Final answer:
Cystic hygromas typically develop in the neck or axilla and are associated with the lymphatic system, frequently occurring in subcutaneous tissue.
Step-by-step explanation:
Most cystic hygromas, which are fluid-filled sacs resulting from blockages in the lymphatic system, are commonly located in the neck or axilla (armpit area). These cysts may develop in any organ, but they are often found in subcutaneous tissue. They can also be present in other areas such as the brain and eyes, but cystic hygromas are most notably associated with the neck region of the body, particularly in children.