26 year old, Yamini Karanam made headlines last week after surgery revealed that her brain tumour contained teeth, hair and bone. Although Karanam joked that it was her “evil twin sister”, in reality, the horrific growth was a particular type of tumour known as a teratoma (literally “monster tumour”).
Karanam’s tumour is not the first or even the most disturbing of these teratomas to have been found. The structures discovered within some ovarian teratomas often seem as if they have come straight out of a nightmare. In 2007, a head-like structure with one fully formed eye was found within a large ovarian cyst. Even more worthy of a sci-fi plot twist, a young Japanese woman was discovered to have a fetiform teratoma, something that resembled a foetus with a “head, trunk and extremities” as well as internal organs.
All tumours can be thought of as excessive amounts of cells growing where they don’t belong, but whilst the cells of your run-of-the-mill tumour tend to be determined by its location, teratomas are composed of cells derived from the three “germ” layers (layers which other tissues are derived from) present in the developing embryo. These cells are pluripotent, meaning they have the capability to become almost any cell type which is why it is possible for them to grow anything from teeth to organs.
It is still unclear just how these cells find themselves in the wrong place although it is thought that they may ‘escape’ from their original position during development, but still believe they are growing to form part of a whole tissue or organ.
Whilst this sometimes leads to the whole structures mentioned above, it can also have other extraordinary consequences. In 2010, American Kiera Echols began to experience severe headaches, hallucinations and developed encephalitis (inflammation of the brain) due to her teratoma. However, the teratoma, too small to be seen on a CT scan, was not located in her brain but on her ovary. It was revealed that the tumour consisted of brain cells, so when Echols’ immune system was triggered to produce antibodies against it, they attacked not only the growth but her brain too. Fortunately, she made a full recovery but it just serves to illustrate the unusual damage these tumours can do.
(For the sake of the squeamish I have not included images, but if you really want a scare just look on Google images.)