A case of diprosopus: a rare form of twinning radiology-pathology correlation

Objectives: Diprosopus is a rare subtype of conjoined twinning, with approximately 30 reported cases in English literature. Due to the rarity of conjoined twins, the mechanism leading to this developmental anomaly is not yet understood. Case presentation: We present a case of diprosopus with multimodality imaging (prenatal and postnatal), and with pathological correlations. Developmental anomalies include partial duplication of frontal lobes, formation of a midline "third" frontal lobe, as well as orofacial and cardiac anomalies. The constellation of anomalies coincide with development during embryonic days 23-26, where the anterior prosencephalon, prechordal plate/oropharyngeal membrane, and cardiogenic plate are in very close proximity to each other. Conclusions: This case offers an opportunity to better appreciate the radiologic and pathologic manifestations of diprosopus, and adds to the current body of evidence.