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

Non-invasive Skin Imaging in Cutaneous Lymphomas

The diagnosis of cutaneous lymphomas is challenging and requires skin tissue for histology and immunophenotyping using immunohistochemistry and molecular studies. In recent years, the role of non-invasive imaging techniques has been described as part of the clinical assessment of cutaneous lymphoma lesions. Imaging modalities such as dermoscopy, reflectance confocal microscopy (RCM), and high frequency ultrasound (HFUS) have been shown to be very valuable in raising the clinical suspicion for lymphomas of the skin, and in distinguishing cutaneous lymphomas from inflammatory dermatoses such as lupus, psoriasis, or eczema. These non-invasive methods can be used to direct the clinician to the optimal biopsy site to maximize the histopathological results and minimize false negatives. These methods also have a potential place in monitoring treatment response. In this review we present a concise summary of the dermoscopic imaging, RCM, and HFUS features seen in cutaneous T-cell lymphomas (CTCL) and B-cell lymphomas (CBCL).

Reflectance confocal microscopy role in mycosis fungoides follow-up

BACKGROUND

Reflectance confocal microscopy (RCM) is a useful tool for many skin cancers, allowing non-invasive evaluation over time and identifying areas of active disease. Its role to follow-up mycosis fungoides (MF) patients has not yet been evaluated.

OBJECTIVE

To assess the level of agreement between RCM and histopathology and to develop a RCM checklist that could help monitoring MF patients.

METHOD

Prospective study in a cutaneous lymphoma clinic of a tertiary hospital in Australia. RCM and biopsies were performed on the same area at baseline, before commencing or changing treatment, and at 6 months after starting treatment. Normal skin sites were also analysed and acted as controls. RCM features and histopathological findings were blindly evaluated by the confocalist and pathologist. Correlation between RCM and histology was measured by overall per cent of agreement (OPA), kappa and ROC curves. Additionally, RCM images before and after treatment were assessed blinded from clinical information and correlated to clinical assessment.

RESULTS

Thirty-eight MF lesions were included. Nineteen of these 38 were re-assessed by RCM 6 months later. Fifty biopsies were performed (38 at baseline and 12 after 6 months). The combination of four RCM features corresponding to Pautrier's microabscess, epidermal and junctional lymphocytes and interface dermatitis formed the RCM checklist for MF that predicted the severity of disease with AUC of 0.95 (P = .003).

CONCLUSION

Reflectance confocal microscopy can assess activity within a lesion and over time and assist in the clinical management of patients with MF.

Features of classic lichen planopilaris and frontal fibrosing alopecia in reflectance confocal microscopy: A preliminary study

BACKGROUND

Classic lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) are primary lymphocytic cicatricial alopecia. In patients with ambiguous clinical presentation, reflectance confocal microscopy (RCM) a new noninvasive skin imaging technique, could be a helpful diagnostic tool. The aim of our study was to describe the characteristic features of classic LPP and FFA using RCM.

MATERIALS AND METHODS

Ten patients with classic lichen planopilaris and two with frontal fibrosing alopecia were examined with RCM.

RESULTS

Lichenoid inflammatory infiltrate around the hair follicle was observed in three cases of classic LPP and FFA (3/12; 25.0%). Extensive perifollicular fibrosis was seen in nine patients (9/12; 75.0%) with classic LPP and FFA. An increased number of white, ill-defined, coarse dermal fibers at the level of the superficial dermis were visible in seven cases (7/12; 58.3%). Moreover, dilated blood vessels were present in seven patients with classic LPP and FFA (7/12; 58.3%).

CONCLUSION

Summing up, reflectance confocal microscopy allows to visualize major key diagnostic features of classic lichen planopilaris and frontal fibrosing alopecia in the real time. The value of RCM examination in scarring alopecia needs to be further evaluated, but it appears to be a useful adjuvant tool for the initial diagnosis of classic LPP and FFA.

In Vivo Reflectance Confocal Microscopy in General Dermatology: How to Choose the Right Indication

Reflectance confocal microscopy (RCM) is a high-resolution, noninvasive imaging technique being increasingly used as an aid to diagnosis in the dermatology setting. RCM is applied in the diagnosis of both melanoma and nonmelanoma skin tumors, but also in the interpretation and management of inflammatory skin diseases. Two different devices with different designs for specific indications are available in the market: a static and a handheld probe. Several clinical presentations of the lesion could affect the examination, such as the presence of ulceration or hyperkeratosis; moreover, the anatomical site can drive the probe selection as well as the effective indication to RCM examination. In this review article, indications for the use of RCM are described in detail with a schematic approach for practical purposes.

Systematic review and proposal of an in vivo reflectance confocal microscopy assessment tool for cutaneous lymphoma

BACKGROUND

Reflectance confocal microscopy (RCM) is a non-invasive imaging technique that provides dynamic information and allows in vivo monitoring, with excellent histologic correlation. In the last decade, the use of RCM for cutaneous T-cell lymphomas (CTCL) has been reported. CTCL may require multiple biopsies for diagnosis due to its equivocal clinical presentation. RCM was described as a possible tool to help determine the best site for skin biopsy. This study aims to systematically review all RCM features reported in literature for CTCL.

METHOD

A systematic literature search concerning CTCL evaluated by RCM was performed in eight electronic databases until May 2019 following PRISMA-DTA quality assessment.

RESULTS

Eighteen RCM features were described in patients with CTCL. The most frequent were: interface dermatitis (89%), epidermal lymphocytes (82%), epidermal architectural disarray (81%), and vesicle-like structure (Pautrier microabscess) (51%).

CONCLUSION

In order to establish comparable parameters among the studies identified, we proposed descriptors for CTCL features and a grading system to quantify them. This will facilitate to define the role of RCM in the diagnosis and monitoring of CTCL patients.

Current and future applications of confocal laser scanning microscopy imaging in skin oncology

Confocal laser scanning microscopy (CLSM) is a modern imaging technique that enables the in vivo or ex vivo characterization of skin lesions located in the epidermis and superficial dermis with a high quasi-microscopic resolution. Currently, it is considered to be the most promising imaging tool for the evaluation of superficial skin tumors. The in vivo mode adds the advantage of noninvasive, dynamic, in real-time assessment of the tumor associated vasculature and inflammation. It offers the possibility to repeatedly examine the same skin area without causing any damage and to monitor disease progression and treatment outcome. Furthermore, this novel technology allows the evaluation of the entire lesion and can be used to guide biopsies and to define tumor margins before surgical excision or other invasive therapies. CLSM diagnostic features may differentiate between the various histologic subtypes of skin tumors and therefore helps in choosing the best therapeutic approach. In this study, we present the CLSM characteristic features of the most common melanocytic and non-melanocytic skin tumors, as well as future possible CLSM applications in the study of experimental skin tumorigenesis on animal models.

Reflectance Confocal Microscopy as New Diagnostic Tool in Folliculotropic Mycosis Fungoides

We present a case of folliculotropic mycosis fungoides (FMF), a variant of cutaneous T-cell lymphoma which particularly affects hair follicles. FMF can imitate a wide variety of otherwise benign dermatoses, so it poses major diagnostic obstacles both for the dermatologist as well as the dermatopathologist. In our case, in vivo reflectance confocal microscopy (RCM) was very important for guiding the skin biopsy site selection. For this reason, RCM can reduce the number of unsuccessful histopathological examinations and increase the diagnostic accuracy for different skin dermatoses.

Reflectance confocal microscopy features of mycosis fungoides and Sézary syndrome: correlation with histopathologic and T-cell receptor rearrangement studies

BACKGROUND

Mycosis fungoides/Sézary syndrome (MF/SS) often requires multiple skin biopsies for definitive diagnosis. In vivo reflectance confocal microscopy (RCM) visualizes high-resolution cellular detail of the skin. The objective of this study is to evaluate the morphologic features of MF/SS using RCM and to correlate RCM features with histopathology and T-cell receptor (TCR) gene rearrangement studies.

METHODS

A cohort of patients with active/recurrent or suspicious MF/SS disease was prospectively recruited for RCM imaging and histopathologic/RCM images were evaluated. Statistical analyses were performed to identify unique RCM features and to correlate RCM features with histopathologic findings and TCR rearrangement studies.

RESULTS

Eighty-three lesions were evaluated. Correlation between RCM and histopathology was moderate for all relatable features (κ = 0.41, p<0.001), almost perfect for intraepidermal atypical lymphocytes [prevalence and bias-adjusted kappa (PABAK) = 0.90], and fair for Pautrier collections (κ = 0.32, p = 0.03). Lesions with Pautrier collections identified by RCM were significantly more likely to show TCR clonality (p = 0.04) and diagnostic features of MF/SS on histopathology (p = 0.03).

CONCLUSIONS

Our study captures morphologic RCM criteria for a variety of skin lesions. Pautrier collections visualized by RCM are associated with improved histopathologic diagnosis and detection of TCR gene clonality. Although further studies are needed to validate the diagnostic implications of RCM for MF/SS, our study highlights the potential utility of RCM.