Figure
1. Images of normal layers of the skin. (A) FF-OCT image showing
grayish epidermal lining (pink arrow), dermis (green asterisk), and
underlying subcutis (pink asterisk). (B) A stratified layer of the
epidermis (pink arrow) shows multiple round to oval dark nuclei
surrounded by bright (grayish) cytoplasm. The underlying dermis appears
grayish (green asterisk). (C) Adipocytes of the subcutis appear as dark
polygonal structures separated by thin white septa (pink asterisk).
(D-F) Corresponding histopathology section stained with Toluidine blue.
Magnifications: (A) = 5.2 mm x 5.2 mm; (B, C) = 300 x 150 mm; (D)= 10x;
(E, F) = 40x .
Hair follicles (Supplemental Figure 2) appeared as tubular to
round structures with a central dark hole lined by an inner grayish
epidermal layer and an outer bright fibrous layer. Sometimes a bright
hair shaft was identified in the center of these follicles making their
identification easy. Sebaceous glands (Supplemental Figure 2)appeared as round to oval
varied-sized darkish (hypo-reflective) structures composed of multiple
lobules separated by thin bright (hyper-reflective) fibrous septa. Due
to their round shape, these glands were difficult to distinguish from
nBCC; however, the presence of multiple small bright
punctate particles, which we
speculate to be the sebum particulates, aided in the distinction.
Eccrine glands (Supplemental Figure 2) appeared as tightly
packed clusters of small, round to oval grayish (hypo-reflective)
structures separated by thin bright septa. Within the gland’s lumen,
small punctate bright particles (similar to sebaceous glands) could be
seen. Eccrine ducts (Supplemental Figure 2) were seen within
the clusters of eccrine glands as small roundish structures with a
central dark (areflective lumen) and lined by grayish cells. The eccrine
unit (glands and ducts) could be identified as embedded within dark
(areflective) adipose tissue.
Smooth muscles (Supplemental Figure 3) could be identified as
bundles of grayish (hypo-reflective) structures with intervening bright
thin fibrous bands. Cigar-shaped
dark elongated nuclei were seen within the muscle fibers. The smooth
muscle bundles were seen lining the dark lumen of medium-sized blood
vessels and attached to a hair follicle (as arrector pili muscle).
2) Basal cell carcinoma: Classic features of BCC could be
identified on FF-OCT. BCC tumor nodules appeared as round to oval varied
size structures composed of clusters of grayish (hyporeflective)
pleomorphic cells with dark nuclei (Figures 2, 3) . These tumor
nuclei were seen arranged perpendicular at the periphery of the nodule
forming “palisading”. Clefting was identified as a dark (areflective
area) around tumor nodules.