Fatal anaphylaxis following jack jumper ant sting in southern Tasmania.

The "jack jumper" ant (Myrmecia pilosula) is a major cause of anaphylaxis in Tasmania. We describe four deaths attributed to stings by this ant between 1980 and 1999. All victims were men aged 40 years or over with significant comorbidities; two were taking angiotensin-converting enzyme inhibitors, which may increase risk of severe anaphylaxis. Three victims had known ant-sting allergy, but only one carried adrenaline, which he did not use. Another believed he was protected by previous attempts at hyposensitisation with whole ant-body extract. There is potential to prevent deaths by careful education of people with known allergy, prescribing of adrenaline for auto-injection and development of an effective hyposensitisation therapy.

Enigmatic trigeminal sensory neuropathy diagnosed by facial skin biopsy.

Facial paraesthesia due to perineural malignant infiltration is a well recognised complication of basal and squamous cell carcinomas of the head and neck. Perineural involvement was originally attributed to involvement of the perineural lymphatics; however subsequent studies have demonstrated conclusively that these lymphatics do not exist and that the invasion occurs along the line of least resistance. Previous studies on perineural spread of carcinomas of the head and neck have emphasised diagnostic biopsy of an involved nerve (e.g. the infraorbital, mental or major branches of the trigeminal nerve), or at times craniectomy with exploration of the gasserian ganglion. We suggest that in many cases the diagnosis can be obtained by biopsy of the anaesthetic skin alone, without recourse to more involved biopsy techniques. The following case report illustrates this point.

Melanoma in Western Australia in 1980-81: incidence and characteristics of histological types.

All cutaneous malignant melanomas diagnosed in Western Australia in 1980-81 were reviewed and classified according to histological type (i.e., superficial spreading melanoma, Hutchinson's melanotic freckle melanoma (lentigo maligna melanoma), nodular melanoma and melanoma of unclassifiable type). The most common invasive melanoma was superficial spreading melanoma with an incidence rate of 14.3 per 100,000 person-years in females and 9.0 in males. It most commonly affected the trunk in males and the lower limbs in females and showed a peak incidence in middle life. Invasive Hutchinson's melanotic freckle melanoma was much less common than invasive superficial spreading melanoma (1.8 per 100,000 person-years in both sexes), occurred most commonly on the head and neck and increased progressively in incidence with age. Nodular melanomas were more frequent in men (4.5 per 100,000 person-years) than women (2.0). They were thicker than other types of invasive melanomas, showed more mitotic activity and had less evidence of regression. Their site distribution was similar to that of superficial spreading melanoma. In women the pattern of incidence with age was also similar to that of superficial spreading melanoma. In men it was more like that of Hutchinson's melanotic freckle melanoma. Melanomas of unclassifiable type did not have distinctive epidemiological features common to both sexes, although the trunk was the site most commonly affected in both men and women. With some exceptions the patterns of occurrence of in-situ lesions were similar to those of the corresponding invasive lesions. Benign melanocytic naevi were found less often in association with Hutchinson's melanotic freckle (melanoma) (6%) and nodular melanoma (9%) than with superficial spreading melanoma (22%) or melanoma of unclassifiable type (34%).

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.

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.

Inter-observer variation in the histopathological reporting of Hodgkin's disease: an analysis of diagnostic subcomponents using kappa statistics.

Levels of agreement between nine pathologists on the Rye classification of Hodgkin's disease and on diagnostic subcomponents used in applying the classification, were analysed by kappa statistics. Pathologists experienced comparatively little difficulty in agreeing on the presence of nodules and lacunar cells and hence best agreement was achieved on the nodular sclerosis category. Poorer agreement levels on the lymphocytic predominance, mixed cellularity and lymphocytic depletion categories were explained mainly by problems in the assessment of numbers of lymphocytes and abnormal reticulum cells other than Reed-Sternberg cells. Identification of the Reed-Sternberg cell, although of paramount importance to a diagnosis of Hodgkin's disease, appeared to have no great practical relevance to use of the Rye classification in this series of cases.

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.

The Rye classification of a population based series of Hodgkin's disease patients in Western Australia.

Data are presented on the incidence in Western Australia of subtypes of Hodgkin's disease which were obtained by review of all cases of the disease notified between 1960 and 1974. Observations were also made on within- and between-observer agreement on the use of the Rye classification by a group of 9 surgical pathologists, all in the day-to-day practice of pathology. Although many consensus diagnoses were made only after spirited discussion by the Group, the results suggested that general surgical pathologists can perform nearly as well as lymphoma experts. A comparison of the incidence of Hodgkin's disease and distribution of Rye subtypes in Western Australia with 4 other populations showed a similar overall incidence but appreciable variation in the relative frequency of the subtypes--mainly in the proportions of nodular sclerosing and mixed cellularity.