Imagine that you’re a doctor treating a patient for back pain.

Imagine telling that patient that the cause  of his back pain is a tumor.

Imagine performing surgery on the patient’s back to remove the tumor.

Imagine opening up the patient’s back, and seeing . . . . tiny human feet and hands.

Yup.  A 35 year old truck driver in Russia was experiencing chronic back pain.  The cause of the back pain turned out to be a fully developed (but obviously dead) "parasitic twin" that he never knew he had.  Full story here.