HPI: Patient is an 11-month old infant who was noted at birth to have difuse capillary malformations over most of her trunk and limbs(Figs.1,2) as well as macrodactyly of several fingers and toes(Fig.3). These findings were accompanied with a vascular mass on the right buttock, a microcystic lymphatic malformation on her neck (identified with ultrasound), and an ostium secundum atrial septal defect. Magnetic resonance imaging performed at 5 months of age also identified a small slow-flow vascular malformation in the subcutaneous tissues of the right flank. Skeletal survey was consistent with macrodactyly of fingers and toes and MRI of the brain was within normal limits, including normal structural anatomy and normal flow voids in the carotid and basilar arteries. Due to recurrent episodes of bleeding, swelling, and pain, the vascular mass on the right buttock was excised. Despite these findings, the patient continued to meet appropriate developmental milestones and remained otherwise healthy.
Past medical history: Born full term to a P3G3 mother with gestational DM via repeat c-section
Social Hx: Lives with parents in St. Louis
Family Hx: No family members with similar findings; both parents are in good health; port-wine stain in father’s second cousin
Physical examination: diffuse confluent, reticulated, blanchable pink-red patches involving the trunk, extremities, and buttocks; elongation and widening of several digits on the hands and feet; and large head circumference, which increased from the 86th to 96th percentile between 5 and 11 months of age.
Laboratory results: Genetic testing on a skin sample from a capillary malformation was positive for an activating mutation in the phosphatidylinositol-3-kinase/AKT/mTOR (PIK3CA) pathway, while testing of peripheral blood was negative, indicating a mosaic state. The specific somatic mutation in the skin sample was identified in the p.E453K protein.