ENDOMETRİAL POLYPS

• Endometrial polyps are typically encountered in the reproductive and postmenopausal age groups;65% of patients are over the age of 40. Polyps are present in as many as 25% of endometrial biopsy specimens performed for abnormal uterina bleeding, although they are often an incidental finding. Sbouth 10%of polyps prolapse into the endocervix, often mimicking an endocervical polyp.
• Polyps are the most common endometrial lesion associated with tamoxifen therapy, being present in as many as one-third of these patients. Tamoxifen-related polyps tend to be larger, more commonly multiple, and are more likely to recur.
• Polyps most often arise in the fundus. In a study of 1100 polyps, Peterson and Novak found them to range from 0.3 to 12 cm (mean, 2.3 cm); 20% werw multiple. Polyps have a broad to narrow base, a usually smooth external surface, and an often cystic and/or fibrotic sectioned surface. Focal hemorrhage may be seen, particularly at their tips, due to torsion with subsequent infaretion.

Microscopic features

• The glandular and stromal morphology is highly variable and may differ from or reflect the appearance elsewhere in the endometrium.
• The glands are often inactiveand cystic, particularly after the menopause, but functional (proliferative or secretory), metaplastic, hyperplastic, or even carcinomatous glands may be present. The glands are often arranged parallel to the surface epithelium. We allow some gland crowding in polyps, including cellular stratification and mitotic activity, withouth rendering a diagnosis of hyperplasia.
• A mixture of endometrial and endocervical-type glands may be ancountered in polyps arising near the internal os.
• Glandular features more commonly present in tamoxifen-related than in tamoxifen-unrelated polyps includeglands polarized along the long axis of the polyps, focal stromal hypercellularity, staghorn-shaped glands, small glands, and metaplastic glands.
• Polyps may contain a distinctive proliferation of fibrous-cored papillae and metaplastic epithelium, as described by Lehman and Hart (see below).
• Hyperplasia and adenocarcinoma have been found in as many as 11-30% and 0.5-3% of polyps, respectively, in the general population. Carcinoma has been found in 3.0- 10.7% of polyps in tamoxifen-treated women.
• İn women with complex hyperplasia within polyps, da Costa and Mittal found hyperplasia or adenocarcinoma of nonpolypoid endometrium in the hysterectomy specimen in 72% and 31% of cases, respectvely. Some of the carcinomas were myoinvasive.
• Carcinomas found in polyps (tamoxifen related and tamoxifen unrelated) may be confined to the polyp or be part of a multifocal endometrial neoplasia. They are usually endometrioid or serıous, or rarely other cell types. The serous carcinomas, in particular, are often microscopic and /or noninvasive and can be overlooked. Tmoxifen-related polyps may also harbor metastatic lobular breast carcinoma.

• The stroma of endometrial polyps may be fibrotic and sparsely cellular, especially in tamoxifen-related polyps. İn other cases, it resembles normal or hypercellular endometrial stroma; in these polyps, mitotic figures in the stromal cells may be present.
• Blood vessels, which are often thick-walled and/or hyalinized, are more numerous in polyps than in the normal endometrium, and are sometimes a helpful clue to the diagnosis.
• Atypical stromal cells, which may be multinucleated, are a rare focal, multifocal, or diffuse finding within a polyp. Their nuclei can be moderately to severely atypical and hyperchromatic, often with a smudged appearnce. Mitotic figures are usually absent.
• Other uncommon stromal findings include foci of smooth muscle and decidua, the latter usually reflecting exogenous progestin use latter usually reflecting exogenous progestin use or pregnancy.
• Vascular thrombosis and hemorrhagic necrosis can occur within the polyp, and hemorrhagic necrosis can occur within the polyp, and may result in reactive atypia of the epithelium or stroma of the polyp.