This clinical trial is focused on studying a rare condition known as lingual microcystic lymphatic malformations (LMLMs). These are unusual vascular malformations that appear as clusters of cysts filled with lymph fluid or blood. They can cause significant issues, even if the lesions are small, such as oozing, bleeding, infections, and difficulties with speech, chewing, or breathing. Pain and cosmetic concerns are also common. The treatment being tested in this study is a solution called sirolimus, which is applied topically, meaning it is put directly on the affected area.

The purpose of the study is to evaluate how effective and safe the 1 mg/mL sirolimus solution is when applied once daily to the front part of the tongue affected by LMLMs in both children and adults. Participants will be observed over a period of 24 weeks, with assessments at various intervals: 4, 8, 12, 16, 20, and 24 weeks. During the study, the effects of the sirolimus solution will be compared to usual care, which involves no treatment. The study aims to see if there is an improvement in the condition of the LMLMs and to monitor any side effects that may occur.

Throughout the study, participants will have their condition evaluated by experts using photographs and will also provide their own assessments of symptoms like oozing, bleeding, and discomfort. The study will also look at the overall quality of life and any changes in the size of the lesions. Safety is a key focus, with regular checks for any adverse effects and monitoring of sirolimus levels in the blood. This trial seeks to provide valuable information on whether topical sirolimus can be a beneficial treatment for those with LMLMs.