Medically reviewed by Sukaina Hasnie, MD Key Takeaways A lump behind the ear can be caused by swollen lymph nodes, which are common and usually harmless.Most lumps behind the ear are benign and can be ...

A pineal cyst is a benign fluid-filled sac that occurs in the brain’s pineal gland. Although they usually don’t cause symptoms, some people may experience vague symptoms, like a headache. Pineal cysts ...