Multiphoton microscopy assessment of the structure and variability changes of dermal connective tissue in vulvar lichen sclerosus: A pilot study

Abstract

In this article, we offer a novel classification of progressive changes in the connective tissue of dermis in vulvar lichen sclerosus (VLS) relying on quantitative assessment of the second harmonic generation (SHG) signal received from formalin fixed and deparaffinized tissue sections. We formulate criteria for distinguishing four degrees of VLS development: Initial‐Mild‐Moderate‐Severe. Five quantitative characteristics (length and thickness type I Collagen fibers, Mean SHG signal intensity, Skewness and Coherence SHG signal) are used to describe the sequential degradation of connective tissue (changes in the structure, orientation, shape and density of collagen fibers) up to the formation of specific homogeneous masses. Each of the degrees has a characteristic set of quantitatively expressed features. We focus on the identification and description of early, initial changes of the dermis as the least specific. The results obtained by us and the proposed classification of the degrees of the disease can be used to objectify the dynamics of tissue changes during treatment.

Multimodal OCT Control for Early Histological Signs of Vulvar Lichen Sclerosus Recurrence after Systemic PDT: Pilot Study

“…Histological examination of the vulvar skin before PDT showed a pattern characteristic of severe VLS (according to the classification [ 35 ]). In all skin samples, epidermal atrophy was observed with signs of moderate hyperkeratosis (increase in the thickness of the keratin layer) and hypergranulosis (excessive accumulation of keratohyalin granules in cells) and total homogenization of the dermis with edema ( Figure 2 A).…”

“…In all skin samples, epidermal atrophy was observed with signs of moderate hyperkeratosis (increase in the thickness of the keratin layer) and hypergranulosis (excessive accumulation of keratohyalin granules in cells) and total homogenization of the dermis with edema ( Figure 2 A). Homogenization of the dermis is the outcome of tissue destruction during VLS and is structurally a mass of extremely thin collagen fibers [ 35 ]. In the dermis, the number of blood and lymph vessels is drastically reduced ( Figure 2 (A1,A2)).…”

“…The attenuation coefficient OCT signal in the dermis before PDT had low values ( Figure 4 A). From a histological point of view, this is due to both the homogenization of the dermis ( Figure 2 A) and the formation of edema in severe VLS [ 35 ]. A similar effect was observed by other researchers in cerebral edema [ 41 ].…”

“…Patients were referred to PDT based on the decision of the medical council in case of non-effectiveness of standard therapy (unsuccessful use of topical corticosteroids or topical calcineurin inhibitors and no remission within three months). In patients, the clinical degree of severity of VLS was determined according to the classification [ 6 ], and the histological degree of damage to the dermis was determined according to the classification [ 35 ]. A summary of the patients included in the study is presented in Table 2 .…”

Biomaterials for immunomodulation in wound healing

“…Providing structural elasticity, integrity and nutrition to the skin, the dermis constitutes the internal layer [ 15 ]. Additional structural elements in the dermis encompass sebaceous, apocrine and eccrine sweat glands, blood and lymphatic vessels, nerve endings as well as hair follicles extending from the epidermis [ 16 ].…”