Of these cases only about 70 have had been located in the pelvis or in retroperitoneal locations 3. It has been established that fewer than 150 of the cases were reported in the English language literature between 1983 and 2004 2.
Del total de casos mencionados, solo unos 70 de estos tienen una localización anatómica pélvica y/o retroperitoneal 3, y se estableció que menos de 150 de los casos han sido reportados en la literatura médica inglesa entre 1983 y 2004 2.