Lung cancer desmoplasia. Fluorescence light micrograph of a stromal desmoplastic reaction associated with lung cancer. Desmoplasia is the growth of fibrous or connective tissue, and may occur around a neoplasm (cancer), causing dense fibrosis. Here, the connective tissue associated with the tumour has thickened in a similar manner to scar formation. Cancer cells are shown in red, while cell nuclei are shown in cyan. The stroma/desmoplasia region is shown in green, while an active stroma-specific marker shows as purple.