Teratomas are tumors made up of tissues, such as hair, muscle, and bone. They occur most often in the ovaries in women, and the testicles in men. They may be benign or malignant.
Symptoms vary depending on the location. A painful lump or swelling may be apparent. Some babies have a mass that can be seen on an ultrasound before birth.
Treatment often involves surgery. In rare cases when a teratoma is malignant, chemotherapy or radiation may be needed.