Melanoma in Western Australia 1975-76 to 1980-81: trends in demographic and pathological characteristics

Trends in incidence rates of cutaneous malignant melanoma in Western Australia from 1975-76 to 1980-1981 have been examined with reference to age, sex, body site, presence or absence of dermal invasion, tumour thickness, histological type, socioeconomic status and occupation. The incidence rates of all melanomas increased from 22.1 to 31.5 per 100,000 person-years in males and from 23.6 to 28.6 in females. In males, the relative annual increase in the incidence of invasive melanoma was 2.2%, and in females it was 5.6%. In-situ melanomas had larger relative increases in incidence (28% per annum in males and 10% in females) and the thickness of invasive lesions decreased between 1975-76 and 1980-81. The relative increase in incidence of invasive melanomas was greatest on the body sites with the highest rates initially--the trunk in males and the lower limbs in females. There was an increase in the proportion of invasive lesions classified as superficial spreading melanoma. The increase in incidence of in situ melanomas was largely restricted to the head and neck in older men of high socioeconomic status resident in Perth. This trend in in-situ melanoma was mainly due to an increase in the recorded incidence of Hutchinson's melanotic freckle. It may have been, in part, an artefact due to increased recognition of Hutchinson's melanotic freckle in this sub-group of the population.

Strongyloides stercoralis infections in the muscles of mice: a model for investigating the systemic phase of strongyloidiasis

The sequence of events following infection of mice with the intestinal nematode, Strongyloides stercoralis, has been observed. Most infective larvae passed to the muscles where they did not develop further. In mice given primary infections, larvae were found in muscles for the first 9 d or so, then disappeared spontaneously. This was associated with an inflammatory reaction, predominantly eosinophilic and histiocytic in nature, around dying larvae. In mice exposed to the worms previously, both inflammation and worm destruction were hastened indicating the acquisition of resistance. A number of immunological parameters were measured in both primary and challenge infections. Specific antibodies of the IgM and IgG classes appeared, a marked immediate hypersensitivity reaction to injected antigen developed, and a transient blood eosinophilia occurred. No effects on phytohemagglutinin-induced spleen cell transformation were discerned, nor was transformation induced by specific antigen. It is concluded that this system provides a potentially useful model for investigating the systemic phase of strongyloidiasis, particularly with respect to assessing anthelmintic efficacy and the functions of fractionated antigens.

Kinetics of cells in the intestinal mucosa of mice following oral infection with Ancylostoma ceylanicum

A variety of cell types in the intestinal mucosa of mice has been observed following oral infection with Ancylostoma ceylanicum and the changes in their numbers quantified. The number of lamina propria mast cells increased following infection and reached a peak at 4 days; by 21 days the numbers had returned to normal levels. Globule leucocytes displayed a similar marked response but the numbers returned to within normal limits 7 days after infection. Granular intraepithelial lymphocytes did not alter significantly during the period of observation whereas non-granular intraepithelial lymphocytes declined in numbers following infection and were significantly decreased by 3 weeks. Goblets cells showed a similar response to infection as lamina propria mast cells and reached a peak level at 4 days. Following initial fluctuations in eosinophil numbers there was a substantial increase in the numbers of these cells with peak levels being reached at 21 days; eosinophil numbers then remained elevated for the duration of observation. Partial villous atrophy was seen 4 days after the arrival of larvae in the small intestine with maximum reduction in the length of villi at 7 days. Thereafter, there was a return to normal length followed by a significant elongation in villus length 28 days after infection. The influences of these various cell types on the expulsion of intestinal parasites are discussed.

Surgical treatment and survival from cutaneous malignant melanoma

Varied methods of primary surgical treatment of 189 cases of cutaneous malignant melanoma studied in Western Australia had no statistically significant effect on prognosis. The results indicate that wide excision is not justified as the standard treatment of cutaneous malignant melanoma.

Cutaneous malignant melanoma and fluorescent lighting

A population-based case-control study of cutaneous malignant melanoma occurring during 1980-81 was conducted in Perth, Western Australia. Three hundred and thirty-seven cases and 349 matched controls were reinterviewed in 1983 with regard to their fluorescent light exposure. The incidence rate of all melanomas was not associated with rate of exposure or cumulative exposure to all fluorescent lights or just those without diffusers. Separate analyses by histogenetic type and, where possible, body site of melanoma showed, in most instances, no consistent association between incidence rate of melanoma and exposure to fluorescent lights without diffusers. Incidence of melanomas of unclassifiable histogenetic type, however, increased with increasing duration of exposure (P-value for trend .02). This association was weaker and the P-value higher (.11) when exposure was considered only in residential rooms and offices, where light fittings are closest to the subject. Adjustment for the effects of total and intermittent sun exposure on melanoma rates did not alter the above trends appreciably.

Cutaneous malignant melanoma in western Australia

The first detailed epidemiological and histological studies of cutaneous malignant melanoma in Western Australia have been undertaken recently. High and, apparently, increasing annual incidence rates have been confirmed (1975/76: 23.0/100 000 in males, 25.0/100 000 in females. 1980/81: 28.9/100 000 in males, 31.5/100 000 in females--rates for pre-invasive and invasive lesions combined). The results support a causal relationship of sunlight exposure with cutaneous melanoma in general, while suggesting that melanoma of Hutchinson's melanotic freckle type is related to continuous sun exposure whereas intermittent exposure is more important in the etiology of melanoma of superficial spreading type. The proposed etiological heterogeneity of melanoma and the dual origin theory of Mishima have been embodied in a theory of the etiology and histogenesis of melanoma which proposes that nodular melanoma is a common end result of the other types of melanoma rather than a distinct histogenetic entity. Some components of this theory have been supported by results of the 1980/81 West Australian Lions Melanoma Research Project. The overriding importance of tumour thickness as the most accurate histologic index of prognosis yet available has been emphasized by correlation with survival rates in Western Australia and the Oxford Region. Tumour thickness has also been shown to be the most reproducible of histological features, while others were subject to considerable interobserver variation. The better prognosis for melanoma patients in Western Australia compared with low incidence regions, when correlated with tumour thickness, indicated that melanoma is diagnosed earlier in areas of high incidence due to greater awareness of the risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Cutaneous malignant melanoma in women: exogenous sex hormones and reproductive factors

The roles of exogenous sex hormones and reproductive factors in the causation of malignant melanoma of the skin in women were examined in a case-control study of 276 patients and 276 matched controls in Western Australia. There was no consistent evidence of a relationship between the incidence rates of different histogenetic types of melanoma and age at menarche, duration of menstrual life, degree of obesity, number of pregnancies more than 20 weeks in duration or use of oral contraceptive preparations (OCP). Exposure to OCP was examined separately for different age periods and in different intervals of time before diagnosis; no consistent trend emerged. There was borderline evidence of an association of superficial spreading melanoma with duration of use of unopposed oestrogens. On the basis of seven studies of the relationship of melanoma to OCP published to date, we estimate that the total incidence rate of melanoma in OCP ever-users is unlikely to be increased by more than one third the rate in never-users.

Inter-observer variation between pathologists in the classification of cutaneous malignant melanoma in western Australia

Inter-observer variation between six pathologists in their application of histological classifications during a survey of cutaneous malignant melanoma was analysed using kappa statistics. The highest levels of adjusted agreement were attained for tumour thickness and the presence of ulceration; intermediate levels were achieved on cross-sectional profile, level of invasion, histogenetic type, solar elastosis and the presence of an associated benign melanocytic lesion; agreement on other histological features of melanoma tended to be relatively poor. The problems experienced in the interpretation of these classifications are discussed and suggestions for their improvement are offered.

Survival from preinvasive and invasive malignant melanoma in Western Australia

The crude and relative survival rates from malignant melanoma of the skin were evaluated in 528 patients diagnosed in Western Australia in 1975-1976. Follow-up of patients to December 31, 1980 was 96% complete. For invasive malignant melanoma the relative five-year survival rates were 85% in men and 89% in women, while in cases of preinvasive melanoma both sexes experienced 100% relative five-year survival. The effects on prognosis of sex, anatomic site, clinical stage, level of invasion and tumor thickness were examined. Invasive melanomas of less than 0.76 mm in thickness also were associated with 100% relative survival. The variation in survival of melanoma patients with geographic location and the relative contributions of early diagnosis and biologic nature to the favorable outcome of melanoma in Australia are discussed.

Survival from invasive cutaneous malignant melanoma in Western Australia and the Oxford Region: a comparative histological study of high and low incidence populations

A detailed histological review of 196 cases of invasive cutaneous malignant melanoma diagnosed in Western Australia, a high incidence area, during 1975-76 and of 226 cases during the period 1972-76 from the Oxford Region, a low incidence area, was made by one pathologist using the same parameters for each series. Five-year survival rates were analysed with respect to histological features, sex and site, with and without correction for tumour thickness. The results showed higher overall survival rates in Western Australia, with marked differences in prognosis between males and females in the Oxford Region, and between Oxford males and patients of both sexes in Western Australia. These findings were in accord with the corresponding differences in tumour thickness, and they support the theory that survival rates from cutaneous malignant melanoma are higher in areas of high incidence because they are diagnosed and treated earlier.

Seasonal variation in the junctional component of pigmented naevi

From an assessment of the presence of a junctional component in 8,380 pigmented naevi, and histological review of its extent and the presence of inflammation and regression in a sample of 216 junctional and compound naevi, it was determined that naevi excised in summer were more likely to have a junctional component and evidence of inflammatory response than those excised in winter. It is suggested that a short-term promotional effect of sunlight on cells in the junctional zone of pigmented naevi may, in addition to increased case ascertainment in summer, explain reported seasonal variation in the incidence of malignant melanoma.

A histological comparison of cutaneous malignant melanoma between the Oxford Region and Western Australia

Two series of cutaneous malignant melanoma (CMM), one from a low incidence area (the Oxford Region) and one from a high incidence area (Western Australia), were compared by one pathologist using the same histological criteria. The findings included similarities in the distributions of histogenetic type of CMM, predominant cell type, and the degree and pattern of inflammatory reaction. Differences were found in other features including tumour profile, the presence of ulceration, mitotic activity, evidence of regression and level of invasion. The most important, and consistent morphological difference was the greater thickness of tumours from the Oxford Region, which is thought to be consistent with the theory that CMM is diagnosed at an earlier stage in high incidence areas because of greater medical and public awareness of the condition. Some problems in the use of accepted classifications of CMM are discussed.

An improved method of analysis of observer variation between pathologists

An improved method of analysing interobserver variation in histopathological studies is described and illustrated, by use of data from a congruence survey of malignant melanoma. The method provides, between any number of pathologists, an assessment of overall agreement and of agreement on each individual category of a classification system. Adjustment for differences in chance agreement due to varying numbers of categories or an altered composition of cases is included in the analysis. A generalization of the procedure designed to measure the strength of associations between different categories is formulated and explained with the use of an example.

Cryptococcosis with multiple squamous cell tumors associated with a T-cell defect

A 54-year-old male with multiple squamous cell tumors was shown to have capsule deficient cryptococcosis confined to bone. Further investigations revealed a severe defect of cell-mediated immunity and the presence of serum antinuclear factor. An underlying T-cell defect might explain the unusual cryptococcal infection and the extremely aggressive behavior of the skin tumors.

Collision carcinoma at the esophagogastric junction: report of two cases

Two cases of colliding gastric adenocarcinoma and esophageal squamous cell carcinoma are presented. The occurrence of carcinomas of mixed histological type at the esophagogastric junction is uncommon, collision carcinomas being particularly rare. Criteria and problems in the diagnosis of mixed carcinomas are reviewed and discussed. It is suggested that, although undoubtedly uncommon, collision carcinomas at this site may occur more frequently than previously reported.

Transient acantholytic dermatosis

A series of twenty-four cases of transient acantholytic dermatosis (TAD) is presented. All patients were male and their eruptions tended to be more persistent than those of previously reported cases. The epidermal changes included four patterns of acantholysis, of which the pemphigus-like pattern was associated with the more persistent eruptions. Although twenty-three of the twenty-four patients had other actinic-associated skin lesions, no direct relationship between the onset of TAD and episodes of excessive sun exposure was found. Oral vitamin A treatment has been effective in some cases.

Disseminated intravascular thrombosis as the cause of ischaemic enterocolitis

Disseminated intravascular thrombosis was diagnosed in a woman aged 63 years. At autopsy the typical appearances of ischaemic enterocolitis were found, together with thrombi in other organs. This case illustrates the previously postulated connection between intravascular thrombosis and ischaemic enterocolitis.

Waldenström's disease of the jejunum

A case of Waldenströms macroglobulinaemia with characteristic clinical features was investigated in life and at autopsy. Using immunochemical and immunohistochemical methods it was confirmed that the abnormal clone of cells producing IgM formed a solitary tumour in the jejunum causing partial obstruction. Resection of the tumour led to an improvement in the clinical condition and biochemical measurements.

Malakoplakia of the prostate: a morphological and biochemical study

A case of malakoplakia of the prostate is presented. Electron microscopic appearances support the origin of the Michaelis-Gutmann bodies from phagolysosomes in the histiocytes characteristic of the lesion. Biochemical analysis revealed the presence of muramic acid in the prostate with malakoplakia. This amino sugar is characteristic of bacterial cell walls and despite the absence of demonstrable bacteria in the affected tissues indicates the involvement of bacteria in the disease process.

Atrophic gastritis in gastrectomy specimens

Examination of gastrectomy specimens has shown that atrophic gastritis and intestinal metaplasia are widespread and have the same distribution in cancer of the stomach as in gastric ulcer affecting the body. Their distribution is restricted to the distal part of the stomach in pyloric ulcer. After gastrojejunostomy the distribution is also like that seen in cancer. There is a close association of widespread atrophic gastritis and intestinal metaplasia with the development of cancer and a high cancer rate after stomach operation for benign conditions. The similarity of distribution of atrophic gastritis and intestinal metaplasia in the stomach with body ulcer to that in cancer and after gastrojejunostomy points to a higher cancer risk in the stomach containing a body ulcer.

Electron microscopy findings in malignant melanoma of nose

Electron microscopic examination of malignant melanoma tumour tissue taken from a patient who has survived with the tumour without metastases for 13 years has shown spherical melanosomes with no internal fibrillar structure. This finding and other cell features described, suggest that this melanoma developed from Dubreuilh's melanosis rather than melanocytic change in a junctional naevus.