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

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, Optical Coherence Tomography, and Multiphoton Microscopy in Inflammatory Skin Disease Diagnosis

BACKGROUND AND OBJECTIVES

Technological advances in medicine have brought about many novel skin imaging devices. This review aims to evaluate the scientific evidence supporting the use of noninvasive optical imaging techniques to aid in the diagnosis and prognosis of inflammatory skin diseases.

STUDY DESIGN/MATERIALS AND METHODS

PubMed and Scopus were searched in September 2020 according to PRISMA guidelines for articles using reflectance confocal microscopy (RCM), optical coherence tomography (OCT), and multiphoton microscopy (MPM) in inflammatory skin diseases, excluding studies monitoring treatment efficacy.

RESULTS

At the time of the study, there were 66 articles that addressed the utilization of noninvasive imaging in interface, spongiotic, psoriasiform, vesiculobullous, and fibrosing/sclerosing inflammatory skin dermatoses: RCM was utilized in 46, OCT in 16, and MPM in 5 articles. RCM was most investigated in psoriasiform dermatoses, whereas OCT and MPM were both most investigated in spongiotic dermatoses, including atopic dermatitis and allergic contact dermatitis.

CONCLUSIONS

There is preliminary evidence to support the diagnostic potential of noninvasive optical imaging techniques in inflammatory skin diseases. Improvements in the devices and further correlation with histology will help broaden their utility. Additional studies are needed to determine the parameters for diagnostic features, disease differentiation, and staging of inflammatory skin conditions. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

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.

Reflectance confocal microscopy may be included as part of the diagnostic algorithm of early-stage mycosis fungoides

INTRODUCTION

Reflectance confocal microscopy (RCM), a noninvasive, real-time technique of computed tomography, has been widely used for pigmentary, inflammatory, and tumor diseases of the skin.

AIM

Our main purpose was to analyze the consistency between pathological and RCM characteristics of early-stage mycosis fungoides (MF) and the utility of RCM in the diagnosis of early-stage MF.

METHODS

According to the RCM features of MF in the early stage, the biopsy sites of 40 cases of suspected MF and 20 cases of chronic inflammatory skin diseases clinically were preliminarily located. Histopathologic and immunohistochemical examinations were performed to make a diagnosis based on the diagnostic algorithm proposed by the International Society for Cutaneous Lymphomas.

RESULTS

Among the 60 patients observed, there were 12 confirming cases of MF, 14 suspecting cases, 6 not completely excluding cases, and 28 eliminating cases according to the diagnostic algorithm, as well as characteristics of RCM were typical in 8 cases, suspected in 16 cases, not excluded in 3 cases, and excluded in 33 cases. The kappa value was 0.769 (P < .01), which means there is a strong consistency between the classification by RCM and the diagnosis algorithm. MF in patch stage and plaque stage (IA to IIB) has typical characteristics of RCM, respectively.

CONCLUSIONS

RCM can be used as an objective and convenient auxiliary means to diagnose early-stage MF and may be included as part of the diagnostic algorithm of early-stage MF.

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.

Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphomas comprise a heterogeneous group of diseases characterized by monoclonal proliferations of T lymphocytes primarily involving skin, modified skin appendages, and some mucosal sites. This article addresses the basic clinical, histologic, and immunohistochemical characteristics of this group of diseases, with additional attention to evolving literature on dermoscopy, reflectance confocal microscopy, flow cytometry, and molecular data that may increasingly be applied to diagnostic and therapeutic algorithms in these diseases. Select unusual phenotypes or diagnostic examples of classic phenotypes are demonstrated, and flags for consideration while making a pathologic diagnosis of cutaneous T-cell lymphoma are suggested.

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.

Confocal microscopy patterns in nonmelanoma skin cancer and clinical applications

Reflectance confocal microscopy is currently the most promising noninvasive diagnostic tool for studying cutaneous structures between the stratum corneum and the superficial reticular dermis. This tool gives real-time images parallel to the skin surface; the microscopic resolution is similar to that of conventional histology. Numerous studies have identified the main confocal features of various inflammatory skin diseases and tumors, demonstrating the good correlation of these features with certain dermatoscopic patterns and histologic findings. Confocal patterns and diagnostic algorithms have been shown to have high sensitivity and specificity in melanoma and nonmelanoma skin cancer. Possible present and future applications of this noninvasive technology are wide ranging and reach beyond its use in noninvasive diagnosis. This tool can also be used, for example, to evaluate dynamic skin processes that occur after UV exposure or to assess tumor response to noninvasive treatments such as photodynamic therapy. We explain the characteristic confocal features found in the main nonmelanoma skin tumors and discuss possible applications for this novel diagnostic technique in routine dermatology practice.

Reflectance confocal microscopy for the characterization of mycosis fungoides and correlation with histology: a pilot study

BACKGROUND

Mycosis fungoides (MF) is cutaneous lymphoma of the T-cell lineage. MF is a diagnostic challenge. In vivo reflectance confocal microscopy (RCM) reproducible imaging technique already reported to be useful in the diagnosis of skin diseases. The aims of our study were to define RCM features of MF and to evaluate its feasibility in biopsy site selection.

METHODS

Each lesion was selected for RCM evaluation from 10 patients with an established diagnosis of MF. Subsequently, a biopsy of the same areas evaluated with RCM was rendered for histopathological examination.

RESULTS

A series of RCM features of MF was identified and shown to correlate well with histopathological evaluation. We could find hyperkeratosis in five patients (10 : 50%); disarray of honeycomb of stratum spinosum in three patients (10 : 30%). In 10 patients (10 : 100%) of the MF, we could find that dermal papillary rings were weak reflected light; round to oval cells diffusely widespread throughout the epidermis and in the papillary dermis, infiltration of inflammatory cells in superficial dermis. Two (10 : 20%) of them can find vesicle area opaca in plaque stage MF, filled with monomorphous weakly refractile oval to round cells.

CONCLUSION

The utility of RCM as a diagnostic tool for MF awaits further evaluation, although it appears to be promising for biopsy site selection.

Concordance between in vivo reflectance confocal microscopy and optical histology of lymphomatoid papulosis

BACKGROUND

Lymphomatoid papulosis is a primary cutaneous CD30+ T-cell lymphoma clinically characterized by a benign, chronic, recurrent course with self-limited papulo-nodular skin lesion eruption. In vivo Reflectance Confocal Microscopy is a non-invasive technique for real-time imaging of the superficial layers of the skin down to the superficial dermis with cellular-level resolution close to conventional histopathology. RCM has been previously reported to be useful in the in vivo evaluation of inflammatory diseases, skin tumours and also cutaneous lymphomas. Only two articles have been published on cutaneous lymphomas and none detailing confocal features of LyP. The aim of this manuscript was to describe the confocal features of LyP and their histological correlation to evaluate the possible application of this non-invasive tool in this T-cell lymphoma subtype clinical management.

METHODS

Five patients with histological diagnosis of LyP were imaged with RCM, followed by a skin biopsy on a clinically selected lesion.

RESULTS

High grade of correspondence between RCM and histopathology of LyP was observed, disclosing the potential rule of RCM at least for biopsy site selection.

CONCLUSION

Future studies on RCM for LyP vs. other cutaneous T-cells lymphomas and inflammatory skin diseases are needed to assess specificity and sensibility of our preliminary data.