To assess whether the increase in malignant melanoma incidence could be due, at least in part, to changes in histological criteria of malignancy, pathologists in Australia, France, Italy, New Zealand, Norway, Sweden, the United Kingdom, the United States and the USSR reviewed diagnoses of 50 consecutive pigmented naevi (40 junctional and compound; 10 intradermal) and 20 consecutive malignant melanomas made in each participating centre around 1930, around 1955 and around 1980. Collaborating pathologists re-read the material, 2,665 cases in all, either from the original slide (82%) or from a recut block (17%), gave their diagnosis and indicated whether the lesion was benign (B), dubious benign (DB), dubious malignant (DM) or malignant (M). As the distribution of review diagnoses was much the same whether the original slide or one made from a recut block was read, the material was pooled. Overall, 2.8% of cases originally reported as B/DB were reviewed as DM/M, while 4.4% of the DM/M diagnoses were held to be B/DB. The shifts between categories were greatest around 1955 and least around 1980, suggesting increasing uniformity of interpretation. All available blocks were recut and sections sent to IARC for review: 1.7% (22) of 1293 B/DB diagnoses were considered to be DM/M and 3.3% (18) of 551 DM/M diagnoses were considered to have been B/DB. The consistently low frequency of shift in diagnostic category, whether the material was reviewed in the collaborating laboratories or by one pathologist at IARC, in a study designed to give maximum attention to those lesions--the junctional and compound naevi--in which a change in opinion as to malignancy would be most likely to arise, suggests that pathologists, irrespective of geographical location, are using common criteria. These findings argue against changes in histological interpretation as being responsible for more than a small portion of the continuous increase of some 3% to 8% per annum observed in malignant melanoma incidence. Other explanations, such as an increase in the frequency or potential for malignant transformation of precursor lesions, must be sought. The anatomical distribution of the malignant melanomas examined followed the usual site pattern by sex, and their thickness was observed to decrease over the period of the study in most centres.

A prospective cytogenetic study of patients with non-Hodgkin's lymphoma (NHL) presenting to one institution was commenced in 1983 as part of a larger study including histology, immunophenotyping, cytokinetics and survival. 175 patients were studied over 5 years and G-banded karyotypes were successfully obtained in 147. Chromosome abnormalities were detected in 135 cases (92%) with the commonest abnormality being t(14;18)(q32;q21) in 69 cases. Other non-random translocations were much less frequent, i.e. t(11;14) in seven cases and t(8;14) in four cases. Other specific structural changes included partial deletions of 6q (breakpoints ranging within q13-q23), 3q (breakpoints ranging within q21-q27), 1q and 10q22. Chromosome regions highlighted as being frequently involved in structural abnormalities were 11q13-q25, 1p22-p36, 3q21-q27 and 6q13-q23. Several specific recurring breakpoints were identified and these included 14q32, 18q21, 1p36 and 6q21. Frequently occurring numerical abnormalities were gains of chromosomes 3, 7, X and 12. Correlation with histological type showed, as expected, that t(14;18) was present in 89% of follicular lymphoma but also occurred in 30% of diffuse lymphoma. Abnormalities of 11q were correlated with the diffuse histologies as a group, whereas both numerical and structural abnormalities of chromosome 3 correlated with the diffuse large cell lymphoma (DLCL) subtype, and t(11;14) with diffuse small cleaved cell lymphoma (DSCCL). Although not statistically significant, abnormalities of 6q occurred twice as frequently in DLCL than in any other variety. However, several other commonly occurring abnormalities, such as extra copies of chromosomes 7, X, 12 and most of the structural abnormalities of 1p, did not correlate with any histological type. Therefore this large cytogenetic study has confirmed some previously reported correlations between specific chromosome abnormalities and histological subtypes of non-Hodgkin's lymphoma and has also identified some new correlations which may prove useful in the investigation of the biological basis of the disease.

The case index of the Cancer Institute of Victoria (Australia) contained 19 cases of adenocarcinoma of the nose and paranasal sinuses. Eighteen of the cases were in men and 1 in a women. Routine questioning of these patients revealed an occupation involving woodworking in 7 cases, whereas among 80 cases of other malignant tumors of the nose and sinuses there were only 4 who had been woodworkers. Among the patients with adenocarcinoma of the nose and sinuses, there was a significantly higher proportion of woodworkers than in the general population. The findings are consistent with European reports associating nasal adenocarcinoma with wood dust, but whereas the workers at risk in Europe are mainly in the furniture industry, some of the workers affected in Victoria have been sawmillers or carpenters. The specific salivary patterns of tumors of mucous glands are not associated with woodworking.

Summary Initial classifications of 1009 testicular tumours were reviewed as part of a population based survey of all testicular neoplasms in Victoria, Australia, between 1950 and 1978. All reviews were made by one of two pathologists at the Peter MacCallum Cancer Institute, using the system of the British Testicular Tumour Panel. Accuracy of diagnosis varied markedly over the time period and with pathological category. Seven cases were initially designated malignancies but were determined to be non-malignant conditions upon review. In each decade, review reduced the proportion of seminomas and increased the proportion of non-seminoma germ cell tumours (NSGCT) and non germ cell tumours. Reclassification resulted in changed age specific incidences of seminoma and NSGCT, most noticeably in 1950-59. Trends in age standardised incidence of seminoma and NSGCT were not affected by reclassification although the values were. The trend in age standardised incidence of non germ cell tumours was affected by reclassification. The implications of the changes in classification for epidemiological studies and clinical management are discussed.

The examination of sequential karyotypes in hematologic disorders has demonstrated that karyotypic changes are often associated with concurrent changes in clinical behavior. Acquired abnormalities that recur among different patients may also suggest genomic areas important to tumor progression. We therefore examined sequential karyotypes in 21 patients with non-Hodgkin lymphoma (NHL). Sixteen of the 21 karyotypes demonstrated changes, including the majority of 6 small lymphocytic, 11 follicular, and 4 intermediate and high-grade diffuse lymphomas. The t(14;18)(q32;q21) occurred in ten initial karyotypes was retained in all cases. The band most frequently affected by newly acquired abnormalities was 14q32 (n = 5); chromosomes 1 and 2 (n = 5, each), and the 17p arm (n = 4) were also commonly affected. The acquired deletion of all or part of 17p appeared to be associated with a poor prognosis. Histologic transformation and karyotypic change did not correlate. This study of sequential karyotypes in NHL 1) confirms the primary importance of the t(14;18), 2) suggests that the 14q32 band is involved frequently in both primary and secondary cytogenetic events, and 3) suggests other genomic regions of potential significance to progression.