Awasome Tumor Hair And Teeth References. Teratomas are most common in the tailbone, ovaries,. Dermoid cysts often form on your head and neck but may also be in your ovaries, on your spine or elsewhere in your body.

They most commonly affect the ovaries, testicles, and tailbone. Most teratomas are benign (noncancerous) but they can be malignant (cancerous). Although teratomas are found primarily in the gonads, they can develop anywhere in the body, especially in midline locations, such as the sacrum, coccyx, mediastinum, retroperitoneum, and central nervous system.