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. OBJECTIVE: The purpose of this study was to investigate a series of vascular lesions by means of OCT in order to obtain new insights into the non-invasive, pre-operative analysis of these lesions. METHODS: Seven vascular lesions were included in the study. Histopathological diagnosis showed two haemangiomas and one haemolymphangioma; the remaining four cases were classified as haemangiomas on the basis of their clinical appearance. RESULTS: In all lesions, OCT analysis was able to visualize different areas of the lesion from the horny layer to the dermis showing a clear image of the vascular proliferation. Specifically, oval to roundish signal-poor areas sharply demarcated by a surrounding signal-rich layer were observed in good correlation with histopathology. CONCLUSION: The analysis of vascular lesions by OCT provides a new insight into non-invasive diagnosis and can be helpful in the selection of the most appropriate treatment.

Itch, pain, and metaesthetic sensation.

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.

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

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.

Addition of dermoscopy to conventional naked-eye examination in melanoma screening: a randomized study.

OBJECTIVE: We sought to assess the difference in lesion management between combined examination (naked-eye and dermoscopy) and conventional naked-eye examination in evaluations for melanoma; and to assess the impact on patient treatment of facilities for digital follow-up of diagnostically equivocal lesions. METHODS: We conducted a randomized, controlled trial at a pigmented lesion clinic in a university hospital. A total of 938 consecutive subjects presenting between November 1, 2001, and March 31, 2002, were eligible and 25 were excluded because they were younger than 12 years of age; hence 913 subjects were enrolled. Participants were randomized to combined examination with mandatory excision of equivocal lesion (arm B) and with possibility of digital follow-up according to the clinician's decision (arm C), or to conventional naked-eye examination (mandatory excision of equivocal lesion) (arm A). The same pigmented lesion clinic staff examined all subjects. RESULTS: Combined examination determined a significant reduction in the percentage of patients referred for operation (9.0% vs 15.6%) (P =.013). When facilities for digital follow-up of equivocal lesions were available, the percentage of patients classified as harboring lesions difficult to diagnose increased (group C, 35.8%; group B, 17.8%; P <.01). About half of them were immediately referred for operation whereas the remainder submitted to second examination (digital follow-up). Two melanomas (1 in situ and 1 invasive, 0.40-mm thick) were diagnosed after second examination performed 6 months later. The number of melanomas eventually excised within the study were similar among the 3 allocation groups (3, 2, and 3, respectively). CONCLUSIONS: the addition of dermoscopy to conventional naked-eye examination is associated with a significant reduction of number of pigmented skin lesions excised for diagnostic verification. The possibility of digital follow-up of equivocal lesions is associated with a not negligible occurrence of initial melanomas left unexcised until the second consultation.

Pigmented Bowen's disease mimicking cutaneous melanoma: clinical and dermoscopic aspects.

BACKGROUND: Pigmented Bowen's disease (BD) (squamous cell carcinoma in situ) has been rarely described among white patients. OBJECTIVE AND METHODS: We report the case of a 48-year-old white male presenting a lesion of pigmented BD on his left thigh, clinically mimicking a superficial spreading melanoma. RESULTS: Naked-eye physical examination revealed a single 1.8 x 1.5 cm, hyperpigmented plaque with a rough surface, which appeared irregularly shaped and sharply demarcated. The assessment of this uncommon tumor by means of dermoscopy, never reported in literature before, was performed. According to standardized terminology, none among the well-established dermoscopic criteria useful to discriminate between melanocytic and nonmelanocytic origin was detected within the lesion. A reticular pigmentation simulated remnants of atypical pigment network, being of uncertain diagnostic value in the preoperative classification of the lesion. Other recognized patterns were irregular, brown globular structures and wide regression-like areas. None of the features diagnostic for pigmented basal cell carcinoma was found as well. CONCLUSION: The correct classification of nonmelanocytic origin of the lesion was therefore achieved only at histologic examination, after the complete surgical excision. In spite of its rarity, pigmented BD should be included among those lesions, which may simulate cutaneous melanoma. According to criteria validated by literature, dermoscopy failed to improve a preoperative classification of this peculiar skin tumor.

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.

Multiple synchronous cutaneous melanomas: implications for prevention.

BACKGROUND: A subset of about 3-5% of melanoma patients present a second primary melanoma. OBSERVATIONS: We describe two cases of primary multiple synchronous melanomas consecutively observed in the last 6 months in our department in two male patients presenting multiple atypical nevi. In both patients, the second melanoma was diagnosed by the clinician who had identified the first one, but at the time of the first follow-up consultation, 3 months later. The delayed discovery of the second melanoma required another referral for surgery with additional discomfort for the patients. Concern about the first lesion (the thickest in both cases) probably rendered the second one less evident to both patients and clinician, until the first follow-up examination after excision of the first lesion. CONCLUSION: We stress the need for careful and thorough examination of the whole body surface at the time of detection of a cutaneous melanoma in subjects with multiple atypical moles because the finding of synchronous multiple melanomas is not uncommon.

False "melanocytic" parameters shown by pigmented seborrheic keratoses: a finding which is not uncommon in dermoscopy.

BACKGROUND: Dermoscopic evaluation of pigmented lesions includes assessment of criteria suggestive of melanocytic proliferation. Dermoscopic diagnosis may be hampered when a nonmelanocytic lesion displays one or more melanocytic features. OBJECTIVE: To evaluate the incidence of misleading dermoscopic features characteristic of melanocytic lesions in pigmented seborrheic keratosis (PSK). METHODS: We evaluated 402 clinically typical PSKs from 138 patients with at least one clinically identifiable PSK. RESULTS: Approximately 10% of PSKs displayed one or more melanocytic features, the most frequent being a "false" pigment network. CONCLUSION: The occurrence of a "false" pigment network in PSK can be misleading in the differential diagnosis of clinically equivocal lesions. A correct diagnosis can only be obtained if all available dermoscopic criteria are appropriately assessed together with the clinical examination.

Multiple synchronous pigmented basal cell carcinomas following radiotherapy for Hodgkin's disease.

BACKGROUND: Multiple basal cell carcinomas (BCCs) are infrequently seen in patients under 30 years of age. Their occurrence at a young age is often linked to some genodermatosis, including Nevoid Basal Cell Carcinoma Syndrome (NBCCS). The exposure to ionizing radiation is also considered to be a predisposing factor in the development of BCCs. METHODS: We report the case of a 35-year-old patient who presented with seven synchronous, nodular, brownish-pigmented BCCs, confined within the radiation-treated cutaneous areas, 15 years after receiving Cobalt-60 (60Co) irradiation for Hodgkin's disease. RESULTS: On the basis of clinical, radiological, and anamnestic data we excluded a NBCCS, thus proposing irradiation as the cause of the multiple synchronous pigmented BCCs. CONCLUSIONS: Previous therapeutic ionizing radiation leads to an increased risk of BCCs confined to the region of the body to which radiotherapy was delivered. We consider our patient's BCCs represents a late adverse effect of the treatment with Cobalt-60.