Development of metastatic endometrial endometrioid adenocarcinoma while on progestin therapy for endometrial hyperplasia

Currently, there are no good criteria for predicting which patients with complex atypical hyperplasia/grade 1 endometrioid adenocarcinoma will optimally respond to progestin therapy. There is some evidence that endometrial complex hyperplasia demonstrating loss of MLH1 protein by immunohistochemistry is strongly related to subsequent or concurrent endometrial cancer, especially tumors of higher grade and stage. In a woman with a biopsy diagnosis of endometrial hyperplasia, evaluation of MLH1 protein status by immunohistochemistry may provide useful information when medical management is being considered.