Pseudoxanthoma-like late-onset focal dermal elastosis

Late-onset focal dermal elastosis: report of a case and review of the literature

Late-onset focal dermal elastosis is a rare cutaneous condition classified within the disorders of increased dermal elastic tissue. It is characterized clinically by multiple papules with predilection for the neck and other flexures, without systemic alterations, and histologically by focally increased elastic fibers in the reticular dermis. Several elastic tissue disorders share a similar clinical presentation in the skin. Distinction of late-onset focal dermal elastosis and other pseudoxanthoma elasticum mimickers from pseudoxanthoma elasticum is critical, as they are not associated to systemic lesions. We report here on a case of late-onset focal dermal elastosis and review the scientific literature on this unusual condition.

Focal Dermal Elastosis: A Proposed Update to the Nomenclature

Late-onset focal dermal elastosis is a clinical mimic of pseudoxanthoma elasticum that lacks associations with systemic disease. Although initial reports asserted that the disorder occurs only in the elderly, a growing body of case reports document cases in patients as young as 39 years. We present a case of a 59-year-old woman with this disorder. To reflect the broad age range of patients affected by this disorder, we propose the term "focal dermal elastosis."

A Case Series of Pseudoxanthoma Elasticum-like Disorders

Pseudoxanthoma elasticum (PXE)-like papillary dermal elastolysis and focal dermal elastosis are acquired noninflammatory elastic tissue disorders. The skin lesions clinically resemble PXE without systemic involvement. We report the clinicopathological features of five cases and discuss the pathogenesis and differential diagnosis. Increased awareness of this newly described entity will broaden the differential diagnosis for dermatologists when encountering a similar case scenario.

Pseudoxanthoma elasticum and skin: Clinical manifestations, histopathology, pathomechanism, perspectives of treatment

Pseudoxantoma elasticum (PXE), also known as Groenblad-Strandberg syndrome, is a rare heritable disease with an estimated prevalence of 1:50,000 in the general population. PXE is considered a prototype of multisystem ectopic mineralization disorders and it is characterized by aberrant mineralization of soft connective tissue with degeneration of the elastic fibers, involving primarily the eyes, the cardiovascular system, and the skin. Cutaneous lesions consist of small, asymptomatic, yellowish papules or larger coalescent plaques, typically located on the neck and the flexural areas. PXE is caused by mutations in the ABCC6 (ATP-binding cassette subfamily C member 6) gene that encodes a transmembrane ATP binding efflux transporter, normally expressed in the liver and the kidney; however, the exact mechanism of ectopic mineralization remains largely unknown. The histological examination of cutaneous lesions, revealing accumulation of pleomorphic elastic structures in middermis, is essential for the definitive diagnosis of PXE, excluding PXE-like conditions. PXE is currently an intractable disease; although the cutaneous findings primarily present a cosmetic problem, they signify the risk for development of ocular and cardiovascular complications associated with considerable morbidity and mortality. The purpose of this review is to present a comprehensive overview of this rare form of hereditary connective tissue disorders, focus on the pathogenesis, the clinical manifestation, and the differential diagnosis of PXE. Emphasis is also placed on the management of cutaneous lesions and treatment perspectives of PXE.

A quantitative approach to histopathological dissection of elastin-related disorders using multiphoton microscopy

BACKGROUND

Multiphoton microscopy (MPM) is a novel imaging technology that has recently become applicable for diagnostic purposes. The use of (near) infrared light in MPM allows for deep tissue imaging. In addition, this modality exploits the autofluorescent nature of extracellular matrix fibres within the skin.

OBJECTIVES

To quantitate the structure and abundance of elastic fibres in human dermis in three dimensions utilizing autofluorescent signals generated by MPM for the objective examination of elastin-related skin disorders.

METHODS

Cross-sections of skin samples from elastin-related disorders were analysed by MPM and correlated to histopathology. In situ visualization of elastic fibres by MPM was conducted by en face imaging of ex vivo skin samples through the intact epidermis. Image analysis software was used to quantify elastic fibres in three dimensions.

RESULTS

Based on the MPM-detected elastin-specific autofluorescence, we developed the Dermal Elastin Morphology Index (DEMI), calculated as the ratio of elastic fibre surface area and volume. This enabled objective three-dimensional quantification of elastic fibres. Quantitative scoring of sun-damaged skin using DEMI correlated with qualitative histopathological grading of the severity of solar elastosis. Furthermore, this approach was applied to changes in elastic fibre architecture in other disorders, such as pseudoxanthoma elasticum (PXE), PXE-like syndrome, elastofibroma, focal dermal elastosis, anetoderma, mid-dermal elastolysis and striae distensae. We imaged elastic fibres in intact ex vivo skin imaged en face through the epidermis, indicating that this approach could be used in vivo.

CONCLUSIONS

MPM has the potential for noninvasive in vivo visualization of elastic fibres in the dermis with near histological resolution. DEMI allows objective assessment of elastic fibres to support diagnosis and monitoring of disease progress or therapy of elastin-related skin disorders.

PSEUDOXANTHOMA ELASTICUM: DIAGNOSTIC FEATURES, CLASSIFICATION, AND TREATMENT OPTIONS

INTRODUCTION

Pseudoxanthoma elasticum (PXE), a multisystem orphan disease, clinically affects the skin, the eyes, and the cardiovascular system with considerable morbidity and mortality. The clinical manifestations reflect the underlying pathology consisting of ectopic mineralization of peripheral connective tissues.

AREAS COVERED

The diagnostic criteria of PXE include characteristic clinical findings, together with histopathology of accumulation of pleiomorphic elastic structures in the dermis with progressive mineralization, and the presence of mutations in the ABCC6 gene. PXE-like cutaneous changes can also be encountered in other ectopic mineralization disorders, including generalized arterial calcification of infancy (GACI) caused by mutations in the ENPP1 gene. In some cases, overlapping clinical features of PXE/GACI, associated with mutations either in ABCC6 or ENPP1, have been noted. PXE demonstrates considerable inter- and intrafamilial heterogeneity, and consequently, accurate diagnosis is required for appropriate classification with prognostic implications. There is no effective and specific treatment for the systemic manifestations of PXE, but effective therapies to counteract the ocular complications are in current clinical use.

EXPERT OPINION

A number of observations in the murine model, the Abcc6^-/- mouse, have indicated that the mineral composition of diet, particularly the magnesium content, can influence the severity of the mineralization phenotype. These observations suggest that appropriate dietary interventions, coupled with lifestyle modifications, including smoking cessation, might alleviate the symptoms and improve the quality of life of individuals affected with this, currently intractable, orphan disease.

Late-onset focal dermal elastosis: an uncommon mimicker of pseudoxanthoma elasticum

Late-onset focal dermal elastosis is a rare disorder that presents clinically with the development of small white-to-yellow papules simulating pseudoxanthoma elasticum (PXE) in otherwise healthy adults in the seventh through ninth decades. It is characterized histopathologically by foci of increased normal-appearing elastic tissue in the reticular dermis. The disorder lacks any of the systemic complications of PXE and clinically resembles several other elastic tissue disorders that mimic PXE. We report two cases of late-onset focal dermal elastosis. The first is of a 75-year-old female who presented with symmetrically distributed, 2-5 mm white-to-yellow, discrete and coalescing, non-follicular papules on the posterolateral neck, anterior chest and axillae. The second case involves a 39-year-old female who presented with asymptomatic flesh-colored lesions on the posterior neck, back, antecubital and popliteal fossae, thighs, forearms and wrists. Skin biopsies in each case revealed aggregates of elastic fibers in the reticular dermis without calcification. The differential diagnosis of clinical and histopathologic imitators of PXE is discussed.

Familial acral localized late-onset focal dermal elastosis

Late-onset focal dermal elastosis is a rare disorder of elastic tissue, characterized by a local accumulation of elastic fibers in the mid and deep reticular dermis. This disorder occurs mainly in elderly people and consists of multiple yellow papules that are typically distributed on the sides of the neck and flexural areas, closely resembling pseudoxanthoma elasticum from the clinical point of view. We report 2 sisters who have presented with a 20-year history of multiple yellow papules, mainly located on the dorsum of their hands. They also had few lesions of similar morphology scattered on the anterior aspects of their wrists, thighs, and lower abdomen. Histopathologic study demonstrated a focal increase in thick, interlacing elastic fibers in the mid and deep reticular dermis. The most striking features of our cases were the early age of clinical presentation, the familial involvement, and the predominantly acral distribution of the lesions.

Histopathology of pseudoxanthoma elasticum and related disorders: histological hallmarks and diagnostic clues

Among ectopic mineralization disorders, pseudoxanthoma elasticum (PXE)-a rare genodermatosis associated with ocular and cardiovascular manifestations-is considered a paradigm disease. The symptoms of PXE are the result of mineralization and fragmentation of elastic fibers, the exact pathophysiology of which is incompletely understood. Though molecular analysis of the causal gene, ABCC6, has a high mutation uptake, a skin biopsy has until now been considered the golden standard to confirm the clinical diagnosis. Although the histological hallmarks of PXE are rather specific, several other diseases-particularly those affecting the skin-can present with clinical and/or histological characteristics identical to or highly resemblant of PXE. In this paper, we will summarize the histopathological features of PXE together with those of disorders that are most frequently considered in the differential diagnosis of PXE.

[Papillary dermal elastolysis similar to pseudoxanthoma elasticum]

Papillary dermal elastolysis similar to pseudoxanthoma elasticum is an elastolytic disorder characterized by cutaneous lesions on the neck and in the supraclavicular region that are clinically similar to pseudoxanthoma elasticum, with no systemic complications. The histological examination shows a loss of elastic fibers in the papillary dermis. We report a case in a 76-year-old woman with typical lesions on the neck.