Clinicopathological Features of Carcinoma of the Lower Uterine Segment and Relationship with Lynch Syndrome

Abstract

Endometrial cancer arises from the uterine body and fundus in many cases, but can also originate from the lower region of the uterine body through the upper region of the cervix. Such tumors are referred to as carcinoma of the lower uterine segment （LUS） or isthmus, and account for 3–3.5% of all cases of endometrial cancer. This relatively low incidence has permitted performance of only small-scale studies, but recently it has been reported that carcinoma of the LUS is associated with Lynch syndrome. The frequency of Lynch syndrome in cases of general endometrial cancer is 1–2%. In contrast, the frequency in patients with carcinoma of the LUS is much higher, with up to 29% of cases diagnosable with Lynch syndrome and a high frequency of MSH2 mutation found in one study. This suggests that further investigation of the clinical and pathological characteristics of carcinoma of the LUS and the association with Lynch syndrome is required through performance of a large-scale survey.