Fig. 4.

Desmoplastic reaction of stroma and the basement membrane provide defence for the invasive and in situ carcinomas. (A) Ductal carcinoma in situ of breast is surrounded by lymphocytes. However, the basement membrane and collagenous fibres (stars) provide defence against the attack from lymphocytes. (B) In contrast with A, the microinvasive cancer cells of breast cancer are being attacked by inflammatory lymphocytes. (C) Undifferentiated adenocarcinoma of gallbladder demonstrated prominent desmoplastic reactions, with large amounts of collagenous fibres segregating the cancer cells. (D) In a well-differentiated adenocarcinoma of gallbladder, the stroma is close to normal. H.E. staining, bar = 100 μm.