Cystic tumors and cysts are fluid-filled sacs that can arise in any organ or soft tissue. Most are benign and asymptomatic, but enlargement, infection, or malignant change may produce noticeable signs: Painless lump or swellingA smooth, round, compressible mass under the skin or within an organ; usually mobile and grows slowly. Local pressure or achingDull pain develops when the cyst compresses nerves or adjacent structures, especially if it reaches >3–4 cm. Sudden sharp painRapid enlargement, hemorrhage into the cyst, or rupture causes acute localized pain sometimes accompanied by bruising. Change in organ functionOvarian cysts may lead to menstrual irregularity; pancreatic... Learn more