Trial Information

In Vivo Confocal Scanning Laser Microscopy of Benign Globular, Homogeneous and Reticular Nevi; Comparison With Dermoscopy and Histopathology

This study included 29 patients, which were recruited consecutively at our pigmented skin
lesion clinic at the Department of Dermatology, University Hospital Graz, Austria. A total
of 30 benign nevi were imaged; 10 dermoscopically reticular, 10 globular and 10 homogeneous
nevi were selected. Lesions were selected for the presence of a uniform dermoscopic pattern.
A biopsy of one nevus of each group was performed due to cosmetic purposes on patient’s
request.

Each nevus was imaged with a confocal scanning laser microscope (Vivascope 1000, Lucid Inc,
Henrietta, NY). Technical details of the confocal scanning microscope have been described
elsewhere. The adaptor ring of the laser microscope was applied to the skin and centered on
the lesion. A standardized evaluation was performed; CSLM imaging of the lesion centre was
started stepwise (approximately 20µm per step) beginning from stratum corneum to the
papillary dermis with a field of view of 475 x 350 µm for a single image (´stack´ image).
Each image corresponds to a horizontal section at a selected depth with a resolution of
640x480 pixels and 255 colors (grey scale). An automated stepper was used to obtain a grid
of 16 contiguous horizontal images of the basal layer, constructing a montage image with a
1.9x1.4mm field of view (´block´ image). Since selected nevi showed a uniform pigmentation
pattern throughout the whole lesion, a correlation between clinical, dermoscopic and
confocal images could be guaranteed. One nevus of each group was consecutively biopsied and
assessed with conventional histopathologic examination after sectioning and staining with
hematoxylin and eosin (H&E).

Cytomorphologic and architectural features of each nevus were evaluated during assessment of
confocal images and distinct characteristics for each group of nevi were determined and
correlated with dermoscopy and, if available, with histopathology. The diagnostic
applicability of CSLM in the differentiation between reticular, globular and homogeneous
nevi based on these features was assessed by two independent observers.