In vivo reflectance confocal microscopy of erythematosquamous skin diseases

Background:  In vivo reflectance confocal microscopy (RCM) represents a promising imaging tool that allows a non-invasive examination of skin morphology in real time at nearly histological resolution, showing microanatomical structures and individual cells.
Objectives:  The aim of our study was to evaluate the diagnostic accuracy of confocal examination of erythematosquamous skin diseases, to define typical RCM-features and assess them for their presence or absence, diagnostic performance and reliability.
Methods:  Three independent observers received standardized instructions about diagnostic RCM-features of erythematosquamous skin diseases. A total of 1700 RCM images obtained from 75 patients with psoriasis, contact dermatitis, mycosis fungoides, chronic discoid lupus erythematosus (CDLE) or subacute cutaneous lupus erythematosus (SCLE) and from 10 'healthy adults' without any skin disease were evaluated by each observer.
Results:  Overall, sensitivity and specificity values as observed by three observers were, respectively, 89.13% and 95.41% for psoriasis; 83.33% and 92.31% for contact dermatitis; 62.96% and 94.53% for SCLE/CDLE; and 63.33% and 92.89% for mycosis fungoides.
Conclusions:  Reflectance confocal microscopy examination appears to be a promising method for non-invasive assessment of erythematosquamous skin diseases. This study provides a set of well-described morphological criteria with obvious diagnostic impact, which should be used in further investigations.     

Reflectance confocal microscopy as a new diagnostic tool in transformed mycosis fungoides

Patients with mycosis fungoides typically experience an indolent disease. In some cases, the disease undergoes a process of large cell transformation which often heralds a more aggressive course with shortened overall survival. In order to rule out large cell transformation, biopsy specimens are often collected from patients with established disease who develop new papules, plaques or tumours. In some cases, multiple biopsies are needed and scar, infection and sampling error can occur. Our aim was to evaluate lesions suggestive of large cell transformation using in vivo reflectance confocal microscopy and to correlate confocal features with histopathologic findings in three patients with biopsy-proven mycosis fungoides who developed new lesions during follow-up. A total of six lesions, two lesions per patient, were examined. Reflectance confocal microscopy demonstrated large bright roundish pleomorphic cells in the epidermis, dermoepidermal junction, dermis and hair follicle in 5 of 6 lesions. The same 5 lesions were confirmed as large cell transformation by histopathology. Dermoepidermal junction obscuration, Pautrier microabscesses, epidermal disarray, spongiosis and dendritic cells were also detected by reflectance confocal microscopy and correlated to histopathology. In conclusion, reflectance confocal microscopy is useful in identifying large cell transformation within mycosis fungoides lesions. Reflectance confocal microscopy can therefore be of value in targeting the biopsy site, thereby reducing the chance of a false-negative histopathological finding.     

In vivo reflectance confocal microscopy detects pigmentary changes in melasma at a cellular level resolution

Please cite this paper as: In vivo reflectance confocal microscopy detects pigmentary changes in melasma at a cellular level resolution. Experimental Dermatology 2010; 19 : e228–e233. Abstract: Melasma is a frequent pigmentary disorder caused by abnormal melanin deposits in the skin. In vivo reflectance confocal microscopy (RCM) is a repetitive imaging tool that provides real‐time images of the skin at nearly histological resolution. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders are the most suitable candidates for RCM examination but RCM features of melasma have never been reported. This study investigates the pilot use of RCM in melasma to provide a set of well‐described morphological criteria with histological correlations. RCM images were acquired from melasma skin and compared to adjacent control skin in 26 patients. Skin biopsies were obtained from eight patients. In the epidermis, RCM showed in all patients a significant increase in hyperrefractile cobblestoning cells. These cells corresponded to hyperpigmented basal keratinocytes in histology. In six patients, dendritic cells corresponding to activated melanocytes were also found in the epidermis. In the dermis, RCM identified in nine patients plump bright cells corresponding to melanophages. Interestingly, for a given patient, the topographic distribution of melanophages in melasma lesions was very heterogeneous. RCM also showed a significant increase in solar elastosis and blood vessels in the dermis. RCM is a non‐invasive technique that detects pigmentary changes in melasma at a cellular level resolution. Therefore, RCM provides an innovative way to classify melasma by pigment changes.     

An investigation of striae distensae using reflectance confocal microscopy

Background: Striae distensae, otherwise known as stretch marks, are white or red scar‐like streaks on the skin. Although they are not associated with adverse health outcomes, striae are associated with significant cosmetic morbidity. While they have been well characterised histopathologically, a non‐invasive method of microscopic lesion assessment of striae would be welcome. Methods: To gain insight into the small‐scale morphological features associated with striae we undertook an in vivo investigation of nine patients with striae alba and one with striae rubra utilising reflectance confocal microscopy (RCM). Results: Here we demonstrate that features known to be present using light microscopy, such as parallel collagen bundles in the dermis, and some features that are not well recognised by light microscopy, including distortion of dermal papillae, are demonstrable using RCM. Conclusions: Characterising the features of early and established striae distensae with confocal microscopy is an important foundation for future work. The potential ability to reliably identify the earliest pathological changes in skin in early lesions or before clinically manifest striae develop – a task facilitated by our findings – will increase the understanding of their pathogenesis and will have significant practical utility in monitoring the impact of future preventative interventions.     

Phototherapy for cutaneous T-cell lymphoma

Phototherapy has been utilized for decades in the treatment of various dermatologic conditions, including cutaneous T-cell lymphoma (CTCL). Currently, a number of light sources are available, and selection of the specific modality is based on a number of factors, the most important of which is disease stage. The efficacy of broadband ultraviolet B (UVB) is limited to the patch stage, while psoralen and ultraviolet A (PUVA) is capable of clearing plaques and, sometimes, early tumors. Narrowband UVB is also effective for early stages and has practical advantages over PUVA, but more studies are needed to more fully evaluate its role in CTCL. Long-wave ultraviolet A (UVA1) has likewise shown efficacy, supported by findings of apoptosis induction in UVA1-treated cells. Long-term remissions have been reported for PUVA, but in the majority of cases, maintenance therapy was necessary. Although beneficial as monotherapy for early stages of the disease, phototherapy is also a useful adjunct to other modalities such as interferons, retinoids and electron beam therapy. Studies are ongoing to refine protocols for combination therapy, with the goal of improving efficacy, while minimizing adverse effects.     

In vivo reflectance confocal microscopy assessment of the therapeutic follow‐up of cutaneous T‐cell lymphomas causing scalp alopecia

Cutaneous T‐cell lymphomas involving the scalp and determining scarring alopecias are difficult to be followed up during treatment because of the peculiar anatomical site of onset. In vivo reflectance confocal microscopy has already been reported to be useful for cutaneous T‐cell lymphoma evaluation and for therapeutic follow‐up in inflammatory skin conditions. We describe a case of a 26‐year‐old man affected by cutaneous T‐cell lymphoma affecting the scalp in which reflectance confocal microscopy demonstrated to be useful for in vivo evaluation of the therapeutic response to topical and systemic treatment.     

Treatment planning in cutaneous T-cell lymphoma

Effective long-term management of cutaneous T-cell lymphoma (CTCL) requires administration of skin-directed therapies such as topically applied nitrogen mustard or photochemotherapy to achieve a complete response in clinically early disease (patch and thin-plaque-phase mycosis fungoides, MF) and often the concomitant administration of well-tolerated drugs with systemic effects such as interferon alfa, bexarotene, methotrexate or extracorporeal photopheresis in more advanced, but not highly aggressive/nontransformed disease (thick plaque or tumor phase MF or erythrodermic CTCL). The author's approach is provided as a guide for dermatologists in private practice.     

Preliminary evaluation of vitiligo using in vivo reflectance confocal microscopy

BACKGROUND: Vitiligo is the most common pigmentary disorder with a global incidence from 0.1% to 2% in different geographical areas. Histopathology and histochemistry have shown the reduction of melanocytes in achromic patches, but microscopic changes of lesional and non-lesional skin are still not completely understood. Reflectance confocal microscopy (RCM), based on the different light reflectance index of cutaneous structures, allowed in vivo, en face microscopic evaluation of superficial skin layers with a resolution similar to skin histology. AIM: The purpose of this study was to evaluate RCM features of lesional and non-lesional skin of vitiligo patients. Moreover, re-pigmented areas were taken into consideration in order to evaluate melanocyte response to ultraviolet B (UVB) radiation. SUBJECTS AND METHODS: Sixteen patients of different phototypes affected by active non-segmental vitiligo and 10 controls were enrolled in the study. In vivo skin imaging was done using a commercially available RCM (Lucid, Vivascope 1500. Re-pigmented areas from 6 to 16 patients (after UVB narrow-band therapy) were also examined. RESULTS: Vitiligo lesions showed the disappearance of the bright rings normally seen at the dermo-epidermal junction. Moreover, non-lesional skin of vitiligo patients showed unexpected changes as the presence of half-rings or scalloped border-like features of the bright papillary rings. In re-pigmented areas after UVB narrow band therapy, the presence of activated, dendritic melanocytes was seen. CONCLUSIONS: Considering our results, and following further studies, RCM clinical applications could be used in the therapeutic monitoring and evaluation of the evolution of vitiligo.     

Establishing the dynamics of neutrophil accumulation in vivo by reflectance confocal microscopy

Reflectance confocal microscopy (RCM) is an imaging tool, which visualizes the epidermal skin layers in vivo with a cellular resolution. Neutrophil accumulation is a characteristic feature in psoriasis and is thought to play a role in the pathophysiology of psoriasis. Until now, imaging of neutrophil accumulation in vivo is not performed. We evaluated the dynamics of neutrophil migration in active psoriatic lesions by non‐invasive RCM imaging. Additionally, we evaluated the time phasing and duration of neutrophil trafficking. We performed RCM imaging prior to the start of topical treatment and for seven consecutive days with a 24‐h time interval at the Radboud University Medical Center, Nijmegen, the Netherlands. Twelve psoriatic lesions in three patients with a severe exacerbation of psoriasis were included. The four most active lesions were selected in each patient based on the highest degree of redness, induration and expansion in the previous 2 weeks. In all lesions, a cyclic pattern of neutrophil migration was observed, consisting of squirting papillae, transepidermal migration, accumulation in the stratum spinosum, accumulation in the stratum corneum and degeneration of the abscesses. The time interval of a neutrophil‐trafficking cycle was 5–7 days and showed a synchronic time phasing. This study is the first to establish the dynamics and time phasing of neutrophil migration in vivo in psoriatic lesions. Previously reported theories were confirmed by these novel in vivo data. RCM might distinguish between active or chronic psoriatic areas, which might contribute to new insights into the pathogenesis of psoriasis.     

Wavelength effects on contrast observed with reflectance in vivo confocal laser scanning microscopy

Background/purpose: The ability to optically section live biological tissue in vivo with laser light is made possible by confocal laser scanning microscopy (CLSM). In this work, the effects of changing the wavelength of incident light used for CLSM imaging of human skin are reported and analyzed.
Methods: Optical phantoms and the skin of eight human volunteers were imaged using CLSM systems having three different incident light wavelengths (405, 785, and 830 nm).
Results: Qualitative and quantitative differences were observed between images obtained at each wavelength, despite the proximity of the two near infrared 785 and 830 nm wavelengths. Furthermore, the penetration depth achieved with the 405 nm CLSM permitted imaging into the papillary dermis.
Conclusion: The laser wavelength used in CLSM reflectance imaging is important to properly understand and resolve different biological structures within human skin.     

反射式共聚焦显微镜在筛检面部难辨认癣的临床应用

目的:评价反射式共聚焦显微镜(RCM)在诊断浅部真菌病中的应用价值。方法:对46例临床诊断为面部湿疹等但不排除难辨认癣的患者,进行RCM扫描及光学显微镜检查,观察镜下菌丝特征,并与真菌图片相比较。结果:RCM诊断难辨认癣42例(阳性率91.12%),真菌涂片检查阳性40例(阳性率87.83%),差异无统计学意义(P0.05),二者结果具有较好的一致性。结论:RCM是筛检难辨认癣与鉴别皮炎湿疹等皮肤病很好的辅助工具。     

Interferon in the treatment of cutaneous T-cell lymphoma

Interferons are polypeptides with a broad range of in vivo effects that have shown efficacy in cutaneous T-cell lymphoma (CTCL). Particularly useful is alfa interferon (IFN) which, as a single agent, has shown partial remission rates of > 50% and complete responses of > 20%. Side-effects are predictable, generally well tolerated and dose-related. The efficacy of IFN has increased with combination therapy without any significant increase in attendant side-effects. An update on the specifics of the different IFN subtypes, their inherent biologic activity, pharmacokinetics, efficacy and safety in CTCL is presented in this paper.     

New diagnostic methods in dermatopathology: in vivo reflectance confocal microscopy

Reflectance confocal microscopy is a new non‐invasive imaging technique which enables the visualization of upper skin layers in‐vivo at quasi‐histological resolution. Skin changes seen in confocal microscopy in Porokeratosis Mibelli and scabies infection are described in the following two cases.     

Follicular cutaneous T-cell lymphoma: a clinicopathological study of nine cases

Nine patients with follicular cutaneous T-cell lymphoma (CTCL), a recently described variant of lymphoma, are presented. On the basis of clinical manifestations and disease course, three groups of patients were distinguished: (i) two patients with follicular CTCL not associated with conventional lesions of mycosis fungoides (MF) and showing no evolution towards MF in follow-up periods of 3 and 6 years; (ii) one patient with follicular CTCL that evolved into conventional MF within 3 years; (iii) six patients showing conventional MF lesions either before or concurrently with the follicular lesions and thus representing follicular CTCL of the true MF type. The follicular lesions included hair-devoid patches or plaques with spiky hyperkeratotic papules (four patients), keratosis pilaris-like lesions (four), comedo-like lesions (four), follicular papules with alopecia (three) and milia-like lesions (three). Histopathological examination showed perifollicular and intrafollicular lymphocytes, without mucin deposition and with minimal or no involvement of the overlying epidermis. Significant syringotropism was also observed in three cases. Immunohistochemical analysis showed the predominance of CD4 + T cells, deletion of CD7 in some cases, Ki-67 + lymphocytes confined mainly to the follicular epithelium, and expression of keratinocyte intercellular adhesion molecule-1 exclusively in the hair follicle. T-cell receptor gamma gene rearrangement was positive in the one case studied from each group. Different treatment modalities were employed, the most commonly used as monotherapy being phototherapy: psoralen ultraviolet A in four patients, two of whom showed a complete clinical and histopathological remission, and ultraviolet B in one patient, who showed a complete remission (both clinical and histopathological). This study indicates that follicular CTCL is more common than reflected in the literature, has heterogeneous clinical manifestations, and is either an expression of or closely related to MF. The influence of the follicular involvement on the therapeutic response remains to be clarified. However, our therapeutic experience clearly suggests that some patients with follicular CTCL can benefit from phototherapy.     

Concordance between in vivo reflectance confocal microscopy and histology in the evaluation of plaque psoriasis

Background   Psoriasis is a common skin inflammatory disease that affects 2% of the general population. Plaque psoriasis (PP) is its most common variant. In vivo reflectance confocal microscopy (RCM) is a non-invasive, reproducible imaging technique that has proven to give useful information for morphometric evaluation of several inflammatory skin conditions, such as acute contact dermatitis and discoid lupus.
Objective   This study aimed to define the in vivo RCM features of PP and to analyse correlations with histopathologic findings.
Methods   Psoriatic lesions from 36 patients with an established diagnosis of PP were selected for RCM evaluation. Subsequently, a 4-mm punch biopsy specimen of the same imaged areas was taken for histopathologic examination. Normal skin from similar topographic areas of 12 healthy volunteers was evaluated as control samples.
Results   Several RCM features of psoriasis were identified and shown to correlate well with histopathologic evaluation. In > 90% of the cases, RCM revealed hyperkeratosis, parakeratosis, reduced or absent granular layer, papillomatosis and dilated blood vessels. Acanthosis was observed in psoriasis cases, with thickness ranging from 75 to 300 µm, compared to normal skin, which ranged from 60 to 90 µm. The diameter of the dermal papillae was also enlarged (> 100 µm) compared to what was observed in normal skin (> 80 µm).
Conclusion   RCM seems to be useful for microscopic evaluation of PP features, and offers a good correlation with histopathologic findings; it thus constitutes a promising adjuvant tool for non-invasive microscopic diagnosis and for therapeutic follow-up.