In vivo Diagnosis of Primary Cutaneous Amyloidosis —The Role of Reflectance Confocal Microscopy

Abstract

Primary cutaneous amyloidosis (PCA) is a form of localized amyloidosis. It is characterized by the deposition of a fibrillar material in the superficial dermis, without affecting other systems or organs. The diagnosis can be made clinically, but usually a skin biopsy is performed in order to exclude other skin diseases with similar appearance. Reflectance confocal microscopy (RCM) is a novel imaging tool that enables in vivo characterization of various skin changes with a high, quasi-microscopic resolution. This technique might have an important role in the differential diagnosis of cutaneous amyloidosis, by the in vivo assessment of epidermal changes and dermal amyloid deposition. Moreover, it is completely non-invasive and can be safely repeated on the same skin area. However, to date, there is only one published paper presenting the confocal features of primary cutaneous amyloidosis. Hereby, we describe the in vivo RCM features of PCA lesions from a patient with diabetes and correlate them with histologic findings. This strengthens the clinical usefulness of in vivo RCM examination for the non-invasive diagnosis of cutaneous amyloidosis, especially in patients that might associate diseases with impaired wound healing.

Diagnosis of Primary Cutaneous Amyloidosis by Rapid 4,6-Diamidino-2-Phenylindole Staining

“…2c, d). The results were analogous to those reported in literature [7]. DAPI staining revealed that amyloid had oval-shaped or cloud-like blue clumps of different sizes inside the der-mal papillae, which were clearly separated from the surrounding epidermis and dermal tissue (Fig.…”

“…Clinical appearance differs between LA and MA: LA most commonly presents as intensely pruritic papules, sometimes coalescent with lichenification, while MA is characterized by flat hyperpigmented macules that may form a reticular or confluent pattern. These two entities cannot be clearly distinguished on the histological ground [2,6,7]. In addition, symptoms of PCA are subtle and nonspecific, often mimicking manifestations of lichenoid dermatoses, neurodermatitis, and prurigo nodularis.…”

A Systematic Review and Meta-Analysis of the Accuracy of in Vivo Reflectance Confocal Microscopy for the Diagnosis of Primary Basal Cell Carcinoma

“…RCM enables in vivo, non-invasive imaging of the skin layers and cellular structures in a horizontal plane at quasi-histologic resolution [11]. This imaging technique has been widely used in the diagnosis [12,13,14,15,16,17,18,19,20] and therapeutic monitoring [21,22,23,24,25] of skin cancer and inflammatory [26,27,28,29,30] and infectious skin diseases [31,32,33]. Numerous studies have investigated the diagnostic accuracy of in vivo RCM for BCC.…”

Case Report: Diagnosis of Primary Cutaneous Amyloidosis Using Dermoscopy and Reflectance Confocal Microscopy

“…The RCM features of PCA have not been adequately described in the literature. Only two articles have been published to report the RCM features of PCA ( 7 , 8 ). Upon RCM, the characteristics of increased melanin in the basal cell layer, cloud-like agglomerate in the dermal papilla, and melanophage infiltrating in the layer of superficial dermis, which were corresponding to histopathological findings: basal hyper pigmentation, amyloid deposition, pigment incontinence ( 8 ).…”