Currarino syndrome (CS) is an autosomal dominant disorder of embryonic development characterized by the triad of anorectal abnormalities, partial sacral agenesis, and presacral mass. Mutations of the HLXB9 gene have been identified in most CS cases, but a precise genotype–phenotype correlation has not been described so far. We report the clinical case of a 44-year-old Caucasian woman with malignant neuroendocrine transformation of a pre-sacrococcygeal mass combined with bicornuate uterus, dermoid cyst of the ovaries, and chronic constipation. After the patient died, a sacrococcygeal malformation and anterior meningocele were diagnosed in her 22-year-old son. CS diagnosis was then retrospectively confirmed by molecular analysis of normal and pathological tissue specimens of the mother, with identification of a HLXB9 mutation (c.727C>T; p.R243W). CS should be considered, and genetic counseling recommended, to all patients with presacral masses. Since malignant neuroendocrine transformation of presacral mass in CS is a possible complication, even thought rare, close follow up in these patients is advisable. © 2011 Wiley Periodicals, Inc.