I will say this, contrary to some people on this board, one does not necessarily need to be transsexual to be castrated or seek it out. For some people who identify as androgynes and transgenderists this is done to come closer or achieve thier personal gender identity. Also contrary to the belief of some transsexuals, this can be achieved fairly easily, though there are only a few doctors who will perform it.
There is classic trap of viewing things through just the TS, TV and CD dynamic, and it often ignores the entire group of people who fall between TV and TS. The person may be a transgenderist or androgyne.
Generally speaking this is how the categories break down for non-transsexuals in the transgender community:
TV/CD
Transgenderists
Androgynes
Transgenderists and Androgynes are often grouped into the group 2 (type 4) of the DSM IV regarding gender identity. But if you read any of the academic literature this "inbetween" group is starting to become better recognized and treatment methods are starting to be better understood.
In the past these inbetween categories were tough to diagnose and identify. In fact the problem is many therapist still view things through a strictly MtF or FtM and TS, TV and CD viewpoint. However many leading therapists and doctors in the field have began to recognize the "inbetween" category of people in which gender identity does not follow a binary and there is beginning to emerge a better understanding. These people where gender identity is a bit more complex, may seek castration out.
I would just like to notify you that they may be something else other than a transsexual, but they still may be transgendered.
Hopefully this answered the question.
Oh this is a really good link from the international journal of ->-bleeped-<-:
http://www.symposion.com/ijt/ijtvo06no02_04.htm#Some%20Key%20Definitions%20and%20Concepts:%20Clinical%20and%20CulturalThe article goes into great detail about the differences and it does suggest that there will be changes in the future with regards to treatment and diagnosis.
There is also this article from Temple university:
http://www.temple.edu/tempress/chapters_1100/1373_ch1.pdfAnd interesting little definition in the American Medical Student Association's transgender health initiative regarding Transgenderists:
3. Transgenderist
Transgenderist A transgenderist lives as the gender opposite their biological/anatomical sex, and may pursue various forms of hormonal and surgical intervention to adopt secondary sex characteristics of that gender, but does not seek gender reassignment surgery (vaginoplasty or phalloplasty - PowerPoint 1.8MB).
Bi-genderists are most often considered transgenderists who live only part time as the gender opposite their biological/anatomical sex. Hormonal and surgical intervention are only as appropriate, if at all, as the degree the bi-gender individual cares to present physical characteristics representative of the opposite gender.
Androgynists (or androgyne) may or may not be transgenderists, but we will include them here because, like the above, they usually chose to forgo gender reassignment surgery. As the name implies, androgynists adopt an appearance that is gender ambiguous. This is possible without hormonal or surgical intervention in most cases.
Living as a transgenderist can be extremely challenging, especially from a social perspective. In addition, transgenderists who forgo a gonadectomy inevitably find themselves on relatively high and extended doses of reproductive hormones obtained to counteract those produced in their natal sex. The health implications of long-term hormone use are addressed in LGBTPM's TGHI Hormones Info and History and Physical pages.
Link to page:
http://www.amsa.org/advocacy/lgbtpm/transterms.cfm