Marcello Stante

Pattern analysis, not simplified algorithms, is the most reliable method for teaching dermoscopy for melanoma diagnosis to residents in dermatology

Summary Background Simplified algorithms for dermoscopy in melanoma diagnosis were developed in order to facilitate the use of this technique by non‐experts. However, little is known about their reliability compared with classic pattern analysis when taught to untrained observers.

Dermoscopy for early detection of facial lentigo maligna

Up until now, only lesions selected on the basis of their clinical atypia or which appear equivocal on naked eye examination have been shown to benefit from the use of dermoscopy. In our experience, dermoscopic evaluation of lesions located on the face may require a different approach, as a histopathological diagnosis of malignancy is not uncommon in clinically trivial lesions (i.e. lesions lacking the ABCD criteria for clinical suspicion). Moreover, at this site dermoscopy reveals specific criteria according to the particular histological architecture shown by sun‐damaged skin. We report four cases of lentigo maligna (LM) of the face whose identification depended on dermoscopic examination which was performed routinely on all facial lesions, as the lesions did not show ABCD clinical criteria for malignancy. In our experience, the identification of early signs of malignancy by dermoscopy may indicate the excision of LM at an early phase, before the lesion is associated with the ABCD signs of melanoma. Dermatologists should avoid the mistake of immediately excluding a diagnosis of malignancy when examining an ABCD‐negative pigmented skin lesion of the face.

Dermatoscopy in the diagnosis of pigmented skin lesions: a new semiology for the dermatologist.

Dermatoscopy or epiluminescence microscopy (ELM), is a noninvasive method that enables clinicians to evaluate fully – by means of a magnified oil immersion diascopy – numerous morphological features, not visible with the naked eye, which enhance the diagnosis of nearly all pigmented skin lesions. In recent years, a burst of research activity in this topic has been carried out, dealing with different aspects, and new frontiers, of this technique. First, a continuous refinement of dermatoscopic terminology is undertaken, paying particular attention to the diagnostic performance of dermatoscopy at peculiar anatomical sites and to the building of different dermatoscopic algorithms aimed at a simplified diagnosis of melanoma, even for less experienced observers. Another point of interest concerns the possible role of dermatoscopy in the pre‐operative assessment of melanoma thickness. Finally, promising data about the role of digital equipment in the follow up of melanocytic skin lesions as well as in the automated diagnosis of pigmented skin lesions have been recently reported. This paper should enable readers to become familiar with the procedure and terminology of ELM in the diagnosis of pigmented skin lesions encouraging a greater understanding of different methods (pattern analysis, algorithms) in the diagnosis of melanoma using ELM.

Possible histopathologic correlates of dermoscopic features in pigmented melanocytic lesions identified by means of optical coherence tomography.

Abstract:  Optical coherence tomography (OCT) is a novel non‐invasive imaging technique for in vivo histologic characterization of tissues. Besides pure morphology, additional functional parameters of the tissue investigated can be evaluated at the same time, such as the refractive index and the scattering coefficient. The purpose of our study is to correlate in vivo the dermoscopic structures that first appear in the melanocytic pigmented lesion (pigment network and brown globules) using this new method, with the histopathologic correlates, in order to improve their characterization and achieve easier recognition and inter‐observer reproducibility. We concentrated in particular on the pigment network and the brown globules, as these are dermoscopic parameters of great diagnostic importance in melanocytic lesions. Moreover, as these parameters are the histopathologic equivalents of structures located at the level of the dermo‐epidermal junction, they enable a correct evaluation to be made using OCT, that at present has only a few millimetres penetration power. The results of our trial, performed using the histopathological preparation as an evaluation gold standard, show that in selected cases OCT allows an in vivo correlation to be made between surface dermoscopic parameters and histopathologic correlates, in particular the pigment network and brown globules. The resolution is not high enough to reveal the morphology of the single cells, but it is possible to evaluate the architecture of a lesion.

Cutaneous endometriosis: non-invasive analysis by epiluminescence microscopy

Summary The clinical appearance of cutaneous endometriosis can share some features with malignant melanoma, thus representing a possible cause for concern in both patient and clinician. In recent years, the use of epiluminescence microscopy (ELM, dermoscopy) has proved useful in improving the accuracy of diagnosis of pigmented skin lesions. The purpose of this study was to analyse the dermoscopic features of cutaneous endometriosis with histopathological correlation. We studied a case which showed homogeneous reddish pigmentation, regularly distributed. Within this typical pigmentation there were small red globular structures, but more defined and of a deeper hue, which we called ‘red atolls’. ELM thus revealed a distinctive pattern in cutaneous endometriosis.

Non-invasive analysis of melanoma thickness by means of dermoscopy: a retrospective study.

Epiluminescence microscopy (ELM), or dermatoscopy, is a non-invasive technique for the diagnosis of cutaneous melanoma that may play a role in the non-invasive, preoperative assessment of melanoma thickness. This study investigated the correlation between the frequency of appearance of some standard ELM criteria and the histological thickness of melanomas. In addition, the possible role of the total dermoscopic score (TDS) according to ABCD rule of dermoscopy as a predictor of melanoma thickness was analysed. The dermoscopic images of 84 cutaneous melanomas were retrospectively investigated to evaluate the presence of 10 standard ELM criteria, and for each lesion the TDS was established (with observers blinded as to the tumour thickness). A statistically significant association was found between the presence of an irregular pigment network and melanomas with a Breslow index equal to or lower than 0.75 mm (positive predictive value of 68%); in contrast, radial streaming, atypical vascular pattern and grey-blue areas were associated with melanomas > 0.75 mm (positive predictive values of 77%, 65% and 70%, respectively). Of the melanomas thinner than 0.76 mm, 82% showed a TDS lower than 6.80 (optimized cut-off point), while 79% of melanomas thicker than 0.75 mm had a TDS higher than 6.80 (χ2 = 30.815, P < 0.001); the positive predictive value of a TDS > 6.80 in the detection of lesions thicker than 0.75 mm was 79%. In conclusion, a statistically significant correlation does exist between some dermoscopic features and melanoma thickness. Both the mostly used dermoscopic methods (standard ELM pattern analysis and the ABCD rule of dermatoscopy) may provide useful information in the non-invasive assessment of melanoma thickness. However, their diagnostic performance is far from 100%; further studies are needed to investigate whether the combination of dermoscopy with other non-invasive approaches (e.g. sonometry) may result in an overall improvement in the diagnostic performance.

Application of optical coherence tomography in non‐invasive characterization of skin vascular lesions

Background: Optical coherence tomography (OCT) is a new non‐invasive approach for real‐time in vivo tissue characterization. A promising use of OCT can be the assessment of the architecture of lesions with some degree of inhomogeneities, such as vascular lesions. Knowledge of the size and depth of the vascular structures can be useful for the diagnosis and for choosing the best treatment.

Allergic contact dermatitis from henna temporary tattoo

484 JEADV 2006, 20, 461–488

Itch, pain, and metaesthetic sensation.

ABSTRACT:  Itch is one of the alarm sensations that human beings have phylogenetically evolved for a defense purpose. Many theories and evidences regarding the biological, pathophysiological, and clinical aspects have been given, but an update on the neuroanatomy paths and consequent treatments is required. Some chemicals that are released after skin injury and facilitate the inflammatory process can induce itch or pain or basically lead to a sensitization of the nociceptor response. In clinical practice, the present authors note a continuum of sensations from touch to pain, among which many metaesthetic sensations can be described, even if the patients themselves cannot precisely define them. The specificity of itch neurons is therefore based on their spinal connections to the itch pathway rather than on unique peripheral receptors. The ambiguity of “itch unit” discharge to pruritics and algogens may be solved by the central inhibition of itch by pain: it is common knowledge that scratching relieves itching. Conversely, centrally acting pain‐inhibiting opioids enhance itch by disinhibition. The relation between itch and pain is interesting in its clinical and physiopathological aspects in order to select appropriate treatment.

Effect of Lesion Size on the Diagnostic Performance of Dermoscopy in Melanoma Detection

Background: Dermoscopy is able to correctly classify a higher number of melanomas than naked-eye examination. Little is known however about factors which may influence the diagnostic performance during practice. The aim of the study was to analyze the effect of size of the lesion on diagnostic performance of dermoscopy in melanoma detection. Methods: Eight dermatologists examined clinical and, separately, clinical and dermoscopic (combined examination) images of 200 melanocytic lesions previously excised [64 melanomas, 24 in situ and 40 invasive (median thickness 0.30 mm) and 136 melanocytic nevi]. After examination, diagnostic performance was analyzed in accordance with the major diameter of the lesions divided into 3 groups, i.e. small (less than 6 mm), intermediate (between 6 and 9 mm) and large (10 mm or more) lesions. These groups were shown to be highly comparable concerning the microstaging of melanomas (median thickness value 0.30, 0.22 and 0.32 mm, respectively). Results: Dermoscopy increased the diagnostic performance of naked-eye examination of both intermediate and large lesions [sensitivity value: +19.3 (p = 0.002) and +10.3 (p = 0.007); diagnostic accuracy value: +7.4 (p = 0.004) and +6.1 (p = 0.07)]. On the contrary, no statistically significant increase was found dealing with small lesions (sensitivity +3.7, p = 0.66; diagnostic accuracy –1.7, p = 0.55). Conclusions: The diagnostic improvement associated with the addition of dermoscopy to naked-eye examination is influenced by the size of the lesion, i.e. it is lacking with lesions up to 6 mm in diameter. The optimized use of dermoscopy in melanoma detection is obtained dealing with melanocytic lesions 6 mm in diameter or larger.