Well Differentiated Endometrioid Adenocarcinoma of the Endometrium with "Adenoma Malignum-Like" Pattern of Invasion: Report of Two Cases and Review of Literature.

Unusual variants of endometrial endometrioid adenocarcinoma can be diagnostically challenging and pose difficulties to differentiate from their benign and malignant mimickers. Here we describe an entity that has been well documented in the literature, yet little is known about true outcome due to lack of studies with a large number of cases. Diffusely infiltrative or "adenoma-malignum-like" is an uncommon pattern of invasion in endometrioid endometrial adenocarcinoma which could be confused with adenomyosis. To the best of our knowledge only 58 cases (excluding these 2 cases) have been reported up to date in the English literature.