Alex Chamberlain

Dermatoscopy aids in the diagnosis of the solitary red scaly patch or plaque–features distinguishing superficial basal cell carcinoma, intraepidermal carcinoma, and psoriasis

BACKGROUND Intraepidermal carcinoma (IEC), superficial basal cell carcinoma (sBCC), and psoriasis are common entities that may all present as well-defined, brightly erythematous plaques. Currently, there are limited data on the dermatoscopic features that differentiate these diagnoses. OBJECTIVE We sought to describe the most significant morphologic findings seen on dermatoscopy of IEC, sBCC, and psoriasis, and formulate a diagnostic model based on these features. METHOD We conducted a retrospective observational study using macrophotography and dermatoscopy to evaluate the presence or absence of dermatoscopic features and formulated diagnostic models for each diagnosis. A convenient sample of 300 lesions was collected from 255 patients from two hospital dermatology clinics and 4 private dermatology practices. These comprised 150 cases of sBCC, 100 cases of psoriasis, and 50 cases of IEC. RESULTS The most significant dermatoscopic features of IEC were a clustered vascular pattern, glomerular vessels, and hyperkeratosis. When all 3 features were observed together, the diagnostic probability for IEC was 98%. sBCCs were characterized by a scattered vascular pattern, arborizing microvessels, telangiectatic or atypical vessels, milky-pink background, and brown dots/globules; the diagnostic probability was 99% if 4 of these 6 features were identified. For psoriasis, the significant features identified were a homogenous vascular pattern, red dots, and light-red background, yielding a diagnostic probability of 99% if all 3 features were present. LIMITATIONS Lack of evaluation of interobserver/intraobserver reproducibility is a limitation. CONCLUSION Dermatoscopy is valuable in the diagnosis and differentiation of IEC, sBCC, and psoriasis because of consistent dermatoscopic morphology.

Efficacy of imiquimod cream, 5%, for lentigo maligna after complete excision: a study of 43 patients.

OBJECTIVE To determine the efficacy of imiquimod cream, 5%, in the treatment of lentigo maligna (LM). DESIGN Open-label before-and-after interventional study. SETTING A multidisciplinary melanoma clinic at a major tertiary hospital. PATIENTS Forty-three patients with biopsy-proven LM of greater than 5 mm in diameter completed this study. INTERVENTIONS Imiquimod cream, 5%, was applied to the lesion 5 days a week for 12 weeks. The original lesion was excised with a 5-mm margin. MAIN OUTCOME MEASURES The primary outcome was histopathologic evidence of LM in the excision specimen assessed independently by 2 of 3 dermatopathologists. Visible inflammation during treatment and macroscopic clearance were recorded. RESULTS When 5 of the 43 patients with discordant histopathologic assessment of the excision specimen were excluded, 20 of 38 patients (53% [95% confidence interval, 36%-69%]) demonstrated histopathologic clearance of LM after imiquimod treatment. Visible inflammation was significantly associated with histopathologic clearance (P = .04), but the positive predictive value was low (62%). Macroscopic clearance showed some association with histopathologic clearance (P = .11). Dermatopathologist concordance for all 43 specimens was substantial (κ = 0.77; 95% confidence interval, 0.57-0.96). CONCLUSIONS Imiquimod cream, 5%, has limited efficacy in the treatment of LM when determined by histopathologic assessment of the entire treated area. The clinical signs of visible inflammation during treatment and apparent lesion clearance cannot be relied on to assess efficacy.

Susan J Robertson,' Jane Leonard' and Alex J Chamberlain

A 16‐year‐old boy presented with a number of asymptomatic pigmented macules on the volar aspect of his index fingers. Dermoscopy of each macule revealed a parallel ridge pattern of homogenous reddish‐brown pigment. We propose that these lesions were induced by repetitive trauma from a Sony PlayStation® 3 (Sony Corporation, Tokyo, Japan) vibration feedback controller. The lesions completely resolved following abstinence from gaming over a number of weeks. Although the parallel ridge pattern is typically the hallmark for early acral lentiginous melanoma, it may be observed in a limited number of benign entities, including subcorneal haematoma.

Dermoscopic features of clear cell acanthoma: five new cases and a review of existing published cases

Clear-cell acanthoma (CCA), or Degos acanthoma, is a rare clinical entity first described by Degos and colleagues in 1962. Traditionally thought to be a form of benign epidermal neoplasia, CCA has also been suggested to be a form of non-specific reactive dermatosis or localised psoriasis, in view of changes in the dermal microvasculature and immunohistochemical findings. On histopathology CCA is characterised by a well-demarcated area of psoriasiform epidermal hyperplasia with keratinocytes with palestaining cytoplasm. Mild spongiosis, exocytosis of neutrophils and thinning of the suprapapillary plates may also be evident. CCA typically arises on the lower extremities, with a peak age of incidence of 60 years and both sexes are equally affected. In most cases CCA presents as a solitary, slowgrowing pink, red or brown papule or nodule that is moist, well-circumscribed and typically 3 mm–2 cm in diameter. The surface may resemble a vascular lesion such as pyogenic granuloma. Occasionally patients present with multiple lesions. CCA is commonly mistaken for basal cell carcinoma, irritated seborrhoeic keratosis, squamous cell carcinoma, amelanotic melanoma or even psoriasis. Dermoscopic recognition of CCA may help to avoid unnecessary biopsies or surgical excision. There are few reports on the dermoscopic features of CCA and we endeavour here to review comprehensively the features of all dermoscopic images of CCA presented in the literature. We review these images and report five new cases of our own (a total of 20 cases) in order to delineate the key dermoscopic features of CCA. CASE REPORTS

Clinical practice guidelines for the diagnosis and management of melanoma: melanomas that lack classical clinical features.

Introduction: A Cancer Council Australia multidisciplinary working group is currently revising and updating the 2008 evidence‐based clinical practice guidelines for the management of cutaneous melanoma. While there have been many recent improvements in treatment options for metastatic melanoma, early diagnosis remains critical to reducing mortality from the disease. Improved awareness of the atypical presentations of this common malignancy is required to achieve this. A chapter of the new guidelines was therefore developed to aid recognition of atypical melanomas.

Subungual fibro-osseous pseudotumour of the toe

Subungual fibro‐osseous pseudotumour of the toe is a rare osseous soft tissue tumour of which only six cases have been described in the literature. We present a case in a teenage boy that posed an instructive diagnostic challenge and discuss the distinguishing features of the various differential diagnoses. The subungual location is very rare. For such tumours, radiology is as vital as histopathology in making a diagnosis and excluding neoplasia. Accurate diagnosis requires careful clinico‐pathological and radiological correlation. These sorts of lesions may present to the dermatologist, not always the foot surgeon.

Oxford Handbook of Medical Dermatology

Giving concise and clear guidance on investigation and treatment, this handbook helps doctors adopt a step-by-step approach at the bedside to make sense of skin problems by analyzing clinical signs. Illustrated and in full color, it covers skin physiology, an overview of common skin conditions, and skin problems commonly seen in a broad range of specialities, from rheumatology to psychiatry, as well as children and the elderly.

Photographic artefact simulating regressing melanocytic lesion: a potential pitfall of total body photography.

Clinical photography has become a vital adjunctive tool for all dermatologists and is well supported as a means for monitoring patients with multiple or atypical naevi and a history of melanoma. The preferred type of camera for this purpose is a digital single-lens reflex (DSLR) camera. Most professional photographers choose the DSLR because they allow an accurate preview of framing close to the moment of exposure. Furthermore, DSLR cameras allow the option of interchangeable lenses and larger sensors compared to most compact digital cameras. The drawback of frequent lens changes is that this allows dust to enter the internal workings of the camera. Specks of dust on the DSLR camera sensors appear as tiny black dots in the image (visual artefacts) and these affect image quality and integrity. These visual artefacts become a significant issue when monitoring patients using total body photography (TBP). Our recent experience illustrates this situation. A 34-year-old woman with a history of lentigo maligna and atypical naevi had baseline TBP to aid annual skin surveillance. At her first follow-up visit post-melanoma diagnosis, a deeply pigmented lesion was noticed on the right upper thigh in her photographs (Fig. 1) without a corresponding lesion in situ. After consideration, it was felt that the lesion had possibly regressed. On reflection, and after examining other sites using her TBP for comparison, it was felt that the pair of pigmented lesions was present at the same site on each photograph and this was most likely a photographic artefact. We raised our problem with the hospital medical photographers and they related that other colleagues had also expressed a similar experience. The primary issue is contamination by dust when changing DSLR lenses. Dust that adheres to the image sensor affects image quality by appearing as black specks or dots and can only be removed by careful cleaning. We have encountered the same issue with dermoscopic imaging in which dust and artificial fibres contaminate hardware. Burroni and colleagues report pseudocystic lesions on dermoscopic imaging that are due to dust suspended in contact media, causing an optical disturbance in the same way. Various cleaning techniques exist, such as using compressed air to clean the mirror box and shutter area or a swab soaked in an isopropyl-based solution to clean the filter surface. Dust reduction systems are now becoming more common in DSLR. While a compact digital camera with a fixed lens does not expose the sensor to dust, the non-zoom versions utilise wider angle lenses than are practical for patient photography. The qualities of zoom lenses, while much better nowadays, are still inferior to prime (single focal length) lenses. For a medical photography department or commercial providers of body mapping photography, one solution would be to dedicate one camera to the appropriate lens used for TBP (e.g.100 mm) and never change it, and using a separate camera body for other lenses. Our experience highlights the potential pitfall of photographic artefacts affecting the utility of TBP. Regular cleaning of photographic hardware, ideally by professionals, is probably the solution to the problem.