Mtwesi says she is a doctor only within the confines of the hospital and during consultations with patients - but outside her profession, she's "free to be".
"After the tweet I put out, some random person anonymously sent me details of the woman - where she works and even told me she works night shift today. I then called to confirm these details with her manager and my lawyers will serve her with legal papers."
Mtwesi says a Johannesburg law firm offered to represent her pro bono (at no cost), following the tweets in which she said she would open a case against the woman who insulted her.
"Women must let other women be. How I dress is no one's business and it doesn't make me less of a doctor."
Police confirmed to TimesLIVE that a case had been opened.