Fetal cystic and solid tumor of the atrioventricular node: Autopsy diagnosis at 12 weeks of gestational age

Primary cardiac tumors are uncommon clinical entities with an incidence of 0.0017% to 0.03% of all autopsies. Cystic tumor of the atrioventricular node (CTAVN) comprises of 2.7% of cardiac tumors causing sudden death associated with complete heart block. CTAVN is a congenital benign cystic and solid mass located in the triangle of Koch in atrioventricular nodal region of the heart. It has been described from infancy to adulthood, most often as an incidental finding at autopsy, but has been not yet described in fetuses. We report a case of late spontaneous abortion detected during the first ultrasound follow-up consultation at 12w+1d of gestation in a healthy 23-year-old pregnant woman, gravida 2 para 0 and one previous termination of pregnancy. Pathological study of abortion product was request. No abnormalities were detected on gross examination, but microscopically, characteristics features of cardiac cystic and solid tumor of the atrioventricular node were identified. We present the first case described in literature of a congenital benign CTAVN in a non-macerate, normal, female fetus with an appropriate growth and development for 12w+1d of gestational age. There are many reasons for performing a fetal post-mortem autopsy foremost of which is identifying an accurate cause of death.