What is a large mucus retention cyst?

A large mucus retention cyst is a fluid-filled sac that forms in a gland or tissue, often due to the obstruction of a duct that normally allows mucus to drain. These cysts can occur in various locations, such as the sinuses, salivary glands, or lungs, and may become asymptomatic or cause discomfort, swelling, or infection if they grow large. Treatment may involve monitoring, drainage, or surgical removal, depending on their size and symptoms.