You can have high levels of testosterone
without all the signs of PCOS and
that can cause hirsutism. High testosterone
in women is often labelled PCOS for reasons I don't fully understand even if one has only one symptom (eg hirsutism) and no sign of polycystic ovaries. Also, menstrual irregularities, not just amenorrhea, can be related to PCOS/high testosterone.
My very thin daughter had treatment resistant acne and was found to have high testosterone, but no other signs of PCOS.