First description of an olfactory neuroblastoma in goldfish Carassius auratus: a case report

Abstract

An external pinkish growing mass that emerged from the right nostril of an adult goldfish Carassius auratus L. was evaluated by means of light microscopy and immunohistochemistry. The neoplasm presented a well-developed fibrovascular stroma associated with solid cell nests and a large number of Flexner-Wintersteiner rosettes. Myelinated fibres were observed around them. Neoplastic cells showed a prominent degree of nuclear atypia and low mitotic activity. The latter was in agreement with the low reactivity of tumour cells to anti-proliferating cell nuclear antigen antibody. Immunohistochemistry also revealed anti-neuronal nitric oxide synthase, anti-S100 protein, antineuropeptide Y, and anti-cytokeratin immunoreactivity in tumour cells as well as in normal olfactory epithelium of goldfish control sections. Histopathological and immunohistochemical findings strongly suggest a diagnosis of an olfactory neuroblastoma (ONB). To our knowledge this is the first description of ONB in goldfish. KEY WORDS: Tumour · Olfactory neuroblastoma · Goldfish · Carassius auratus · Histopathology · Immunohistochemistry Resale or republication not permitted without written consent of the publisherDis Aquat Org 96: [61][62][63][64][65][66][67][68] 2011 MATERIALS AND METHODSAn adult goldfish Carassius auratus L. was referred to a private veterinary clinic located in Rosario City, Argentina. The specimen showed an external pinkish growing mass emerging from the right nostril. The roughly shaped mass of approximately 0.5 cm in diameter was excised, fixed in 10% v/v buffered formaldehyde solution and submitted to the Diagnostic Pathology Service of the School of Veterinary Sciences-National University of Rosario, Argentina. The sample was dehydrated in a graded series of ethanol and embedded in paraffin wax. Sections of 3 to 5 µm in thickness were stained using haematoxylin and eosin, combined periodic acid-Schiff (PAS)/Alcian blue, the Grimelius technique and Tolivia staining.In order to define the origin of the presumptive tumour, an immunohistochemical study was carried out. Unless otherwise stated, all incubations were performed at room temperature in a humid chamber, and all washing procedures consisted of 3 successive 5 min immersions in 0.1 M phosphate-buffered saline (PBS). Endogenous peroxidase activity was blocked by incubation in Peroxidase Blocking Reagent (Dako) for 30 min, and after a rinse in PBS, antigens were exposed by heating under pressure in different buffer solutions or by incubating the samples with proteolytic enzymes depending on the primary antibody employed ( Table 1). The sections were subsequently washed again with PBS, treated with 3% skimmed milk powder for 15 min to block non-specific antibody binding, incubated with the primary antibody as indicated in Table 1, washed with PBS, and incubated for 30 min with anti-mouse or anti-rabbit EnVision+ System Labelled Polymer-HRP (DakoCytomation). After further rinsing, the sections were finally developed using 3, 3-diaminobenzidine tetrahydrochloride...

Of mice and men: olfactory neuroblastoma among animals and humans

“…On the other hand, lobular architecture and low mitotic activity are with parallel to cases of ONB described in man. Comparing ONB cases reported in other species described in this article, goldfish ONB differs to higher extent from human and mammal neoplasms (Table ) …”

“…However, no specific reactivity was observed for NSE, NF, GFAP and synaptophysin, either in tumour or in goldfish control sections. And this is the major and significant difference between the fish ONB and the rest of human and animal cases of this neoplasm described in this review …”

“…Comparing ONB cases reported in other species described in this article, goldfish ONB differs to higher extent from human and mammal neoplasms ( Table 4). 17 Immunohistochemistry studies of fish ONB sections revealed diffuse pattern of S-100 immunostaining, positive cells were mainly located in rosettes and solid nests. In addition, the majority of cells of rosettes and the solid nests were also positive for cytokeratin staining.…”

“…Reports on the application of these classification systems of ONBs in animals are limited. However, due to the similarities between tumours in man and domesticated animals, both classification systems appear to be applicable and were utilized in a few studies on ONB in animals, which have been conducted recently …”

“…However, due to the similarities between tumours in man and domesticated animals, both classification systems appear to be applicable and were utilized in a few studies on ONB in animals, which have been conducted recently. 7,11,17 Despite the advances in histopathology and immunohistochemistry, there are still some difficulties in unambiguous diagnosis of ONB. One of the main problems is similarity between this tumour and sinonasal undifferentiated carcinoma (SNUC), malignant melanoma and neuroendocrine carcinoma.…”