Morphometric characteristics of basal cell carcinoma peritumoral stroma varies among basal cell carcinoma subtypes

Ninety eight digitized basal cell carcinoma histology slides were categorized as infiltrative, nodular, or superficial subtypes, and were analysed using a combination of manual and computer-assisted approaches. The morphometric characteristics of the tumour nests and their associated peritumoral stroma were quantified, and the presence of a marked immune reaction or elastosis was noted.The tumour to stroma ratio was different among each tumour subtype. Elastosis was identified in a greater proportion of the infiltrative tumours.Quantitative differences exist between the peritumoral stroma of basal cell carcinoma subtypes. Future work exploring the relation between these morphometric differences and biochemical variations in peritumoral stroma may further our understanding of the biology of carcinoma development.Not applicable.Carcinomas (cancers derived from epithelial cells) are accompanied by a specialized peritumoral stroma which plays an important but poorly understood role in the growth and metastasis of the tumour [1-4]. The peritumoral stroma is composed largely of activated fibroblasts, inflammatory cells and vasculature and engages in a complex crosstalk with the developing tumour. This interplay appears to be mediated largely by soluble paracrine factors [1-17].Modifications to the peritumoral stroma include alterations in the secretion of extracellular matrix proteins and growth factors by fibroblasts. Particularly important are the stromally expressed matrix metalloproteinases (MMPs), which may have wide-ranging effects on tumor growth, angiogenesis and metastasis [17]. A number of other soluble fibroblast-derived factors have been shown to induce carcinoma initiation and progression with Wnt-1, HGF and TGF-β playing particularly prominent roles [18]. Gene expression profiling of both stroma and tumor in an inducible human neoplasia model showed that during tumour growth epidermal tissue first showed increased expression of genes mediating cellular biosy