title: A case of polypoid endometriosis with malignant transformation.
abstract: Polypoid endometriosis is a benign, rare variant of endometriosis which forms multiple polypoid nodules in the female pelvis mimicking malignant tumors; however, it may rarely cause malignant transformation. We report magnetic resonance imaging findings of a case of polypoid endometriosis with malignant transformation. Multiple high-signal intensity polypoid nodules in the cul-de-sac surrounded by low-signal intensity rim-like fibrous adhesion protruding to the posterior wall of the uterine body were demonstrated on T2-weighted images. The polypoid nodules showed weak contrast enhancement compared with that of uterine myometrium on post-contrast T1-weighted images, and slight high signal intensity on diffusion-weighted images with relatively high mean apparent diffusion coefficient. Reported cases of polypoid endometriosis showed intense contrast enhancement similar to that of uterine myometrium, and weak contrast enhancement similar to that of endometrial carcinoma may be suggestive for malignant transformation of polypoid endometriosis.
authors.affiliation: Department of Radiology, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, 7708503, Japan. mayumi@tokushima-u.ac.jp.
authors.forename: Mayumi
authors.identifier: 0000-0001-8447-7620
authors.initials: M
authors.lastname: Takeuchi
authors.affiliation: Department of Radiology, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, 7708503, Japan.|Department of Radiological Technology, Tokushima Bunri University, 1314-1, Shido, Sanuki City, Kagawa, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsuzaki
authors.affiliation: Division of Pathology, Tokushima University Hospital, 2-50-1, Kuramoto-cho, Tokushima, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Bando
authors.affiliation: Department of Obstetrics and Gynecology, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: Division of Pathology, Tokushima University Hospital, 2-50-1, Kuramoto-cho, Tokushima, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Yoneda
authors.affiliation: Department of Radiology, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, 7708503, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
mesh_terms: D016889:Endometrial Neoplasms; D004715:Endometriosis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging
keywords: Endometrioid carcinoma; Magnetic resonance imaging (MRI); Malignant transformation; Polypoid endometriosis; Uterus