Atypical Honeycomb Research Articles

Reflectance Confocal Microscopy - Real-Time In Vivo Imaging of Basal and Squamous Cell Carcinomas

Reflectance and confocal microscopy (RCM) is an in vivo non-invasive imaging tool that captures horizontal images of the epidermis and superficial dermis at nearly the same resolution of routine histopathology. Due to the overlying superficial scaling, RCM characterization of squamous cell carcinomas (SCCs) and associated keratinizing tumors is difficult to visualize due to the obscure appearance of underlying structures. To date, although an increasing frequency of abnormal RCM features are observed across the spectrum, only a few authors have described the features of SCCs. One recent study suggested a disarranged and atypical honeycomb pattern along with round nucleated cells within the spinous/granular layers and round vessels traversing through dermal papilla as key features of SCC. Meanwhile several RCM features have been linked to basal cell carcinomas (BCCs) regardless of type including: Variable architectural disarray of the epidermis A uniform pattern of elongated monomorphic nuclei polarized along the same axis Abundant vessels with prominent tortuosity Mononuclear inflammatory infiltrate admixed with carcinoid basal cells Tightly packed cells in the papillary dermis with a nodular/cord-like growth pattern Palisading tumor cell nuclei Peri-tumoral dark cleft-like spaces representing mucinous edema The presence of bright dendritic cells and melanophages in pigmented BCC Our objective is to identify and describe characteristic RCM findings of SCCs and BCCs by imaging biopsy-proven lesions and reviewing the most recent literature. We will also explain how these features may facilitate diagnosis and recognize future trends for research. Applications of RCM criteria concerning surgical management of these lesions will also be discussed.

Non‐invasive diagnosis and monitoring of actinic cheilitis with reflectance confocal microscopy

Actinic cheilitis (AC) represents the equivalent of actinic keratosis on the lip. Various treatment modalities are available and the efficacy of diclofenac in hyaluronic acid has recently been described. Reflectance confocal microscopy (RCM) is a non-invasive imaging technique which has recently been applied for the diagnosis of actinic keratoses. Herein, we describe the applicability of RCM for the diagnosis of AC and for monitoring of treatment response of AC to diclofenac in hyaluronic acid. Ten Caucasian patients with clinical suspicion for AC were included in this study. To obtain a non-invasive diagnosis, RCM was performed at baseline, followed by biopsy and respective confocal-histopathological correlation. Six patients with a histological diagnosis of AC were treated with diclofenac in hyaluronic acid, whereby monitoring was performed by RCM. Reflectance confocal microscopy was able to correctly identify 6/7 cases of AC and 3/3 cases of benign lesions. The most important RCM criteria for diagnosis of AC were cellular atypia at the stratum spinosum and granulosum with atypical honeycomb pattern. One patient with AC was misclassified as inflammatory cheilitis by RCM as it showed marked inflammatory response and lacked clear signs of cellular atypia on RCM imaging. Following topical treatment with diclofenac gel, 5/6 patients (83%) showed a good treatment response with regression of dysplasia on consecutive RCM examination. Reflectance confocal microscopy is a promising tool for the non-invasive diagnosis and monitoring of actinic cheilitis. However, marked inflammation represents a potential diagnostic pitfall. In this regard, biopsy should be performed in doubtful cases.

Reflectance Confocal Microscopy Criteria for Squamous Cell Carcinomas and Actinic Keratoses

To identify criteria for the diagnosis of squamous cell carcinoma (SCC) and actinic keratosis (AK) by in vivo reflectance confocal microscopy (RCM). Prospective RCM imaging of lesions suspected clinically and/or dermoscopically to be SCC or AK, followed by RCM assessment of the biopsy-proven SCCs and AKs. Private skin cancer clinic, Plantation, Florida. Patients A total of 38 lesions in 24 patients were assessed, including 7 AKs, 25 SCCs in situ, 3 invasive SCCs, and 3 keratoacanthomas. Interventions Prior to undergoing biopsy, all lesions were assessed by RCM. Mosaic RCM images at the stratum corneum level revealed scale in 29 SCCs (95%) and in all 7 AKs. Polygonal nucleated cells at the stratum corneum were seen in 3 SCCs (10%) and 1 AK (14%). All 38 cases displayed an atypical honeycomb and/or a disarranged pattern of the spinous-granular layer of the epidermis; round nucleated cells were seen in the spinous-granular layer in 20 SCCs (65%) and 1 AK (14%). Round blood vessels in the superficial dermis were seen in 28 SCCs (90%) and 5 AKs (72%). An increasing frequency of abnormal RCM features can be observed across the spectrum of keratinocytic neoplasias. The presence of an atypical honeycomb or a disarranged pattern of the spinous-granular layer, round nucleated cells at the spinous-granular layer, and round blood vessels traversing through the dermal papilla are the key RCM features of SCC.