Endometrioid adenocarcinoma, NOS
Endometrioid adenocarcinoma of the uterine corpus is a primary endometrial adenocarcinoma characterized by the presence of malignant glandular epithelial cells resembling endometrial cells. The great majority of patients present with abnormal uterine bleeding. The uterus is frequently enlarged. The tumour generally appears as a single dominant mass. It may extend into the underlying myometrium; advanced cases may penetrate the serosa or extend into the cervix. Highly characteristic histological features of endometrioid adenocarcinoma are glandular/villoglandular structures lined by columnar cells. In higher grade tumours, the fraction of glandular cells decreases and is replaced by solid nests and sheets of cells.
In addition to glandular cells, a variety of other differentiated epithelial cell types may be found in endometrial proliferations, including squamous/morular, mucinous, ciliated, cleared or eosinophilic cells; when these cell types are prominent in a tumour, it is termed a "special variant" carcinoma and subclassified into:
- variant with squamous differentiation
- villloglandular variant
- secretory variant
- ciliated cell variant
Endometrioid adenocarcinoma is the most common type of endometrial carcinomas. Most cases arise in postmenopausal women. The tumour is estrogen-dependent; driving force is unopposed estrogenic stimulation. Patients are frequently obese, diabetic, nulliparous, hypertensive, or have a late menopause. Most tumours are low-grade and have a favourable prognosis
Tavassoli FA, Devilee P (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Breast and Female Genital Organs.
IARC Press: Lyon 2003