Idiopathic postmenopausal decidual reaction of the endometrium. A clinicopathologic analysis of four cases

The clinical and pathological features of four cases of endometrial decidual reaction in postmenopausal women are described. There was no evident exogenous or endogenous source of progesterone excess in any of the patients. The pathological findings, including bulky polypoid tissue, necrosis, cellular pleomorphism, signet-ring-like decidual cells, and glandular atypia, raised the possibility of a malignant tumor in two of the cases. This report appears to be the first documenting an idiopathic decidual reaction in the endometrium of a postmenopausal patient.