In vivo reflectance confocal microscopy of shave biopsy wounds: feasibility of intraoperative mapping of cancer margins.

BACKGROUND: Reflectance confocal microscopy (RCM) images skin at cellular resolution and has shown utility for the diagnosis of nonmelanoma skin cancer in vivo. Topical application of aluminium chloride (AlCl(3)) enhances contrast in RCM images by brightening nuclei. OBJECTIVES: To investigate feasibility of RCM imaging of shave biopsy wounds using AlCl(3) as a contrast agent. METHODS: AlCl(3) staining was optimized, in terms of concentration vs. immersion time, on excised tissue ex vivo. RCM imaging protocol was tested in patients undergoing shave biopsies. The RCM images were retrospectively analysed and compared with the corresponding histopathology. RESULTS: For 35% AlCl(3) , routinely used for haemostasis in clinic, minimum immersion time was determined to be 1 min. We identified three consistent patterns of margins on RCM mosaic images by varying depth: epidermal margins, peripheral dermal margins, and deep dermal margins. Tumour islands of basal cell carcinoma were identified at peripheral or deep dermal margins, correlating on histopathology with aggregates of neoplastic basaloid cells. Atypical cobblestone or honeycomb patterns were identified at the epidermal margins in squamous cell carcinomas, correlating with a proliferation of atypical keratinocytes extending to biopsy margins. CONCLUSIONS: RCM imaging of shave biopsy wounds is feasible and demonstrates the future possibility of intraoperative mapping in surgical wounds.

Dermoscopic patterns and subclinical melanocytic nests in normal-appearing skin.

BACKGROUND: Dermoscopic patterns of normal-appearing skin have received little scrutiny. We have recently completed an analysis of dermoscopic patterns of naevi in children. OBJECTIVES: To describe dermoscopic patterns in the normal-appearing skin surrounding naevi and to explore histological features of patterned background skin. METHODS: Dermoscopic images of back naevi were obtained from a population-based sample of fifth grade students. The dermoscopic pattern of the background skin around the naevi was analysed. We examined histopathological features of background skin patterns in a convenience sample of seven specimens from six adult patients. RESULTS: We observed a dermoscopic pattern in the background of normal-appearing skin in 41% of 1192 dermoscopic images from the backs of the 443 children. The background skin pattern was less frequent in individuals with a fair skin (P < 0.001). A globular pattern was observed in 201 images (17%) and a reticular pattern was seen in 287 images (24%), of which 112 images also showed globules. Inter-rater reliability between the two observers for a random sample of 100 images was excellent (kappa = 0.77). In four specimens with a globular background pattern, microscopic melanocytic nests were observed in the normal-appearing skin. No subclinical naevus nests were observed in three reticular pattern specimens. CONCLUSIONS: Dermoscopically recognized patterns are commonly present in clinically normal skin of children. Microscopic melanocytic nests may be observed in normal-appearing skin with a globular skin pattern.

Dermoscopic patterns of naevi in fifth grade children of the Framingham school system.

BACKGROUND: Childhood is a critical period for naevogenesis. OBJECTIVE: To describe the prevalence of dermoscopic patterns of naevi using cross-sectional data from a population-based cohort of children. METHODS: We obtained overview digital photography of the back of fifth graders (age 10-11 years) from all 10 schools in Framingham, MA, U.S.A. From each participant, dermoscopic images of up to four naevi were obtained, including the largest and one randomly selected naevus on the upper back and a corresponding pair from the lower back. RESULTS: The study included 443 children, 61% boys, with 1181 back naevi analysed. Globular pattern was seen in 37% of naevi, reticular pattern in 13%, homogeneous pattern in 44% and complex (reticular-globular) dermoscopic pattern in 5%. Globular naevi were significantly more frequent and larger on the upper than the lower back. There was a significant hierarchic trend in naevus diameter by dermoscopic pattern: complex naevi (4.3 mm)>globular (3.3 mm)>reticular (3.0 mm)>homogeneous (2.8 mm). Reticular naevi were more prevalent in children with darker pigment phenotype (P<0.0001). There was a decrease in the size of naevi in children with darker pigmentation (P<0.0001). CONCLUSIONS: An interrelationship was observed in childhood between dermoscopic pattern, naevus size, anatomical location on the back and pigment phenotype.