Cliff Rosendahl

Diagnostic accuracy of dermatoscopy for melanocytic and nonmelanocytic pigmented lesions.

BACKGROUND It is unknown whether dermatoscopy improves the diagnostic accuracy for all types of pigmented skin lesions or only for those that are melanocytic. OBJECTIVE We sought to assess if the addition of dermatoscopy to clinical examination with the unaided eye improves diagnostic accuracy for all types of pigmented lesions. METHODS We analyzed 463 consecutively excised pigmented skin lesions collected during a period of 30 months in a primary care skin cancer practice in Queensland, Australia. RESULTS Of 463 lesions, 217 (46.9%) were nonmelanocytic. Overall 30% (n = 138) were malignant including 29 melanomas, 72 basal cell carcinomas, and 37 squamous cell carcinomas. The diagnostic accuracy for malignant neoplasms measured as area under receiver operating characteristic curves was 0.89 with dermatoscopy and 0.83 without it (P < .001). Given a fixed specificity of 80%, the corresponding sensitivity was 82.6% with dermatoscopy and 70.5% without it. The improvement achieved by dermatoscopy was higher for nonmelanocytic lesions than for melanocytic lesions. A short algorithm based on pattern analysis reached a sensitivity of 98.6% for basal cell carcinoma, 86.5% for pigmented squamous cell carcinoma, and 79.3% for melanoma. Among benign conditions, the highest false-positive rate (90.5%) was observed for lichen planus-like keratosis. LIMITATIONS Estimates of diagnostic accuracy are influenced by verification bias. CONCLUSIONS Dermatoscopy improves the diagnostic accuracy for nonmelanocytic lesions. A simple algorithm based on pattern analysis is suitable for the detection of melanoma and nonmelanoma skin cancer.

Dermatoscopy of pigmented Bowen's disease

BACKGROUND Pigmented Bowens disease is not well characterized. OBJECTIVE To characterize the clinical and dermatoscopic appearance of pigmented Bowens disease. METHODS We performed a retrospective analysis of 52 consecutive cases of pigmented Bowens disease. RESULTS Of 951 histopathologically verified cases of Bowens disease that underwent biopsy during the study period, 52 (5.5%) were pigmented. Dermatoscopically pigmented Bowens disease is typified by a pattern of dots and/or structureless zones. In 21.2% (n=11), we observed brown or gray dots arranged in a linear fashion. Vessels were identified in 67.3% of lesions with a predomination of coiled vessels. A linear arrangement of vessels was seen in 11.5%. LIMITATIONS Conclusions are limited by the fact that this was a retrospective, uncontrolled study. CONCLUSIONS Pigmented Bowens disease has a characteristic dermatoscopic pattern. Linear arrangement of brown and/or gray dots and/or coiled vessels is a specific clue to pigmented Bowens disease.

Blue-black rule: A simple dermoscopic clue to recognize pigmented nodular melanoma

Background  Dermoscopy improves melanoma recognition, but most criteria were described in the context of superficial spreading melanoma.

Dermoscopy improves diagnosis of tinea nigra: a study of 50 cases.

Background/Objectives:  Tinea nigra is a relatively uncommon dematiaceous fungal infection of the palms and soles, which clinically may mimic a melanocytic lesion. We sought to ascertain how frequently misdiagnosis of this infection occurred and whether the use of dermoscopy helped in its diagnosis.

Dermatoscopy of flat pigmented facial lesions

The diagnosis of flat pigmented lesions on the face is challenging because of the morphologic overlap of biologically different lesions and the unknown significance of dermatoscopic patterns.

Dermoscopy and entomology (entomodermoscopy)

Although dermoscopy has been primarily designed for aiding the in vivo diagnosis of skin tumors, recent advances indicate it is also useful in the diagnosis of common skin infections and infestations. As such, dermoscopy connects the research fields of dermatology and entomology into one field of “entomodermoscopy”. In this article we give an overview on the current applications of entomodermoscopy.

Dermoscopy of scalp tumours: a multi-centre study conducted by the international dermoscopy society

Background  Little is known about the dermoscopic features of scalp tumours.

Clinical and dermoscopic characteristics of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with a high mortality rate. Diagnosis is often delayed.

Can noninvasive imaging tools potentially predict the risk of ulceration in invasive melanomas showing blue and black colors

The aim of this study was to evaluate the reflectance microscopy and histopathologic correlates of dermoscopic blue and black color (BB) in a series of melanomas. We searched our database for dermoscopic images of histopathologically diagnosed pigmented nodular melanomas (pNM), superficial spreading melanomas with a nodular component (SSM+Nod), and melanoma metastasis (METs). All cases were assessed for the presence of dermoscopic BB. Confocal microscopy findings were then compared with those of histopathology. A total of 17 BB-positive tumors including eight pNMs, five SSM+Nod, and four METs were included in the study. We identified two different dermoscopic patterns associated with black color, namely, large black blotches and irregular black dots/globules, which corresponded to two different confocal and histopathologic findings. Black blotches resulted from a total filling of the epidermis by an upward migration of melanocyte nests and pagetoid melanocytes as single cells and clusters, whereas black dots/globules also corresponded to the upward migration of melanocyte nests in the epidermis and pagetoid spread, but with sparing of intervening areas of epidermis. Interestingly, two pNM and two METs showing black color lacked any epidermal involvement and, instead, they were characterized by upward-bulging dermal masses of atypical melanocytes covered by an highly attenuated epidermis. In both cases, black color corresponded to pigment-containing melanocytes in close proximity to the surface of the skin. Our study suggests that black color results not only from epidermal melanin but also from a dense dermal proliferation of pigmented melanocytes under a thinned epidermis. It seems reasonable to suggest that a bulging proliferation of dermal melanocytes beneath a thin epidermal layer could precede ulceration. As ulceration is a very significant prognostic factor, speculation arising from this study that dermoscopic black color may in some cases indicate incipient ulceration is worthy of further study.

Prediction without Pigment: a decision algorithm for non-pigmented skin malignancy

While there are several published comprehensive stepwise algorithmic methods for diagnosing pigmented skin malignancy, only limited material has been published for the stepwise assessment of non-pigmented lesions. We present a method based on pattern analysis, with a stepwise assessment, first, for ulceration, second, for white clues (defined as white lines, or in the case of a raised lesion any of the keratin clues: dermatoscopic white circles, dermatoscopic white structureless areas or surface keratin), and third, if no ulceration or white clues are present, proceed to vessel pattern analysis. This is a novel method, and apart from the assessment of white clues in raised lesions, it has not been formally tested. The priority of keratin clues in raised lesions over vessel pattern analysis has, however, been verified. It is conceded that this method is less specific than methods which have clues of pigmented structures, and accepting these limitations, Prediction without Pigment is a decision algorithm intended to guide the clinician in the decision as to whether to perform a biopsy rather than consistently leading to a specific diagnosis. Reaching a more specific diagnosis at the end of our flowchart can be achieved by weighing of clues both clinical and dermatoscopic, and that ability can be expected to improve with both knowledge and experience, but no diagnostic method, including this one, can be 100% sensitive in diagnosing malignancy, in particular, melanoma. Taking these limitations into account, any non-pigmented lesion, regardless of pattern analysis, which is raised and firm (nodular) and for which a confident, specific benign diagnosis cannot be made, should be excised to exclude the nodular variant of amelanotic melanoma.