Case of the haunted scrotum

In October 1996, the Journal of the Royal Society of Medicine published the following missive and photo contributed by JR Harding, a consultant radiologist at the Royal Gwent Hospital:

 Blog Files 2010 01 Hauntedscrotum
A 45-year-old man was referred for investigation of an undescended right testis by computed tomography (CT). An ultrasound scan showed a normal testis and epididymis on the left side. The right testis was not visualized in the scrotal sac or in the right inguinal region. On CT scanning of the abdomen and pelvis, the right testis was not identified but the left side of the scrotum seemed to be occupied by a screaming ghostlike apparition (Figure 1). By chance, the distribution of normal anatomical structures within the left side of the scrotum had combined to produce this image. What of the undescended right testis? None was found. If you were a right testis, would you want to share the scrotum with that?

"The case of the haunted scrotum" (via Mind Hacks, thanks Vann Hall)