Author Affiliations: Departments of Plastic and Reconstructive Surgery (Drs Mizutani and Ochiai) and Pathology (Dr Maeshima), National Hospital Organization Tokyo Medical Center, Tokyo, Japan; and Department of Plastic and Reconstructive Surgery, Keio University School of Medicine, Tokyo (Dr Sakamoto).
Umbilical endometriosis, also called Villar nodule, is an extremely rare type of endometriosis, with an incidence of 0.5% to 0.1% among women with extragonadal or external endometriosis.1 The urachus, a vestigial structure arising from the anterior bladder wall, is progressively destroyed with advancing age, but destruction does not occur in approximately 1 in 5000 individuals.2 This report describes a case of umbilical endometriosis that developed in the absence of previous abdominal or uterine surgery.
Mizutani T, Sakamoto Y, Ochiai H, Maeshima A. Umbilical Endometriosis With Urachal Remnant. Arch Dermatol. 2012;148(11):1331-1332. doi:10.1001/archdermatol.2012.1983