Superficial Basal Cell Carcinoma

01Short fine telangiectasias are the dominant vascular pattern of superficial BCC. They are short, linear, with few or no branches, and reflect telangiectatic vessels in the papillary dermis. Reiter's pooled analysis of 1590 superficial BCCs reports prevalence 60 percent, compared with 17 percent in nodular BCC. Importantly, these vessels are not arborizing: branching, large-stem, in-focus vessels point to nodular or infiltrative subtypes.

02Multiple small erosions are highly characteristic of superficial BCC, present in 43 percent of cases and reduced to roughly 10 percent in nodular and infiltrative variants. They appear as small brown-red to brown-yellow crusts representing thin crusts overlying superficial epidermal loss. Lallas' multivariate analysis showed they make sBCC roughly 7.8-fold more likely.

03Shiny white-red structureless areas form the background of most superficial BCCs, present in 79 percent of cases. The translucent, opaque-to-red appearance reflects diffuse dermal fibrosis or fibrotic tumor stroma. Combined with leaf-like or spoke-wheel structures, this background is one of the only dermoscopic patterns that is relatively specific for the superficial subtype.

04Pigmented features when present in superficial BCC reflect melanin at the dermoepidermal junction or in small basaloid nests. Maple leaf-like areas (translucent brown to grey-blue peripheral bulbous extensions, prevalence 25 percent), spoke-wheel areas (radial brown-tan projections meeting at a darker central axis, 10 percent), and concentric structures (small irregular pigmented globules with darker central area, 14 percent) are all far more frequent in superficial than nonsuperficial BCC. These structures correlate to multifocal pigmented tumor nests connected to the epidermis on histology.

05Reflectance confocal microscopy of superficial BCC shows cords of basaloid cells connected to the epidermis, often with peripheral palisading and a thin layer of clefting. In Longo's 2014 series, cords connected to the epidermis were present in 66 percent of sBCCs and gave a 25-fold higher odds of superficial diagnosis. Streaming of the epidermis (focally elongated and distorted keratinocytes) appeared in 50 percent of sBCCs but is less specific. Collagen surrounding the cords (73 percent) supports the diagnosis but is also present in other subtypes.

06Treatment of low-risk superficial BCC offers multiple nonsurgical options. Imiquimod 5 percent cream applied 5 days per week for 6 weeks gives 78 to 80 percent clearance at 5 years (Geisse 2004; Quirk 2010). Topical 5-fluorouracil 5 percent cream gives 68 percent 3-year clearance, slightly inferior to imiquimod (Roozeboom 2016). Methyl aminolevulinate or aminolevulinic acid PDT yields 86 percent complete clearance with better cosmesis than surgery (Wang 2015 meta-analysis). Standard excision with 4 mm margins remains the gold standard with 5-year recurrence under 5 percent.

07Differential diagnosis with Bowen disease is the most common pitfall. Both present as flat pink scaly plaques, but Bowen tends to show glomerular or coiled vessels arranged in clusters, yellow scale, and a sharp border without leaf-like areas. Superficial BCC shows short fine telangiectasias, small erosions, leaf-like areas, and shiny white-red background. Papageorgiou (2018) found leaf-like areas, multiple blue-grey dots, and shiny white-red areas favor sBCC, while glomerular vessels and yellow scale favor Bowen disease.