Abstract
We report a case with dysgenesis of the carotid artery associated with congenital Horner syndrome. A 6-year-old boy, who had undergone surgical repair for pulmonary atresia, ventricular septal defect, and patent ductus arteriosus at 20 months of age, presented with miosis of the left eye, and anhidrosis of the left face, neck, and shoulder girdle. Since the anhidrosis was obvious in early childhood, he was suspected as having congenital Horner syndrome. Cranial and cervical CT showed unpredicted abnormalities of the left carotid arteries, including the absence of an internal carotid artery (ICA), and hypoplasia of the common carotid and external carotid arteries. The anterior and middle cerebral arterial flow was supplied through the communicating arteries. Congenital agenesis of the ICA was highly suspected, because the left carotid canal could not be discerned at all. The concurrence of agenesis of ICA with ipsilateral Homer syndrome is accounted for by simultaneous organogenesis of the carotid artery and cervical sympathetic nerve, both of which are derived from neural crest cells. Developmental anomalies of the cervical neural crest, though rare, should be included in the differential diagnosis of congenital Horner syndrome.
