Anesthetic blister induction to identify biopsy site prior to Mohs surgery.

BACKGROUND: Wrong-site surgery in dermatology often occurs due to difficulty finding the initial biopsy site prior to Mohs surgery. Patients frequently present for Mohs surgery weeks to months following the initial biopsy site. Visualization of the biopsy site may become difficult at presentation due to healing.
OBJECTIVE: To investigate the utility of anesthetic blister induction at a suspected biopsy site to identify the location prior to Mohs surgery. The proposed technique is visualization of a blister that is induced by local anesthetic administration at the proposed biopsy site. The addition of this technique among others such as curettage, dermoscopy, and UV fluorescence can prevent wrong-site surgery.
METHODS: A biopsy site of a squamous cell carcinoma on a patient was compared via photography for visibility at the time of initial biopsy, weeks following biopsy, and post-anesthetic blister induction.
RESULTS: The biopsy site was easier to locate with the assistance of a blister that formed as a result of local anesthetic administration.
CONCLUSION: Blister induction by local anesthetic administration can assist in accurately identifying healed or obscured biopsy sites.

Reflectance confocal microscopy criteria for squamous cell carcinomas and actinic keratoses.

OBJECTIVE: To identify criteria for the diagnosis of squamous cell carcinoma (SCC) and actinic keratosis (AK) by in vivo reflectance confocal microscopy (RCM). DESIGN: 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. SETTING: 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. RESULTS: 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%). CONCLUSIONS: 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.