Perplexing pigmented papules simulating malignant melanoma

The clinical presentation of irregularly pigmented papules raises a spectrum of diagnostic possibilities. An eighty-five-year-old black man was referred for evaluation of lesions of fifty years' duration. The lesions were 1 to 2 cm hyperkeratotic, irregularly darkly-pigmented papules limited to sun-exposed areas. The histopathologic findings of large keratinocytes, acanthosis, hypergranulosis, and orthokeratosis were compatible with a diagnosis of large cell acanthoma. We believe large cell acanthoma should be included in the differential diagnosis of keratotic or irregularly pigmented lesions on sun-exposed skin, even in black patients.     

Dermatoscopy for melanoma and pigmented lesions

This article presents an overview of the history and development of dermatoscopy over the last 2 decades. The common dermatoscopic diagnostic algorithms are discussed, including classic pattern analysis, the ABCD rule (asymmetry, border, color, and dermatoscopic structures), 7-point checklist, and Menzies method, as well as a new method by the authors (ASAP: a simple and practical approach). In addition, evidence on the clinical impact and challenges of dermatoscopy for the diagnosis and management of pigmented lesions and the importance of training are reviewed.     

Paradigmatic cases of pigmented lesions: How to not miss melanoma

A large number of cases of melanoma exhibit clinical and dermoscopic clues leading to the correct diagnosis; however, sometimes melanoma can mimic benign melanocytic and non‐melanocytic lesions. We present a small series of melanomas in which additional clues provided by confocal microscopy increased the index of suspicion and prompted us to perform an excisional biopsy. Practical rules that are useful in difficult‐to‐diagnose melanomas are discussed.     

The risk for cutaneous malignant melanoma, melanoma in situ and intraocular malignant melanoma in relation to tobacco use and body mass index

BACKGROUND: The incidence of cutaneous malignant melanoma (CMM) and melanoma in situ (MIS) has been increasing during the last 50 years. Malignant melanoma (MM) is also the most common intraocular malignancy (IMM). Besides ultraviolet radiation, the cause of these tumours is largely unknown. OBJECTIVES: We designed a study to examine the effect of body mass index (BMI) and tobacco use on the risk for MM and MIS. METHODS: Analyses were performed on a nationwide cohort of 339 802 Swedish construction workers. Exposure information was collected prospectively by questionnaires combined with personal interviews. RESULTS: Follow up yielded a total of 7 663 400 person-years during which 1639 workers developed MM/MIS. The risk for MM/MIS was reduced in current or previous smokers compared with those who had never smoked, both when analysing all smoking tobacco products combined and when analysing cigarette and pipe smokers separately. The risk was further diminished with longer duration of smoking and greater quantity of tobacco smoked. The effect was more evident in CMM/MIS than in IMM. Snuff taking conferred a decreased risk for CMM/MIS, and a BMI over normal weight range conferred an increased risk for CMM. CONCLUSIONS: Tobacco smoking was found to be inversely associated with the risk for CMM and MIS. The mechanism of action is unknown but it has been suggested to be due to the immune suppressive effect that tobacco exerts which would be protective against deleterious immune reactions caused by, for example, the sun. Neither is the mechanism behind the higher risk for CMM due to being overweight known. One hypothesis is that it is an effect of a hormonal imbalance. Further studies are required to elucidate these mechanisms.     

Cervical lesions in patients with malignant melanoma

Koilocytes were found in the cervical epithelium in association with cervical intra-epithelial neoplasia in 8 out of 9 cases of malignant melanoma. This suggests that the cervical lesion in them was of viral origin. In 62 women with malignant melanoma but without cervical atypia there was also an excess of koilocytosis compared with controls with neither lesion. These findings point to the possibility that human papilloma virus infection may also be involved in the development of malignant melanoma, as it has been shown to be in cervical intra-epithelial neoplasia.     

Oral melanoma and other pigmented lesions of the oral cavity

This article presents a review of oral malignant melanoma and other oral cavity pigmented lesions. The dismal prognosis for patients with oral malignant melanoma is partly due to patients' delayed recognition of signs of early disease and delayed diagnosis by physicians. Pigmented macules and plaques in the oral cavity, representing the radial growth phase of tumors, often go unrecognized for months or years before tumor invasion. Therefore, if early detection of thin oral melanomas is to be achieved, all pigmented oral cavity lesions should be viewed with suspicion. Biopsies of such lesions are indicated when the clinical diagnosis is uncertain. Prompt aggressive surgical treatment is essential in reducing the morbidity and mortality from oral melanomas. The differential diagnosis of oral melanomas includes nevi, oral melanotic macules, amalgam tattoos, Kaposi's sarcoma, oral melanoacanthoma, and physiologic pigmentation.     

Differentiation of common benign pigmented skin lesions from melanoma by high-resolution ultrasound

BACKGROUND: There are potential clinical benefits if non-invasive methods can be used to diagnose or exclude melanoma. OBJECTIVES: We investigated high-resolution ultrasound (HRU) as a potential non-invasive diagnostic aid for pigmented skin lesions. METHODS: Using a 20-MHz ultrasound B-scan imaging system interfaced to a computer, we assessed acoustic shadowing and entry echo line enhancement (EEE) for 29 basal cell papillomas (BCPs) and 25 melanomas. Acoustic shadowing was estimated by the dermal echogenicity ratio (DER), comparing mean echogenicity below the lesion with that of adjacent dermis. Histological features were scored independently. RESULTS: DER < 3 correctly distinguished melanoma from BCP with 100% sensitivity and 79% specificity. Specificity increased to 93% if the presence of EEE was included as a discriminator. Shadowing correlated most significantly with histological extent of hyperkeratosis (P < 0.0001). Consequently, this method falsely identified non-keratotic acanthotic BCP (n = 3) as melanoma. Highly significant differences between benign naevi (n = 15) and melanomas (n = 24) were found. The SD of retrolesional echogenicity was higher for naevi than melanomas (P < 0.0001), but such an analysis was poorly specific for the diagnosis of melanoma (30%). CONCLUSIONS: Overall, HRU has considerable potential as a high-performance screening tool to assist in the discrimination between BCP, but not benign naevi, and melanoma. In particular, it may be possible to exclude melanoma with 100% certainty in the differentiation of BCP from melanoma.     

Pre-diagnostic digital imaging prediction model to discriminate between malignant melanoma and benign pigmented skin lesion

Background: Malignant cutaneous melanoma is the most deadly form of skin cancer with an increasing incidence over the past decades. The final diagnosis provided is typically based on a biopsy of the skin lesion under consideration. To assist the naked-eye examination and decision on whether or not a biopsy is necessary, digital image processing techniques provide promising results.
Hypothesis and aims: The hypothesis of this study was that a computer-aided assessment tool could assist the evaluation of a pigmented skin lesion. Hence, the overall aim was to discriminate between malignant and benign pigmented skin lesions using digital image processing.
Methods: Discriminating algorithms utilizing novel well-established morphological operations and methods were constructed. The algorithms were implemented utilizing graphical programming (LabVIEW Vision). Verification was performed with reference to an image database consisting of 97 pigmented skin lesion pictures of various resolutions and light distributions. The outcome of the algorithms was analysed statistically with MATLAB and a prediction model was constructed.
Results/Conclusion: The prediction model evaluates pigmented skin lesions with regards to the overall shape, border and colour distribution with a total of nine different discriminating parameters. The prediction model outputs an index score, and by using the optimal threshold value, a diagnostic accuracy of 77% in discriminating between malignant and benign skin lesions was obtained. This is an improvement compared with the naked-eye analysis performed by professionals, rendering the system a significant assistance in detecting malignant cutaneous melanoma.     

Educating patients about malignant melanoma: computer-assisted learning in a pigmented lesion clinic

This prospective controlled study aimed to evaluate the effectiveness and acceptability of a computer program (CAL) designed to educate patients about skin protection including signs of melanoma. Two hundred and twenty-seven patients were recruited either from the Pigmented Lesion Clinic (PLC) or the Orthopaedic Fracture Clinic (OFC). A baseline measure of anxiety was obtained and subjects were allocated to either non-interactive, interactive or control conditions. Measures of anxiety and knowledge about malignant melanoma and skin protection were obtained prior to discharge from the clinic and knowledge was assessed again at 1-week follow-up. Results indicate that, although anxiety in the PLC subjects decreased significantly more than in the OFC patients, there was no significant effect of intervention. There was a significant effect of intervention on knowledge (F = 81.06, d.f. 2, 218, P < 0.0001) with participants having better knowledge on leaving the clinic in the interactive CAL condition than in both the Non-interactive condition and control. Non-interactive CAL was associated with higher knowledge than control. Knowledge gains were maintained at 1-week follow-up.     

色素痣和恶性黑素瘤组织及A375细胞中色素上皮衍生因子的表达

目的 探讨色素上皮衍生因子(PEDF)在色素痣和恶性黑素瘤组织及A375细胞中的表达及其意义.方法 用免疫组化法检测正常人皮肤组织、正常人色素痣以及恶性黑素瘤组织中PEDF的表达与分布.用蛋白印迹法检测正常黑素细胞及恶性黑素瘤细胞株A375中PEDF的表达与分布.用RTPCR法检测正常黑素细胞及A375中PEDF mRNA的表达.结果 ①PEDF在正常皮肤组织、正常人色素痣及恶性黑素瘤组织中的表达逐渐降低,三组间差异有统计学意义(P<0.05).②PEDF在正常黑素细胞中表达,而在恶性黑素瘤细胞株缺失.③PEDF mRNA在恶性黑素瘤细胞中的表达量明显低于正常黑素细胞.结论 PEDF的表达降低在恶性黑素瘤的发病机制中可能起一定作用.     

Dermatoscopy of pigmented lesions

Dermoscopy is a simple to use in vivo method for the early diagnosis of malignant melanoma and the differential diagnosis of pigmented skin lesions. It has been shown to increase diagnostic accuracy over clinical visual inspection in the hands of an experienced physician. This paper is a review of the principles of Dermoscopy as well as recent technological developments.