Ten cases of angiosarcoma of the liver among vinyl chloride workers from a plant in Shawinigan, Québec, are reported. The author insist mostly on the occupational history of these workers and on the morphologic description of the lesions. A pathogenic hypothesis is submitted.
Due to the claim of an association between focal nodular hyperplasia of the liver, benign hepatomas and oral contraceptives, the files in the departments of pathology at the university hospitals in Lund and Malmö were examined for these two diagnoses made since 1945 and 1957, respectively. 26 cases of focal nodular hyperplasia of the liver and 7 benign hepatomas were found, 18 and 2, respectively, in women. Since 1963, the year before oral contraceptives were introduced in Sweden, focal nodular hyperplasia has been diagnosed in 8 women in the reproductive period of life; 4 of these had taken oral contraceptives. The 4 diagnoses were established in 1972-1974. At most, 25 per cent of Swedish females between the ages of 15 and 44 years have been on oral contraceptives. The Swedish series of 28 patients with focal nodular hyperplasia comprised 3 epileptics and 3 diabetics. At least two of the epileptics had been treated with barbiturates and/or hydantoins. The prevalence of drug-treated epilepsy in Sweden is 0.4-0.5 per cent, and of diabetes about 2 per cent. The possible aetiological role of drugs provoking an increase of the smooth-surfaced endoplasmic reticulum of the liver and proliferation of vascular fibrous tissue in a part of the liver which preveiously may have been damaged by vascular disturbances or trauma, is considered. No relationship between benign hepatomas and drugs was found. The observations support the notion that oral contraceptives may be of aetiological importance in the development of focal nodular hyperplasia of the liver, although the material is too small for epidemiological and statistical analysis.
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.