title: An umbilical nodule with cyclical changes.
authors.affiliation: Department of Dermatology and Allergology, Hochgebirgsklinik, Davos, Switzerland. matthias.moehrenschlager@hgk.ch
authors.forename: Matthias
authors.initials: M
authors.lastname: Möhrenschlager
authors.forename: Helmut P
authors.initials: HP
authors.lastname: Arbogast
authors.forename: Verena
authors.initials: V
authors.lastname: Henkel
mesh_terms: D004715:Endometriosis / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D014472:Umbilicus