Pathological changes of rectal tubular adenoma

Rectal tubular adenoma is a benign tumor of glandular epithelial tissue that grows slowly and has no pain or other symptoms. Generally speaking, endoscopic removal is the preferred method in clinical practice, and snare electrocautery resection can also be performed. This method causes relatively little damage, mild reaction, and good effect. How to identify rectal tubular adenomas? Let us now understand the pathological changes of rectal tubular adenoma.

Visual observation

It has a complete capsule and a smooth surface. The cross section is brown-yellow and may contain cysts of varying sizes containing mucus.

Microscope observation

Essence: The tumor is composed of columnar or cuboidal epithelium, arranged in double layers and anastomosing into irregular tubular or narrow trabecular shapes. The nuclei are large, oval, and uniform in size, and the cytoplasm is eosinophilic. There are no myoepithelial cells in the lumen or periphery of the trabeculae. The lumen contained PAS-positive secretions. Interstitium: loose, containing numerous capillaries and venules. The parenchyma and stroma are separated by a basement membrane.

Differential Diagnosis

Biological characteristics of basal cell adenoma of adenoid cystic carcinoma: the tumor grows slowly, is small in size, and has an intact capsule. Recurrence is rare after surgical resection. Histogenesis: The inner layer of cells is columnar, and the outer layer is basaloid cells, which are structurally similar to the excretory duct. It is speculated that its tissue origin may be the excretory duct epithelium.

Tubular adenomas, also known as "adenomatous polyps," are the most common type of colorectal adenoma. The villous component of tubular adenomas accounts for less than 20%. Adenomas are spherical, ellipsoidal or irregular in shape, with a smooth or lobed surface, pink in color, solid in texture, and often have pedicles of varying lengths and thicknesses attached to the intestinal mucosa. However, when the tumor is only a few millimeters in size, it may also be broad-based with no visible pedicle. The larger the tubular adenoma, the greater the chance of malignancy. When the adenoma is >2cm, the rate of canceration increases significantly. If the tumor cells show obvious pleomorphism and interstitial infiltration, it is called severe atypical hyperplasia or carcinoma.

Pathological changes of tubular adenoma: Macroscopic observation: complete capsule and smooth surface. The cross section is brown-yellow and may contain cysts of varying sizes containing mucus.

Microscopic observation of tubular adenoma: Essence: The tumor is composed of columnar or cuboidal epithelium, arranged in double layers, and anastomosing to form irregular tubular or narrow trabecular shapes. The nuclei are large, oval, and uniform in size, and the cytoplasm is eosinophilic. There are no myoepithelial cells in the lumen or periphery of the trabeculae. The lumen contained PAS-positive secretions. Interstitium: loose, containing numerous capillaries and venules. The parenchyma and stroma are separated by a basement membrane.

In the above article, we have learned in detail about the pathological changes of rectal tubular adenoma. If we are still unclear about our symptoms, it is recommended that we go to a regular hospital for examination and treatment as soon as possible.