What is tubular adenoma of rectum?

Adenoma is a benign tumor of glandular epithelial tissue, with slow growth, no pain and other symptoms, small size, diameter less than 2cm, clear boundary and mobility. The pathological changes were observed by naked eyes: there was a complete capsule and the surface was smooth. The profile is brownish yellow, and there may be cysts of different sizes containing mucus. Microscopic observation: essence: the tumor is composed of columnar or cubic epithelium, arranged in double layers, and anastomosed with each other into irregular tubular or narrow trabecular shape. The nucleus is large, oval, uniform in size and eosinophilic in cytoplasm. There are no myoepithelial cells in the lumen or trabecular periphery. The lumen contains PAS positive secretion. Interstitial: loose, with a large number of capillaries and venules. There is a basement membrane separation between parenchyma and stroma. More common in the intestine, breast, thyroid, ovary and other places. Most adenomas in mucosa are polypoid, while adenomas in glandular organs are nodular and often enveloped, with a clear boundary with surrounding normal tissues. The gland structure of adenoma is similar to that of the corresponding normal tissue, and it often has a certain secretory function. According to the composition or morphological characteristics of adenoma, it can be divided into tubular adenoma, villous adenoma, cystadenoma, fibroadenoma and pleomorphic adenoma. (1) Tubular adenoma and villous adenoma: more common in colon and rectal mucosa. Polypoid, so it is often called adenomatous polyp. Sometimes both components are called tubular villous adenoma. Adenomas can be pedicled (connected to the mucosa, but they can also be relatively flat. The malignant rate of villous adenoma is high. (2) Cystic adenoma: It is the result of the accumulation of glandular secretions of adenoma, and the glandular cavities gradually expand and merge with each other. Cystic cavities of different sizes can be seen with the naked eye. It often occurs in ovaries and other parts.