Prenatal diagnosis of sirenomelia with anencephaly and craniorachischisis totalis: A case report study

RATIONALE: Sirenomelia and anencephaly are well-defined congenital malformations that usually occur independently. PATIENT CONCERNS: We report a case of combined sirenomelia, anencephaly and complete rachischisis, diagnosed in the 16th week of gestation. DIAGNOSES: To our knowledge, this is the 7th case in the literature and the first that is diagnosed so early in pregnancy. INTERVENTIONS: The final diagnosis is confirmed with radiological examination after the termination of pregnancy. OUTCOMES: Prenatal diagnosis of sirenomelia is difficult due to the presence of kidney agenesis and severe oligohydramnios. LESSONS: The combination of sirenomelia and craniorachischisis totalis is extremely rare and prenatal ultrasound scan are a challenge, even for experts in the field.