Fig. 3

Development of chronic lymphedema in a male with congenital KHE with KMP. a A 2-day-old male infant was referred due to a congenital vascular mass on his left upper extremity. The mass was indurate and purpuric. His platelet count was 9 × 10 [9]/L. b Coronal T2-weighted MRI revealed a hyperintense left upper extremity mass with ill-defined margins and reticular stranding in multiple tissue planes. Photographs at 6 (c), 12 (d) and 18 (e) months after sirolimus treatment showed a decrease in extremity swelling. f At 2 years of age, lymphoscintigraphy demonstrated the absence of draining tracts and axillary node drainage 2 h after injection, with backflow in cutaneous collateral lymphatics. A diagnosis of lymphedema was made. The sirolimus therapy was tapered and discontinued. g Three months after the cessation of sirolimus; the photograph showed a rebound of the extremity swelling, requiring sirolimus reintroduction. h At 3.5 years of age, the patient still received a low dose of sirolimus (trough level, 3–5 ng/ml)