A case of microcystic lymphatic malformation successfully treated with topical sirolimus.

Microcystic lymphatic malformation (MLM), also known as "lymphangioma circumscriptum," is a lymphatic malformation which may involve the skin and subcutaneous tissues. Progressive growth of lesions may cause pressure to the surrounding organs. Lesions frequently reoccur after treatment with surgery, sclerotherapy, radiotherapy, and laser therapy. In the last decades, oral sirolimus has been successfully used in lymphatic malformations. Since systemic treatment with sirolimus is associated with various side effects, topical form of the drug has been used with satisfying results, especially for the angiofibromas. Promisingly, few case studies indicate topical sirolimus as a potential treatment for the lymphatic malformations. Here, we report an 8-year-old girl with MLM on left trunk whose lesions recurred after the surgery that has been performed at 1 year of age. We administered twice daily topical sirolimus at 0.75 mg/ml concentration. After 2 weeks, a local irritation occurred and the dose was decreased to once daily. The treatment was stopped at the end of 3 months as the lesions were almost cleared and the patient did not want to continue to therapy. There were no new lesions after 8 months of follow up.