Peripheral neuroblastoma in a young labrador retriever

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.

A case of olfactory ganglioneuroblastoma in a dog: immunohistochemical comparison with olfactory neuroepithelia and olfactory neuroblastomas

In the present study, histopathological and immunohistochemical findings of olfactory ganglioneuroblastoma in a dog were compared to those of canine olfactory neuroepithelia and neuroblastomas. Olfactory ganglioneuroblastoma consists of ganglion cell-like tumor cells with Schwannian stroma and neuroblast-like tumor cells. Immunohistochemically, ganglion cell-like tumor cells were immunopositive for synaptophysin, β3-tubulin, and tyrosine hydroxylase, Schwannian stroma was immunopositive for GFAP and SOX2, and neuroblast-like tumor cells were immunopositive for OLIG2, β3-tubulin, SOX2, cytokeratin AE1/AE3, and p63. The immunohistochemical results of olfactory neuroepithelia and olfactory neuroblastomas were similar to those of neuroblast-like tumor cells. These results suggest that the ganglion cell-like tumor cells in the present case have a sympathetic neuron immunophenotype, whereas neuroblast-like tumor cells have an olfactory neuroepithelial immunophenotype.

Enteric peripheral neuroblastoma in a calf

An 11-month-old female Japanese Black calf had showed chronic intestinal symptoms. A large mass surrounding the colon wall that was continuous with the colon submucosa was surgically removed. After recurrence and euthanasia, a large mass in the colon region and metastatic masses in the omentum, liver, and lung were revealed at necropsy. Pleomorphic small cells proliferated in the mass and muscular layer of the colon. The cells were positively stained with anti-doublecortin (DCX), PGP9.5, nestin, and neuron specific enolase (NSE). Thus, the diagnosis of peripheral neuroblastoma was made. This is the first report of enteric peripheral neuroblastoma in animals. Also, clear DCX staining signal suggested usefulness of DCX immunohistochemistry to differentiate the neuroblastoma from other small cell tumors in cattle.

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.

Peripheral neuroblastomas in dogs: a case series

The peripheral neuroblastic tumours (PNTs) include neuroblastoma, ganglioneuroblastoma and ganglioneuromas. These subtypes reflect a spectrum of differentiation of progenitor cells of the sympathetic nervous system from tumours with predominant undifferentiated neuroblasts to those consisting of neuronal cell bodies that are well differentiated. Peripheral neuroblastoma is a tumour composed of neuroblastic cells with no or limited neuronal differentiation. In dogs, peripheral neuroblastoma is rare. The present report documents nine cases of canine peripheral neuroblastoma, the majority occurring as large masses in the craniodorsal abdominal cavity of young dogs (mean age of 3 years at diagnosis). Microscopically, all of the masses consisted of round to oval cells with a scant cytoplasm and hyperchromatic nuclei. Homer-Wright rosettes and pseudorosettes were evident in three of the nine cases. Neoplastic cells were immunoreactive in varying degrees to S100, neuron-specific enolase, synaptophysin, chromogranin A, tyrosine hydroxylase (one case) and were negative for vimentin, cytokeratin, CD3 and CD79a, indicating a neurogenic nature. Four of the nine cases occurred in Labrador retrievers (44%) and two (22%) in boxers, suggesting a possible breed predisposition.

Diagnostic immunohistochemistry of canine and feline intracalvarial tumors in the age of brain biopsies

The focus of immunohistochemistry as applied to nervous system tumors is in identifying the neoplasm present and evaluating margins between normal and neoplastic tissue. Although not always utilized by specialists in neuropathology, immunohistochemistry remains useful to resolve concerns about the differentiation and rate of tumor growth. The aims of this review are to discuss the utility of immunohistochemical reagents currently used in diagnosis of canine and feline intracalvarial tumors, to indicate the applicability of some tests currently used in human nervous system tumors for domestic species, and to evaluate a few less commonly used reagents. A panel of biomarkers is usually needed to confirm a diagnosis, with groups of reagents for leptomeningeal, intraparenchymal, and ventricular neoplasms. In the future, signature genetic alterations found among feline and canine brain tumors--as correlated prospectively with diagnosis, rate of enlargement, or response to treatment--may result in new immunohistochemical reagents to simplify the task of diagnosis. Prospective studies determining the type and proportion of stem cell marker expression on patient longevity are likely to be fruitful and suggest new therapies. Due to increased frequency of biopsy or partial resection of tumors from the living patient, biomarkers are needed to serve as accurate prognostic indicators and assist in determining the efficacy of developing therapeutic options in nervous system tumors of dogs and cats.

Cerebral neuroblastoma and pituitary adenocarcinoma in two budgerigars (Melopsittacus undulatus)

Case 1: A tumor mass involving the rostral part of left cerebrum was found in a two-year-old female budgerigar (Melopsittacus undulatus) at necropsy. Histologically, the neoplastic cells were arranged in sheets or cords and occasionally showed nest growth patterns. These uniform tumor cells had a little cytoplasm and ovoid or round basophilic nuclei with clearly distinct cytoplasmic membranes. The tumor cells were strong diffusely immunostained with both neuron-specific enolase (NSE) and neurofilament protein and partially for synaptophysin. They lacked chromogranin A, glial fibrillary acidic protein (GFAP), vimentin, S-100, and cytokeratin antigen expression. Moreover, they had no reaction to antibodies against pituitary hormones, such as adrenocorticotrophic hormone (ACTH), growth hormone, and prolactin. The histological and immunohistochemical examination determined the tumor as neuroblastoma. Case 2: An extremely enlarged pituitary mass was found above the sella turcica of a male budgerigar. It was soft and well delineated from the adjacent structures. On histological examination, this tumor consisted of a sheet of large closely packed polyhedral cells that had scant to a large amount of pale to strongly eosinophilic cytoplasm. The pleomorphic nuclei were apparently variable in shape, from small round hyperchromatic to very large vesicular forms. The cell boundaries were not clearly distinct. The multifocal immunolabelling of neoplastic cells for NSE, synaptophysin, GFAP, and ACTH appeared, whereas a few cells reacted with vimentin and S-100 and stained negative for other markers, which were also utilized for case 1. Histological and immunohistochemical findings led to identification of corticotroph adenocarcinoma in the pituitary gland.

Primary neuroblastoma in the skin of an adult shih tzu dog

A subcutaneous mass arising in the right gluteal area of an 11-year-old female shih tzu dog was surgically excised. Histologically, the mass was composed of small round or ovoid neoplastic cells that were arranged in nests of various sizes. The neoplastic cells generally had hyperchromatic nuclei and scanty eosinophilic cytoplasm, and were surrounded by a pale pink fibrillar area. Immunohistochemically, the neoplastic cells were positive for vimentin, S-100 protein, neurone-specific enolase and synaptophysin, but negative for cytokeratin, neurofilament protein, glial fibrillary acidic protein and chromogranin A. On ultrastructural observation, aggregates of thin cytoplasmic processes were frequently seen among the neoplastic cells. Based on these features, the tumour was diagnosed as a neuroblastoma. To the authors' knowledge, this is the first description of a neuroblastoma originating from the skin in an adult dog.