Fig. 9
Retrorectal hamartoma (tailgut cyst) in a 46-year-old patient with gradually worsening dysmenorrhea and menometrorrhagia. a Axial fat-suppressed T1-W MR image shows a small-sized, well-defined and thin-walled T1-hyperintense cyst (thick arrow) isolated in the retrorectal space, along the right side of the anococcygeal raphe. b Sagittal and (c) axial T2-W MR images show a distinct T2-hypointense retrorectal cyst (thick arrows). Note the absence of posterior deep infiltrating endometriosis lesions but the presence of internal adenomyosis (thin arrows) consistent with the symptomatology