Preliminary evaluation of in vivo reflectance confocal microscopy features of discoid lupus erythematosus

Consistency and distribution of reflectance confocal microscopy features for diagnosis of cutaneous T cell lymphoma

Reflectance confocal microscopy (RCM) represents a noninvasive imaging technique that has previously been used for characterization of mycosis fungoides (MF) in a pilot study. We aimed to test the applicability of RCM for diagnosis and differential diagnosis of MF in a clinical study. A total of 39 test sites of 15 patients with a biopsy-proven diagnosis of either MF, parapsoriasis, Sézary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi(2) analysis were applied to test the concordance between investigators and the distribution of RCM features, respectively. For selected parameters, the Cochran analysis showed good concordance between investigators. Inter-observer reproducibility was highest for junctional atypical lymphocytes, architectural disarray, and spongiosis. Similarly, Chi(2) analysis demonstrated that selected features were present at particularly high frequency in individual skin diseases, with values ranging from 73% to 100% of all examined cases.

In vivo reflectance confocal microscopy: usefulness for diagnosing hair diseases

BACKGROUND

Reflectance confocal laser scanning microscopy (R-CSLM) is a new diagnostic technique which allows visualization of "optical intersections" within the epidermis and superficial layers of the dermis. Outlines of cells and their architecture are imaged and may be analyzed both horizontally and vertically to the skin surface. The method proved useful in early melanoma detection. We evaluated the potential usefulness of this method in a short series of patients with hair diseases.

MAIN OBSERVATIONS

Two healthy persons and 6 patients with hair diseases (1 with alopecia areata, 1 with androgenic alopecia and 4 with genetic hair shaft abnormalities) were examined with the use of Vivascope 1500. In all patients one scalp location and one location in the mid forearm were evaluated. R-CSLM examination gave in all cases high quality images of the hair shaft intersections, at 1µm intervals, which allowed detailed analysis of the hair structure. Hair follicles could be partly visualized at a depth of up to 200µm, which allowed analysis of only superficial parts of the hair follicles. An additional hurdle was bright reflection within the follicular ostia, which decreased the perception of details in these images. Hair could be best visualized, when analyzed on flat surfaces. Receiving good quality images from convex surfaces on the scalp required additional effort from the patient (to not move) and from the physician (to obtain best possible fit of the "optic window" to the scalp).

CONCLUSIONS

These preliminary data show that R-CSLM may develop into a valuable tool in evaluation of hair shaft diseases. Further development is needed to apply this technique in abnormalities of the hair follicle and the perifollicular area.

Confocal microscopic features of scarring alopecia: preliminary report

BACKGROUND

Lichen planopilaris (LPP) and discoid lupus erythematosus (DLE) are the most common causes of lymphocytic primary cicatricial alopecia. The management of scarring alopecia can be difficult. The combination of clinical, dermoscopy and reflectance confocal microscopy (RCM), a noninvasive, high-resolution imaging technique, examinations have already been demonstrated to be useful for choosing the correct biopsy site in patients with inflammatory skin disease and obtaining microscopic diagnostic criteria.

OBJECTIVES

We evaluated the usefulness in practice of RCM for the identification of criteria for LPP and DLE involving the scalp and their management during therapeutic follow-up.

METHODS

Seven white patients with a previously established histological diagnosis of DLE (three) and LPP (four), were included in the study. RCM criteria for primary scarring alopecia were selected: epidermal disarray, spongiosis, exocytosis of inflammatory cells in the epidermis, interface dermatitis, peri- and intra-adnexal infiltration of inflammatory cells, dilated vessels in the dermis, dermal infiltration of inflammatory cells and melanophages and dermal sclerosis. All patients were followed up using RCM during the treatment. During follow-up the RCM evolution of the epidermal, junctional and dermal inflammation were evaluated.

RESULTS

A series of RCM features of scalp LPP and DLE were identified that show correlation with the histopathological evaluation. During the treatment follow-up of the cases RCM was shown to be sensitive for the identification of therapeutic response.

CONCLUSION

In our preliminary study the effective usefulness of RCM for the diagnosis of scarring alopecia and follow-up seemed to be evident. Moreover, RCM seems to be also promising for differential diagnosis between the different entities.

In vivo reflectance confocal microscopy: automated diagnostic image analysis of melanocytic skin tumours

BACKGROUND

In vivo reflectance confocal microscopy (RCM) has been shown to be a valuable imaging tool in the diagnosis of melanocytic skin tumours. However, diagnostic image analysis performed by automated systems is to date quite rare.

OBJECTIVES

In this study, we investigated the applicability of an automated image analysis system using a machine learning algorithm on diagnostic discrimination of benign and malignant melanocytic skin tumours in RCM.

METHODS

Overall, 16,269 RCM tumour images were evaluated. Image analysis was based on features of the wavelet transform. A learning set of 6147 images was used to establish a classification tree algorithm and an independent test set of 10, 122 images was applied to validate the tree model (grouping method 1). Additionally, randomly generated 'new' learning and test sets, tumour images only and different skin layers were evaluated (grouping method 2, 3 and 4).

RESULTS

  The classification tree analysis correctly classified 93.60% of the melanoma and 90.40% of the nevi images of the learning set. When the classification tree was applied to the independent test set 46.71 ± 19.97% (range 7.81-83.87%) of the tumour images in benign melanocytic skin lesions were classified as 'malignant', in contrast to 55.68 ± 14.58% (range 30.65-83.59%; t-test: P < 0.036) in malignant melanocytic skin lesions (grouping method 1). Further investigations could not improve the results significantly (grouping method 2, 3 and 4).

CONCLUSIONS

The automated RCM image analysis procedure holds promise for further investigations. However, to date our system cannot be applied to routine skin tumour screening.

Reflectance confocal microscopy of facial lentigo maligna and lentigo maligna melanoma: a preliminary study

BACKGROUND

Facial lentigo maligna (LM) and lentigo maligna melanoma (LMM) may be difficult to diagnose clinically and dermoscopically. Reflectance confocal microscopy (RCM) enables the in vivo assessment of equivocal skin lesions at a cellular level.

OBJECTIVES

To assess cytomorphological and architectural RCM features of facial LM/LMM.

METHODS

Four women and eight men aged 58-88 years presenting with facial skin lesions suspicious of LM/LMM were included. In total, 17 lesion areas were imaged by RCM before biopsy. The histopathological diagnosis of LM was made in 15 areas; the other two were diagnosed as early LMM.

RESULTS

A focal increase of atypical melanocytes and nests surrounding adnexal openings, sheets of mainly dendritic melanocytes, cord-like rete ridges at the dermoepidermal junction (DEJ) and an infiltration of adnexal structures by atypical melanocytes were found to be characteristic RCM features of facial LM/LMM. Areas with a focal increase of atypical melanocytes and nests surrounding adnexal openings were observed at the basal layer in three cases. The remaining cases displayed these changes at suprabasal layers above sheets of mainly dendritic melanocytes. Cord-like rete ridges at the DEJ and an infiltration of adnexal structures by atypical melanocytes were observed in all cases. Previously described criteria for RCM diagnosis of melanoma, such as epidermal disarray, pleomorphism of melanocytes and pagetoid spreading of atypical melanocytes, were additionally observed.

CONCLUSIONS

We observed a reproducible set of RCM criteria in this case series of facial LM/LMM.

Skin imaging with reflectance confocal microscopy

Confocal microscopy is a new imaging modality for noninvasive real-time tissue imaging with high resolution and contrast comparable with conventional histology. Application of this technology to skin imaging during the last decade has been an exciting advance in dermatology, allowing a virtual widow into living skin without the need for a conventional biopsy or histologic processing of tissue. High-resolution noninvasive skin imaging with confocal microscopy has potential broad applications in the clinical and research arenas, including differentiating between benign and malignant skin lesions, tumor margin mapping, monitoring response to medical or surgical treatments, and pathophysiologic study of inflammatory processes.