Differential Diagnosis for Cyst

The differential diagnosis for a cyst can be organized into the following categories:

• Single Most Likely Diagnosis
  • Simple cyst: This is the most common type of cyst and can occur in various parts of the body, such as the skin, ovaries, or kidneys. It is usually benign and filled with fluid.
• Other Likely Diagnoses
  • Epidermoid cyst: A type of cyst that forms when skin cells and keratin, a protein, accumulate in a sac under the skin.
  • Dermoid cyst: A type of cyst that contains skin, hair, and other tissue, often found on the face, neck, or ovaries.
  • Sebaceous cyst: A type of cyst that forms when the oil-producing glands in the skin become clogged, often found on the face, neck, or trunk.
• Do Not Miss Diagnoses
  • Malignant cyst (e.g., cystic carcinoma): Although rare, some cysts can be cancerous, and it is crucial to rule out malignancy, especially in older adults or those with a family history of cancer.
  • Infected cyst (e.g., abscess): An infected cyst can lead to serious complications, such as sepsis or tissue damage, if left untreated.
  • Cystic hygroma: A congenital condition characterized by a fluid-filled sac in the neck or head, which can cause respiratory or swallowing difficulties if left untreated.
• Rare Diagnoses
  • Bronchogenic cyst: A rare type of cyst that forms in the lungs or mediastinum, often congenital.
  • Gastrointestinal cyst: A rare type of cyst that forms in the digestive tract, often congenital or acquired due to trauma or inflammation.
  • Tarlov cyst: A rare type of cyst that forms in the spine, often asymptomatic but can cause neurological symptoms if it compresses nearby nerves.