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Biomedical subjects

J K Rivers

Publications and source records attributed to J K Rivers.

At least 37 records · Page 2Linked to original sources

Cutaneous melanomas that defy conventional prognostic indicators.

Tumor thickness is usually an accurate prognostic indicator for the patient with melanoma. However, very thin primary melanomas occasionally recur locally or metastasize, whereas some patients with very thick primary melanomas survive far longer than expected. There is also a group of patients with primary melanomas of various thicknesses who relapse after a very long disease-free interval. The large database of the Sydney Melanoma Unit which now contains comprehensive long-term follow-up on more than 13,000 patients treated over a 45-year period, has provided a unique opportunity to study melanomas that defy conventional prognostic indicators. Recurrence developed in 2.8% of melanoma patients classified as stage I (pTNM staging system) and with very thin lesions (< 0.50 mm). These recurrences developed more frequently in women than men and histologically were found to be associated with ulceration, high mitotic activity, and invasion to Clark's level IV, but not with regression. Concurrent lymph node metastases (stage III) were present in 3.1% of patients with very thin lesions (< 0.50 mm). In this group, most patients were men, and every lesion displayed regression. Total survival exceeded 15 years in 15.7% of stage II and III patients with very thick lesions (> 5.5 mm). In 1.7% of patients with lesions of any thickness, the disease-free interval before relapse was > 15 years. Neither in patients with very thick lesions surviving for > 15 years, nor in those with a disease-free interval of > 15 years was it consistently possible to show the presence or absence of any of the histological features usually considered to be of prognostic significance.

Adult↗

Public education projects in skin cancer. Experience of the Canadian Dermatology Association.

The mandate of the Canadian Dermatology Association's Sun Awareness Program is to increase awareness of the dangers of the sun's ultraviolet (UV) rays and to provide information on prevention and early detection of skin cancer. Major projects include an annual national press campaign, which reaches an increasing number of Canadians each year, and the production and distribution of educational materials. Each year during Sun Awareness Week, screening stations have been established across the country, staffed by volunteer dermatologists and members of the Canadian Cancer Society. In Vancouver between 1991 and 1993, 1767 people were screened for skin cancer. Results indicate that these events can attract people at risk for skin cancer, even though people older than age 65 are probably underrepresented as a group. Although popular with the public, these screenings are difficult to organize and are limited by human resources. These events continue in limited numbers, because they provide an excellent venue for the dissemination of educational material. Cooperation with federal agencies has been a major focus of the program. For the past 2 years, educational material on protecting newborns and children from the sun has been made available free to every new mother in Canada, while Environment Canada's Ultraviolet index program provides daily information on UV intensity along with public health messages. With the realization that health promotion requires a sustained change in behavior of an individual, we are now embarking on a national program to evaluate the knowledge, attitudes, and behavior of Canadians concerning UV radiation. With this information, we hope to adapt our educational materials so that people will adopt and maintain healthy behavior choices while out in the sun.

Adolescent↗

The eastern Australian childhood nevus study: prevalence of atypical nevi, congenital nevus-like nevi, and other pigmented lesions.

BACKGROUND: Various melanocytic lesions are frequently observed. An understanding of phenotypic factors and environmental stimuli that are associated with these lesions may help explain their pathogenesis. OBJECTIVE: This study was undertaken to determine the prevalence of atypical nevi, blue nevi, cafe-au-lait macules, congenital nevus-like nevi, halo nevi, nevi spili, nevi 5 mm or more in diameter, and skin-colored melanocytic nevi in a population of schoolchildren and to explore risk factors including solar radiation in the development of these melanocytic lesions. METHODS: A cross-sectional study was performed by the same medical investigators to examine schoolchildren in three Australian cities that span a wide range of latitudes. RESULTS: Data from 1123 white Australian schoolchildren, 6 to 15 years of age, were analyzed. Acquired melanocytic nevi (atypical nevi, nevi > or = 5 mm in diameter, and skin-colored nevi) were more likely to develop in older fair-skinned subjects who had freckles and lived closest to the equator. Café-au-lait macules and congenital nevus-like nevi were observed in 36.3% and 4.4% of the total population, respectively. Prevalence for both these types of melanocytic lesions increased significantly with decreasing latitude. Halo nevi were present in 5.3% of the subjects and were usually solitary. These lesions were related to the presence of atypical nevi primarily by virtue of their size rather than of other features of clinical atypia. CONCLUSION: Like melanocytic nevi in general, large and atypical nevi are strongly influenced by geographic location and, by implication, degree of solar radiation. The same can be said for congenital nevus-like nevi, which suggests that many so-called congenital nevi are in fact acquired early in life.

Adolescent↗

Eosinophilic ulcer of the oral mucosa.

BACKGROUND: The eosinophilic ulcer is a rare lesion of the oral mucosa that has been infrequently described in the literature. OBJECTIVE: We attempted to characterize the history, demographics, clinical features, histologic features, pathogenesis, and treatment of the eosinophilic ulcer. METHODS: We observed three new cases of eosinophilic ulcer and reviewed the English-language literature. RESULTS: Eosinophilic ulcer occurs in any age group, without sex preference. The most common site in the oral cavity is the tongue, and the average size at diagnosis is 1.6 cm2. These lesions are often ulcerated, may be tender, and are sometimes multiple. The histologic features are characteristic but likely represent a spectrum of related disorders. Most eosinophilic ulcers will resolve spontaneously within a month. Recurrences are uncommon (< 15%). CONCLUSION: The eosinophilic ulcer is a benign, self-limited, reactive process of the oral mucosa of unknown origin. Its histologic features are characteristic but may be confused with atypical histiocytic granuloma and angiolymphoid hyperplasia with eosinophilia or, more importantly, lymphoma. This condition most likely represents a spectrum of related disorders with overlapping clinical and histologic features. After the diagnosis has been histologically confirmed, conservative management is suggested.

Adolescent↗

Sinonasal malignant melanoma--a clinicopathologic analysis of 18 cases.

Sinonasal melanoma is a rare malignancy. We present the clinicopathologic review of 18 cases seen at the British Columbia Cancer Agency between 1976 and 1992: 13 men and five women, mean age 66 years (range 32-88). Patients presented with nasal obstruction and bleeding (n = 8), obstruction alone (n = 4), bleeding alone (n = 5) or pain (n = 1). Those with bleeding presented with a shorter duration of symptoms than those with obstruction alone. All patients with obstruction alone died of their disease, while all patients with bleeding alone are alive or have died of an unrelated cause; four out of eight patients with both obstruction and bleeding are alive. There was no significant relationship between treatment modality and outcome. Histologic subtypes included epithelioid (n = 10), spindle-cell (n = 4), small-cell (n = 3) and pleomorphic (n = 1). Eight out of 11 cases from whom samples of paraffin-embedded tissue were available showed more prominent staining for HMB-45 than for S-100. In two cases, only rare (< 0.1%) cells stained for S-100. Cell type, mitotic rate and P53 expression were unrelated to disease outcome. Six out of seven patients with < or = 10% of cells showing intense staining for PCNA were alive or had died of an unrelated cause, while three out of four with > 10% staining died of their disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Localized chrysiasis induced by laser therapy.

BACKGROUND: Chrysiasis is a rare blue-gray skin discoloration that occurs in sun-exposed sites of some patients who receive gold salts. A unique case of localized chrysiasis developed immediately after Q-switched ruby laser (694 nm) irradiation for postinflammatory hyperpigmentation secondary to granuloma faciale in a patient who was receiving long-term gold sodium thiomalate therapy for psoriatic arthritis. Skin biopsy specimens showed striking changes in the ultrastructural characteristics of cutaneous gold deposits following laser treatment. OBSERVATIONS: A blue-gray skin discoloration developed immediately after laser exposure and persisted unchanged after 1 year. Transmission electron microscopy of skin biopsy specimens showed electron-dense gold deposits. Before laser irradiation, these deposits were 106 +/- 35 (mean +/- SD) nm in diameter and faceted, consistent with a crystalline structure. Posttreatment deposits were round, smaller, measured 16 +/- 4 nm, and resembled colloidal gold. Identical findings were observed in an area of sun-protected skin treated with the Q-switched ruby laser; irradiation with a pulsed dye laser at 585 nm had no effect. CONCLUSIONS: Localized chrysiasis was induced in a patient receiving parenteral gold therapy who underwent treatment with a Q-switched ruby laser. This form of chrysiasis resulted from a structural alteration in dermal gold deposits. A similar physiochemical modification in gold deposits induced by UV light may explain the localization of chrysiasis to sun-exposed skin in affected patients.

Arthritis, Psoriatic↗

Sunlight: a major factor associated with the development of melanocytic nevi in Australian schoolchildren.

BACKGROUND: Case-control studies have identified melanocytic nevi (MN) as the most important phenotypic risk factor for melanoma. A knowledge of any environmental factors that cause MN may facilitate prevention of melanoma. OBJECTIVE: This study was undertaken to explore the possible role of ambient solar irradiation in the development of MN in children. METHODS: With a standard protocol developed after international consultation, the same medical observers examined children in three Australian cities (Melbourne, Sydney, and Townsville) that span a wide range of latitude. RESULTS: A total of 1123 Australian schoolchildren 6, 9, 12, and 15 years of age were surveyed. Larger numbers of MN were found (mean 65.4 MN, standard deviation 52.9) than in previous studies of children. Prevalence increased with diminishing latitude (51.1 in Melbourne, 66.5 in Sydney and 77.2 in Townsville), particularly in children 6 and 9 years of age. Although nevus numbers were higher in children with light skin and hair, blue eyes, and freckling, the latitude gradient remained after adjustment for these and other factors in multivariate analysis. CONCLUSION: Latitude of residence, and by implication ambient UV radiation, is strongly related to nevus prevalence in young Australian children. However, these differences diminish with age and may disappear by 15 years of age.

Adolescent↗

Management of precursors and primary lesions of melanoma.

A better understanding of the natural history of pigmented lesions has recently led to a more conservative surgical approach to the management of certain congenital, dysplastic, and other acquired melanocytic nevi. The treatment of primary melanoma is still based almost exclusively on the thickness of the primary lesion. Recent data showed that a surgical margin of 1 cm is appropriate treatment of most thin melanomas (1 mm or less in Breslow thickness), whereas thicker lesions may be removed with a surgical margin of 2 to 3 cm without adversely affecting the rate of local recurrence or patient survival. These recommendations are guidelines only and may be modified by the anatomic site and histologic subtype of tumor. The value of prophylactic lymph node dissection in the management of primary melanoma is still debated and awaits the results of randomized, prospective studies.

Dysplastic Nevus Syndrome↗

Acute monocytic leukaemia in a HIV-seropositive man.

Individuals infected with the human immunodeficiency virus (HIV) have been reported to develop a number of malignant neoplasms. We recently treated an HIV patient who had acute monocytic leukaemia which was first evident in the skin. To our knowledge, this is the first report of a case of acute monocytic leukaemia occurring in a HIV-infected person.

Facial Neoplasms↗

The coexistence of lymphangiosarcoma and Kaposi's sarcoma in a renal transplant recipient.

A case of coexisting lymphangiosarcoma and Kaposi's sarcoma that occurred in a female renal transplant recipient is presented. Both sarcomas were localized to the skin and were slowly progressive over several years. The coexistence of these two sarcomas may indicate that they arose from a common precursor endothelial cell and that systemic immune suppression may be important in the pathogenesis of both these malignancies.

Female↗

Erythema multiforme after contact dermatitis in response to an epoxy sealant.

A case of erythema multiforme associated with an allergic contact dermatitis in response to an epoxy-based compound is presented. Patch tests revealed a positive reaction to both the epoxy resin and the hardener. Chemicals applied directly to the skin should be considered as a potential cause of erythema multiforme.

Arm↗

Melanocytic nevus density in Asian, Indo-Pakistani, and white children: the Vancouver Mole Study.

Melanocytic nevus density in 378 Asian and 68 Indo-Pakistani school children 6 to 18 years of age was compared with that in 1146 white children of the same age range. At all ages, the number of melanocytic nevi 2 mm or larger per square meter of body surface area was substantially lower in Asians and Indo-Pakistanis than in white persons. Among white persons characteristics associated with a higher risk of cutaneous melanoma in adults, that is, light skin color, a propensity to burn rather than tan in the sun, and a history of numerous or severe sunburns, are also associated with the highest melanocytic nevus density in children. Examination of these same host pigmentation and sunburn factors among Asian children revealed no association with nevus density.

Adolescent↗