Polypoid endometriosis: An uncommon and distinctive variant of endometriosis

A case of polypoid endometriosis is reported. The mass was located on the right rear side of the uterus, and showed isointensity to myometrium on T1-weighted images, hyperintensity on T2-weighted images, and gradual and inhomogeneous enhancement on dynamic contrast study corresponding to dilated endometrial glands. Punctuate regions within the mass showed hyperintensity on T1-weighted images corresponding to hemorrhage. A hypointense rim on T2-weighted images was identified. The imaging findings indicated a malignant tumor, but surgical specimen showed polypoid endometriosis. We should recognize this rare disease to avoid excessive resection.