title: Ultrasonographic and pathologic study of schwannoma in a Goldfish (Carassius auratus).
abstract: An adult Goldfish (Carassius auratus) developed an exophitic, multinodular, mass in the dorsal region involving the fin. The clinical and pathologic approach included ultrasonography, cytology, histopathology, immunohistochemistry, and ultrastructural evaluation. B-mode and color Doppler ultrasonographic findings showed an oval, well-defined mass with slightly inhomogeneous parenchymatous echotexture associated with an intense intralesional vascularization. Cytology and histology revealed neoplastic pleomorphic spindle cells arranged in a storiform pattern or in palisades typical of Antoni A pattern schwannoma. Moderate anisocytosis and anisokaryosis and occasional binucleation were also present. The neoplastic tissue deeply infiltrated the skeletal muscle of the dorsal region. Immunohistochemistry showed a diffuse cytoplasmic immunoreactivity of neoplastic cells to S100 protein and proliferating cell nuclear antigen (PCNA); glial fibrillary acidic protein was negative. The PCNA proliferation rate was 23.5% (calculated as the mean of 10 fields). Ultrastructurally, neoplastic cells were juxtaposed with parallel nuclei forming the typical palisade pattern and sharing cytoplasmic and nuclear features with human schwannoma. This is the first cytologic description supplied with echographic investigation of a malignant schwannoma in a fish species.
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: Rubina
authors.initials: R
authors.lastname: Sirri
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Diana
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Scarpa
authors.affiliation: Department of Veterinary Medicine, University of Perugia, Perugia, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Brachelente
authors.affiliation: Department of Veterinary Medicine, University of Perugia, Perugia, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vitellozzi
authors.affiliation: Luca Ceredi Koi Farm snc, Cesena, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Ceredi
authors.affiliation: Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Mandrioli
mesh_terms: D000818:Animals; D005393:Fish Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D006054:Goldfish; D009442:Neurilemmoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D014463:Ultrasonography
keywords: Cytology; PNST; echography; fish; immunohistochemistry; ultrastructure