Tumours and related lesions of the endocrine system of bony and cartilaginous fishes |
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| Authors: | Leatherland & Down |
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| Institution: | Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada; Fisheries Management Branch, British Columbia Ministry of, Agriculture, Food and Fisheries, PO Box STN PROV GOVT, Victoria, British Columbia V8W 9M2, Canada |
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| Abstract: | The literature pertaining to the prevalence and histopathology of endocrine cell and tissue tumours and related lesions (TRL) in bony and cartilaginous fishes is catalogued and reviewed in the context of the embryological origin of the various components of the endocrine system. Reports of TRLs of endocrine cells or tissues of fishes are relatively rare, and of these, most describe thyroid neoplasms that appear to be simple hyperplasia. The vast majority of published reports of endocrine TRLs in fishes are case-studies, and thus, with a few notable exceptions, the aetiology of the lesions is unknown. The exceptions include the epizootics of thyroid neoplasms in introduced Pacific salmon in the Great Lakes, which appear to have an environmental aetiology, and epizootics of gonadal stromal cell neoplasms. The latter were all found in either hybrid species or highly inbred captive strains of fishes, suggesting a genetic involvement in the tumourigenesis. The possible aetiologies for the reported TRLs in wild and captive fish species are discussed, and various hypotheses proposing infectious agents, genetic factors and environmental contaminants are considered. |
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| Keywords: | granulosa cells inter-renal gland Leydig cells neurosecretory cells pituitary gland Sertoli cells thecal cells thyroid tissue tumours |
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