carcinoma characterized by bands or cylinders of hyalinized or mucinous stroma separating or surrounded by nests or cords of small
epithelial cells. When the cylinders occur within masses of
epithelial cells, they give the tissue a perforated, sievelike, or cribriform appearance. Such tumors occur in the mammary glands, the mucous glands of the upper and lower respiratory tract, and the
salivary glands. They are malignant but slow-growing, and tend to spread locally via the nerves. (Dorland, 27th ed)