We read with considerable interest the article by Nezhat and Mahmoud [ 1 Nezhat F.R. Mahmoud M.S. Allen-Masters peritoneal defect: a potential pathway to deep infiltrating rectovaginal endometriosis?. J Minim Invasive Gynecol. 2014; 21: 321-322 Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar ]. In response, we believe that neither the images nor the clinical presentation represent traumatic laceration of uterine supports, as reported by Allen and Masters in 1955 [ 2 Allen W.M. Masters W.H. Traumatic laceration of uterine support: the clinical syndrome and operative treatment. Am J Obstet Gynecol. 1955; 70: 500-513 Abstract Full Text PDF PubMed Scopus (73) Google Scholar ]. Rather, the lesion shown in Fig. 1 is a fenestrated cryptic recess in the posterior cul-de-sac, medial to the right uterosacral ligament. It is not an Allen-Masters fascial defect; it is not even in the correct location for an Allen-Masters fascial defect. Allen Masters Peritoneal Defect: A Potential Pathway to Deep Infiltrating Rectovaginal Endometriosis?Journal of Minimally Invasive GynecologyVol. 21Issue 3PreviewDeep infiltrative endometriosis of the rectovaginal septum can be one of the most severe forms of endometriosis. It is characterized by spherically shaped lesions situated deep in the rectovaginal septum and often only visible as a small typical lesion at laparoscopy or not visible at all. This lesion is often more palpable than visible and can be tender during pelvic examination, especially if the patient is examined at the time of menstruation, and can cause severe dyspareunia, back pain, and sometimes bowel symptoms. Full-Text PDF