Reflectance confocal microscopy of pigmented Bowen's disease: a case series of difficult to diagnose lesions

Pigmented Bowen's disease is a rare variant of in situ squamous skin cell carcinoma. It mainly affects patients between 60 and 70 years of age. Its clinical features include well-demarcated, pigmented plaque arising in photo-exposed areas of the body. The best-characterized feature of the disease by histological examination is the presence of atypical keratinocytes, hyperpigmentation of the epidermis with trans-epidermal elimination of melanin and dermal melanophages. Precise diagnosis is often difficult, both clinically and dermoscopically, as Bowen's disease is often mistaken with keratinocyte tumors such as solar lentigines, seborrheic keratosis, Bowenoid papulosis, pigmented basal cell carcinoma, pigmented actinic keratosis; or even melanocytic lesions such as melanocytic nevus, pigmented epithelioid melanocytoma, and melanoma. Precise diagnosis often requires biopsy and histopathological examination of the tissue. Reflectance confocal microscopy is a noninvasive technique to diagnose pigmented skin lesions. To date, not much data are available regarding its use in the diagnosis of pigmented Bowen's disease. Herein, we report a well-represented case series of pigmented Bowen's disease imaged using dermoscopy and reflectance confocal microscopy

Biotic and inorganic control on travertine deposition at Bullicame 3 spring (Viterbo, Italy): A multidisciplinary approach

A multidisciplinary characterization of an active thermal spring in central Italy has been undertaken with the aim of (i) ascertaining whether microbiological activity plays a relevant role in hot-depositing travertines and (ii) establishing an experimental protocol able to identify similar effects in fossil travertines. Water, gas, and travertine samples were investigated by chemical (ICP/MS, SEM/EDS), physical (DTA-DTG), isotopic (δ18O, δD, and δ13C), mineralogical (XRPD), and spectroscopic (EPR) techniques. Twenty-four samples (three for each phase) were collected every 5°C temperature drop, along a ∼100m long artificial channel near Viterbo (Bullicame 3, Latium, central Italy). A microbiological characterization was carried out in parallel, sampling the channel every 10°C temperature drop. The Bullicame 3 system is revealed to be composed of two markedly different subsystems: a water/gas interface, where a kinetically fast exchange allows equilibrium of components both in water and in gases; a solid/water interface, where travertine precipitation occurs, influenced by microbiological activity. A peculiar lattice shrinking of calcite was identified, as well as an anomalous value of the zero-field splitting parameter from the EPR measurements. The interpretation of these anomalies is confirmed by the identification of calcifying cyanobacteria throughout the channel path. Our results point out that microbiological activity can play a significant role in travertine deposition from hot springs. Furthermore, the proposed approach, representing a tool to identify crystal chemical remnants of past microbiological activity, could be applicable to fossil travertines