Neoplasms of the Urinary Tract in Fish

Abstract

The veterinary literature contains scattered reports of primary tumors of the urinary tract of fish, dating back to 1906. Many of the more recent reports have been described in association with the Registry of Tumors in Lower Animals, and most of the spontaneous neoplasms of the kidney and urinary bladder are single case reports. In rare instances, such as described in nephroblastomas of Japanese eels and tubular adenomas/adenocarcinomas of Oscars, there is suggestion of a genetic predisposition of certain populations to specific renal neoplasms, environmental carcinogenesis, or potentially an unknown infectious etiology acting as a promoter. Hematopoeitic neoplasms have been infrequently described as primary to the kidney of a variety of fish species, and therefore those case reports of renal lymphoma and plasmacytic leukemia are addressed within the context of this review.Keywords fish and marine animals, wildlife, urinary tract, oncologyBetween 30 000 and 40 000 species of fish have been reported in the literature and included in a variety of taxonomic classes falling under the infraphylum Gnathostomata or jawed vertebrates, which further consists of the extant class Chondrichthyes or cartilaginous fish and superclass Osteichthyes or the bony fish. 37 Within that enormous number of species, there is an extraordinary variety of structure and physiology, with species ranging in size from the smallest recorded fish (Paedocypris progenetica), measuring a mere 7.9 mm, 48 to the whale shark (Rhincodon typus), measuring up to 20 m in length. 15 It is therefore reasonable to expect that the pathology of fish encompasses an immense domain of entities and pathogeneses, representing a boundless field of potential discovery in veterinary pathology, particularly concerning spontaneous neoplastic disorders. The current paucity of information is due in large part to the environment in which the subjects live, the lack of our ability to track individuals throughout their range, and the fact that autolysis and predation affect the vast majority of samples, leaving the pathologist with a limited caseload of spontaneous neoplasms within wild populations. On the other hand, zoo and aquarium populations, private tropical and marine aquaria, and farmed fish are providing veterinary pathologists with a steady flow of novel entities and new interactions between host species and disease.The following review of neoplastic disease in the urinary system of bony and cartilaginous fishes relies heavily on the body of knowledge accumulated by the National Cancer Institute's Registry of Tumors in Lower Animals (RTLA) (Experimental Pathology Laboratories, Inc, Sterling, VA), which were donated from myriad sources as well as from the diligence of those researchers who have published their findings in the international literature. In addition, other sources were consulted as part of this review to include the Armed Forces Institute of Pathology (AFIP) archives, the Smithsonian National Zoo, department of pathology, and through the gene...

Nephroblastoma in bester sturgeon, a cultured hybrid of Huso huso × Acipenser ruthenus: Diagnostic imaging, clinical and histopathological study

“…Primary renal neoplasia in higher vertebrates is predominantly split into the two most common forms, being nephroblastomas and some variant of adenocarcinomas. This appears to be statistically true within fish as well, with the vast majority of both spontaneous and experimental renal neoplasms falling into one or the other diagnostic group (Lombardini et al., ; Rahmati‐Holasoo et al., ).…”

“…The nephroblastoma is a triphasic mixture of embryonic epithelium (glomerular buds and tubules), undifferentiated blastema and myxomatous mesenchyme (stroma) in various amounts. Presence of embryonic or abortive glomerular structures and renal location are considered as the most critical keys to the diagnosis (Lombardini et al., ; Meuten & Meuten, ). Based on these characteristics, our clinical and histopathologic findings were consistent with nephroblastoma.…”

“…Nephroblastoma is traditionally described as an embryonal organoid tumour composed of neoplastic cells originating from the embryonic kidney from the metanephric blastema (Lombardini, Hard, & Harshbarger, ). It often contains incompletely formed renal tubules and glomeruli (Harshbarger & Slatick, ).…”

Telangiectatic osteosarcoma and renal adenocarcinoma in an Oscar (Astronotus ocellatus, Agassiz): Diagnostic imaging and immunohistochemical study

“…Primary renal neoplasia in higher vertebrates is predominantly split into two common forms, nephroblastomas and some variant of renal adenomas. This appears to be true within fish as well, with the vast majority of both spontaneous and experimental renal neoplasms falling into one or the other diagnostic group (Lombardini, Hard, & Harshbarger, ). Nephroblastoma is the most common primary renal tumour in fish.…”

“…Nephroblastoma is the most common primary renal tumour in fish. The second largest group of spontaneous renal neoplasms consists of the epithelial tumours comprising various subtypes of adenomas and adenocarcinomas (Lombardini et al., ). There are only rare reports of renal tubular cell tumours in the literature occurring in fish.…”