title: A painful umbilical nodule in a 24-year-old woman. Umbilical endometriosis (Villar nodule).
authors.affiliation: Dipartimento di Fisiopatologia medico-chirurgica e dei trapianti, Università degli Studi di Milano - Fondazione IRCCS Cá Granda Ospedale Maggiore Policlinico, Milano, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Nazzaro
authors.forename: Antonella
authors.initials: A
authors.lastname: Coggi
authors.forename: Raffaele
authors.initials: R
authors.lastname: Gianotti
mesh_terms: D001706:Biopsy; D004715:Endometriosis / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D010146:Pain / Q000473:pathology*; D014472:Umbilicus / Q000473:pathology* / Q000601:surgery; D055815:Young Adult