A cystic hygroma is a malformation of the lymphatic system that results in a cyst filled with lymphatic fluid. It is most commonly a congenital abnormality and is typically located in the posterior triangle of the neck on the left side.
It may be seen on antenatal scans, picked up on routine baby checks or discovered later when noticed incidentally.
Cystic hygromas most commonly present in the neck or armpit. They:
- Can be very large
- Are soft
- Are non-tender
To transilluminate the cystic hygroma, hold a pen torch flat against the skin and watch as the whole thing lights up like a bulb.
Depending on the location and size, cystic hygromas can interfere with feeding, swallowing or breathing. It can become infected, in which case it will turn red, hot and tender. There can be haemorrhage into the cyst.
Treatment varies based on the size, location and complications. Watching and waiting can be appropriate as it is a benign condition. They do not resolve spontaneously, but can show some regression.
Aspiration (giving temporary improvement), surgical removal and sclerotherapy are treatment options.
Last updated January 2020