Following a comprehensive discussion with the owners about a treatment plan, surgical excision was performed. Because a wide excision would compromise major vessels, excision was performed after careful dissection of the aorta and vena cava. The left kidney was removed because the proximal ureter could not be separated from the tumor. The animal recovered successfully. Diagnosis was confirmed by histopathology and immunohistochemistry, but the owners decided not to pursue any further treatment. Clinical signs of abdominal pain recurred within 1 month following surgery. Therefore, the animal was euthanized upon the owners' request. This report describes the diagnosis, surgical treatment, and follow-up of a dog with an abdominal peripheral neuroblastoma.

Disseminated peripheral neuroblastoma in a Rhodesian Ridgeback dog

CASE REPORT

A 4-year-old neutered male Rhodesian Ridgeback dog with right-sided Horner's syndrome, bilateral laryngeal paralysis, neck pain and bilateral hindlimb ataxia was euthanased following deterioration of its neurological status. Necropsy examination revealed an off-white retropharyngeal neoplastic mass (100 × 30 × 30 mm) attached to the base of the skull on the right side and macroscopic nodular metastases in the spleen and three vertebral bodies (C6, C7 and T6), including a nodule attached to the dura at C7. Histological evidence of neuroblastic tumour was detected in these macroscopic lesions, a regional lymph node, bone marrow of a femur and all 15 vertebral bodies (C1-T8) examined, including the three with macroscopic metastases, and in the lumens of small blood vessels in the lungs and liver. Ganglion cell differentiation was detected only in the primary retropharyngeal mass, one splenic nodule and the C7 dural nodule. Neoplastic cells were immunoreactive to neurofilament protein (ganglion cells only), vimentin and synaptophysin, and were negative for S100 protein, GFAP, CD3 and Pax5.

CONCLUSION

The diagnosis was disseminated peripheral neuroblastoma, differentiating subtype (International Neuroblastoma Pathology Classification), with likely primary involvement of the right cranial cervical ganglion. This appears to be the first report of neuroblastoma in a dog with widespread occult haematogenous metastasis to bone marrow.

Multiple cutaneous ganglioneuromas in a dog

A 3-year-old male Labrador retriever dog was presented with multifocal small cutaneous nodules, distributed mainly over the thoracic wall, the flank and the scrotum. The dog was otherwise in good health and had no significant past medical history. Radio- and sonographic examination revealed no evidence of internal tumours, including endocrine tumours. Histological examination of two excised samples revealed round, non-ulcerated nodules in the superficial corium, characterized by two different neoplastic cell components and mild inflammation. The first tumour cell population showed histomorphological characteristics of mature ganglion cells; the second featured small, spindle-shaped tumour cells with scant cytoplasm. Both neoplastic cell components expressed vimentin, neurofilament protein, pan-neuronal neurofilament, amyloid-precursor protein and chromogranin A. In addition, the spindle-shaped tumour cells were positive for 2', 3'-cyclicnucleotide 3'-phosphodiesterase. The findings had many histological and immunohistochemical features in common with primary cutaneous ganglioneuromas in humans, enabling the canine tumours to be also classified as multiple cutaneous ganglioneuromas.

Morphology of experimentally induced tumors of the sympathetic nervous system in rats

Seventeen tumors of the sympathetic nervous system were discovered in offspring of rats exposed in utero at a single dose of 80mg/kg of N-nitrosoethylurea at the day 16-19 of pregnancy, and then to constant light regimen. These tumors were classified as follows: benign--ganglioneuroma (six cases) and malignant--ganglioneuroblastoma (four cases) and neuroblastoma (seven cases). The most frequent location was in the sympathetic trunk in the mediastinum and in the retroperitoneal space. Morphological features of these induced tumors represent a model for similar neoplasms in humans in childrens' age.

Canine Ganglioneuroblastoma in the Oral Mucosa

A ganglioneuroblastoma of the oral cavity in a dog was examined histologically and immunohistochemically. This rare neoplasm was considered to be derived from ectopic neural crest cells. This is the first report of a canine ectopic ganglioneuroblastoma located in the oral mucosa.

Peripheral neuroblastoma in a young labrador retriever

A 2-year-old Labrador Retriever developed atrophy of the right temporal muscle, subsequently showed generalized seizure and died 2 months after the clinical onset. Postmortem examination revealed the tumor masses in the right mandibulopharyngeal area, nasopharynx and intracranial space. Histopathologically, these tumor masses were composed of small round neoplastic cells and neuropil-like stroma separated by fibrovascular septa. In the neoplastic masses, small neoplastic cells with round to oval hyperchromatic nuclei and scanty cytoplasm predominated, and angulated neoplastic cells with larger nuclei and moderate cytoplasm were scattered. Immunohistochemically, neoplastic cells were positive for neuron specific enorase, neurofilament protein, chromogranin A, synaptophysin and tyrosine hydroxylase. Based on these findings, this case was diagnosed as peripheral neuroblastoma, presumably originated from the sympathetic ganglion, maybe right craninal cervical ganglion.

Peripheral neuroblastoma in a young Beagle dog

A peripheral neuroblastoma was found in the abdominal cavity of a young male beagle dog. The large tumor mass involved the left kidney and both adrenal glands. Histologically, a major portion of the neoplasm consisted of lobulated sheets of small round cells with hyperchromatic nuclei mixed with polygonal cells and neuropil. Small clusters of polygonal cells with abundant eosinophilic cytoplasm and a trabecular growth pattern were observed adjacent to some of the tumor lobules. Small, round neoplastic cells metastasized to lumbar lymph nodes and also to the adrenal glands. The neoplastic cells were positive for neuron-specific enolase, synaptophysin, and neurofilament protein. Electron micrographs revealed intracytoplasmic dense core granules, microtubules, intermediate filaments, and desmosomes in the cytoplasm of the neoplastic cells.

Peripheral neuroblastoma in a dog

Primitive neuroectodermal tumors are composed of primitive neuroepithelial cells and include tumors of the central and peripheral nervous system. Neuroblastoma, medulloblastoma and retinoblastoma are examples of these rare malignant tumors that usually occur in young patients. This report describes a peripheral neuroblastoma in a 2 year old Boxer that presented with signs of renal disease and a palpable abdominal mass. The purpose of this paper is to describe the clinical presentation, imaging and immunohistological studies of this abdominal tumor in a young dog and to review the literature.

Intracranial gangliocytoma in a dog

The clinical, pathologic, immunohistochemical, and electron microscopic characteristics of a pure intracranial gangliocytoma in a 6-year-old spayed female dog are presented. The tumor is very rare in humans, and has not been previously reported in the dog. The most remarkable feature of this tumor was that it was composed of a single neuronal cell type without the presence of glial elements, as demonstrated by the negative immunohistochemical reaction to glial fibrillary acidic protein.

Morphology of experimental tumors of the sympathetic nervous system

The morphology of experimental tumors of the sympathetic nervous system in rabbits and hamsters induced by administration of nitrose compounds and the use of modifying factors were studied. The tumors were localized in the mediastinum, retroperitoneal space, adrenals and kidneys. A predominant involvement of the female animals was observed. Histological, histochemical and electron microscopic studies of 33 tumors of the sympathetic nervous system were carried out. By their degree of maturity the tumors were classified as ganglioneuromas, ganglioneuroblastomas and neuroblastomas. By their structure the experimental tumors were similar to the analogous neoplasias of man.