Strain C3H-A-vy-fB mice: ninety percent incidence of mammary tumors transmitted by either parent.

Mammary tumorigenesis in C3H-A(vy)fB female mice is not due to milk-borne mammary tumor virus but to factors transmitted at conception. Prominent among these is the A(vy) gene which may increase the virulence or transmissibility of a variant of mammary tumor virus vertically transmitted by either parent, or may increase the tumorigenic response of the mammary tissue. These factors together with the influence of hormones of pregnancy resulted in the high incidence observed.

Hyperplastic and neoplastic alterations in the livers of white perch (Morone americana) from the Chesapeake Bay.

White perch (Morone americana) sampled from 15 estuaries of the Chesapeake Bay contained a variety of hyperplastic and neoplastic alterations in their livers. The lesions were derived from bile ductular epithelium and/or hepatocytes. The biliary lesions consisted of hyperplasias and adenomas. The hepatocellular lesions consisted of focal populations of altered cells and neoplasms, of clear-cell and basophilic morphologic appearance. The hepatocellular lesions were conspicuous in the absence of the decreased amount of copper accumulation. In this respect, the cells comprising these lesions are reminiscent of cells from hepatocellular neoplasia in mice and rats resistant to accumulation of iron.

Neoplastic and nonneoplastic hepatic changes in lake whitefish (Coregonus clupeaformis) from the St. Lawrence River, Quebec, Canada.

As part of a survey of fish diseases, lake whitefish (Coregonus clupeaformis) were collected in fall 1995 from the St. Lawrence River 15 km upstream of Quebec City, Quebec, Canada, to assess the prevalence of liver lesions. A total of 141 fish were captured and necropsied, and three standard sections of liver were taken for histological examination. Prevalences of altered hepatocyte foci, hepatocellular carcinoma, cholangioma, and cholangiocarcinoma were 0.7%, 2.1%, 0.7%, and 2.1%, respectively. Thus, the overall prevalence of liver neoplasia was 4.9% (7/141). Hepatic tumors were only observed in fish 7 years old or older. Fish age was significantly and positively correlated with the index assessing the number and size of macrophage aggregates (p<0.001; rs = 0.16). Hepatocyte vacuolation, anisokaryosis, lymphocytic infiltration, and bile duct hyperplasia were also observed but were not related to the age, length, sex, or condition factor of the fish. These results represent the first report on a series of hepatic tumors in a wild salmonid species.

Hepatomas and other neoplasms in the atlantic hagfish (Myxine glutinosa): a histopathologic and chemical study.

M. glutinosa is a cyclostome, living in the mud in seawater of high salinity. It probably is a stationary scavenger feeder. About 28,000 hagfish from the Gullmar Fjord were examined during a 5-year period for the occurrence of tumors. Hepatomas were found to be predominant neoplasm, observed at a frequency that decreased from 5.8% in 1972 to 2.9% in 1973 and finally to 0.6% in 1974--76. Islet cell hamartomas and frank neoplasms decreased from 0.5% in 1972 to less than 0.1% in 1973--76. Occasional subcutaneous and mesenterial neoplasms were also observed during 1972--74. In hagfish caught 12 km out in the open sea, the hepatoma incidence decreased from 2.8% in 1972 to 0.9% in 1974. Given this background, it is possible that pollution of the Gullmar Fjord by carcinogenic substances with low biodegradability has occurred until 1972, and this pollution could be of etiologic significance for these hagfish tumors. In fact, the use of PCBs became prohibited by law in Sweden in 1971--72. Severe restrictions were also introduced for the use of chlorinated pesticides, notably DDT, and associated substances (DDD, DDE). Preliminary analyses for the presence of PCBs, DDT (and its metabolites), and aflatoxins (the notorious hepatocarcinogen) were performed by gas chromatography and thin-layer chromatography. Livers (with and without neoplasms) from hagfish caught inside the threshold of the fjord contained about 5 mg/kg of wet weight of PCBs and about 0.1--0.4 mg/kg of dry weight of DDT, DDD, or DDE, whereas those from hagfish caught in the open sea had a much lower PCB concentration (about 0.2 mg/kg of wet weight). No PCBs and no chlorinated pesticides were found in analyses of the mud at the catching site. High PCB concentrations (3 mg/kg of wet weight) were, however, observed in livers from cod living in the Gullmar Fjord, and it was proposed that bony fish may be the source of hagfish liver PCBs. PCB chromatograms of hagfish livers differed from those of PCB standards and cod liver. This strange pattern, which was not seen in livers from hagfish caught in the open sea, might be explained by an unusual mode of metabolization. The assays for aflatoxins gave completely negative results.

Cholangiocarcinoma in a blue-fronted Amazon parrot (Amazona estiva).

A case of cholangiocarcinoma in a 3-year-old blue-fronted Amazon parrot (Amazona estiva) is reported. Neoplastic tissue was limited to the liver, where it infiltrated and replaced much of the hepatic parenchyma. The only other reported cases of cholangiocarcinoma in an Amazon parrot (Amazona xanthops) also occurred in a bird in its fourth year of age.

Cholangiocarcinoma in a yellow-faced Amazon parrot (Amazona xanthops).

A cholangiocarcinoma in a 3 1/2-year-old yellow-faced Amazon parrot (Amazona xanthops) is reported. The parrot presented with a prolapsed cloaca and died after a 6-week clinical course of progressive weight loss. The tumor replaced much of the normal hepatic architecture but apparently did not metastasize. Cholangiocarcinomas have been reported rarely in several species of domestic and captive wild birds, but this appears to be the first reported case in a large psitticiform bird.

Cholangiocarcinoma in a 4-month-old double yellow-cheeked Amazon parrot (Amazona autumnalis).

A cholangiocarcinoma was diagnosed in a 4-month-old double yellow-cheeked Amazon parrot (Amazona autumnalis). Histologically, neoplastic cells effaced hepatocellular architecture. Ultrastructurally, variably dilated bile ductules were lined by simple cuboidal to low columnar ciliated epithelial cells with sparse cellular organelles and prominent junctional complexes. Elongated single cilia arising from basal bodies in the apical cytoplasm were occasionally evident. The presence of such a neoplasm in a 4-month-old parrot is extremely unusual.

Health of lake whitefish (Coregonus clupeaformis) with elevated tissue levels of environmental contaminants.

Lake whitefish (Coregonus clupeaformis) were collected in 1996 from the St. Lawrence River, Quebec, Canada. Histologic examination was performed on major organs of 497 specimens and on the liver of 48 additional individuals. Preneoplastic and neoplastic hepatic changes consisted of vacuolated cell (n = 65), clear cell (n = 17), and acidophilic (n = 16) foci of altered hepatocyte, hepatocellular carcinoma (n = 12), cholangioma (n = 5), and cholangiocarcinoma (n = 28). Six fish were intersexes (1.2%), and 11.7% of the ovaries (26/223) had ducts containing spermatogonia or more differentiated cells of the male germ cell line. Asynchronous nodular maturation of the testes was present in 8.2% of the male fish (22/267). The mean hepatic concentrations of various contaminants, including polychlorinated biphenyls (PCBs), chlorobenzenes, pesticides, and trace metals, were 6 to 8 times higher in lake whitefish than in three other fish species (Ictalurus punctatus, Catostomus commersoni, and Stizostedion vitreum) collected at the same site. Condition factor of lake whitefish from this study was lower than that previously reported 40 to 50 years ago at this site and from contemporary pristine sites in the Great Lakes, USA. The presence of liver neoplasms, gonadal lesions, and a decreased condition factor in lake whitefish from the St. Lawrence River may be etiologically related to elevated tissue concentrations of toxic chemical contaminants.

Hepatocholangioadenoma in a pig.

A Landrace sow had several neoplastic nodules in the liver. Histopathologically, the individual nodules consisted of two types of closely associated neoplastic cells; one was of hepatocellular type, the other of cholangiocellular type. Based on this finding, the term "hepatocholangioadenoma" is considered to be appropriate for this tumour. Previously reported in man, the dog and the duck, a mixed type of primary hepatic neoplasm has now been found in the pig.

Primary hepatic tumours in cattle. A classification of 66 cases.

A study of 66 primary hepatic tumours was carried out on cattle. These consisted almost entirely of adult females. Fifty hepatocellular tumours (10 adenomas and 40 carcinomas), 10 cholangiocellular tumours (three adenomas and seven carcinomas), two cavernous haemangiomas, two haemangioendothelial sarcomas, one fibroma and one Schwannoma were diagnosed. The 50 hepatocellular tumours were classified into adenomas (20 per cent) and carcinomas (80 per cent), both prevalent in the solitary macronodular form. The hepatocellular carcinomas were divided into six groups based on their distinctive histological arrangement and the morphology of the neoplastic cells: trabecular (55 per cent), pseudoglandular (10 per cent), solid (12 per cent), scirrhous (12 per cent), pleomorphic (7 per cent) and fibrolamellar (2 per cent). Twenty-seven of 50 hepatocellular tumours (54 per cent) were associated with features of blood-filled lakes resembling telangiectasis within the neoplastic tissue. Metastasis was uncommon (10 per cent of hepatocellular carcinomas) and grading according to Edmondson's system (1958) showed a low level of anaplasia in most carcinomas (55 per cent). An association with cirrhosis was never found.

Ulex europaeus agglutinin 1 lectin histochemical staining of dog hepatocellular and bile duct carcinomas.

Ulex europaeus agglutinin 1 (UEA-1) lectin-binding is a feature of canine intrahepatic bile duct epithelial cells but not of canine hepatocytes. In tumours diagnosed histologically as cholangiocarcinomas or hepatocellular carcinomas, UEA-1 staining occurred in tumour cells regardless of histological appearance. The division of primary liver carcinomas into different presumed cell types of origin is not reflected by equivalent differentiation of the tumour cells and is not of diagnostic value.

Cholangioma in white perch (Morone americana) from the Chesapeake Bay.

Cholangiomas found in two of 21 wild-caught white perch (Morone americana) from the Chesapeake Bay are described. The two fish were part of a study investigating a condition of abnormal hepatic copper storage in this species. The tumors were superficial, solitary masses consisting of cuboidal to columnar cells in tubuloglandular arrangement. Mild to marked peribiliary inflammation and fibrosis was seen also. Environmental pollution, the condition of abnormal copper storage, peribiliary fibrosis, and/or parasites may have contributed to the development of these tumors.

Extrahepatic biliary carcinoma in sloth bears.

Extrahepatic biliary carcinoma was found in each of 5 adult sloth bears that died between 1970 and 1984 while on exhibit in Ohio zoos. The tumor was characterized by numerous mucin-producing neoplastic glands scattered throughout abundant fibrous stroma. The cause of the tumor was not determined.

Acquired myasthenia gravis and cholangiocellular carcinoma in a dog.

Acquired myasthenia gravis and cholangiocellular carcinoma were diagnosed in a 7-year-old English Setter referred because of forelimb lameness, exercise-induced weakness, and fever. Three months earlier, the dog had had a pleuropulmonary infection caused by a Fusobacterium sp. The concurrent development of myasthenia gravis and cholangiocellular carcinoma in this dog may be explained by a paraneoplastic syndrome, although it is unproven. The cholangiocellular carcinoma may have possessed an acetylcholine receptor-like antigen on the tumor surface, which induced autoantibodies to cross-react with acetylcholine receptors at the neuromuscular junction.

Nonhematopoietic hepatic neoplasms in cats: 21 cases (1983-1988).

Nonhematopoietic hepatic neoplasms (n = 25) were diagnosed in 21 cats during a 5.5-year period. Thirteen of the neoplasms were benign bile duct adenomas and 12 were malignant, 6 of which were bile duct adenocarcinomas. All cats were greater than or equal to 10 years old, and 14 were male. Main clinical signs were anorexia and lethargy, and 15 of 21 cats had hepatomegaly. All 21 cats were feline leukemia virus-test negative. Although there was a trend toward high activities of serum alanine transaminase and aspartate transaminase, neither clinical signs nor enzyme activity were specific for diagnosis of hepatic neoplasia in the cats of this study.

Hepatic neoplasia.

The clinicopathologic features of hepatic neoplasms such as hepatocellular adenomas, hepatocellular carcinomas, bile duct carcinomas, and hepatic carcinoids are presented. The authors also discuss the diagnostic and therapeutic approaches to hepatic neoplasia.

[Duck hepatitis B virus DNA in multiple primary cancers and metastatic tumors in duck liver].

Duck hepatitis B virus (DHBV) DNA was detected in both multiple primary cancers and intrahepatic metastatic tumors in duck liver by Southern blot technique. Among 7 ducks with multiple primary tumors in the liver, the banding pattern of integrated DHBV DNA in different tumors was identical in 3 animals but different in 2. One duck showed a similar hybridization pattern in different tumor nodules and the remaining one was negative for DHBV DNA. Integrated DHBV DNA was also identified in one duck with metastatic tumor in the lung, in which the hybridization pattern was the same as that of the primary hepatocellular carcinoma. The presence of the same distinct hybridization bands in various tumor nodules indicated that they may arise from the same clone of neoplastically transformed cell. Different hybridization bands showed that tumors may arise from different clones. The results suggest that hybridization pattern of hepatic carcinoma with viral DNA probe could be used as a clone marker of transformed cells to distinguish multiple primary hepatic cancers from intrahepatic metastasis.