Trichoadenoma in a mature cystic teratoma: a rare finding

Skin adnexal tumors arising in dermoid cysts of the ovary are exceedingly rare. We report a trichoadenoma arising in a dermoid cyst in a 42-year-old female. The histopathology of trichoadenoma has also been described briefly. Mature teratomas, which are almost all cystic (dermoid cysts), account for approximately 25% of all ovarian tumors, and 30% of benign ovarian tumors. They usually develop in children or women of the reproductive age group. Histologically, they are composed of variable proportions of tissue originating from the ectoderm, mesoderm, and endoderm. Cystic cavities are lined by mature epidermis. Although skin appendages and neural tissue are extremely common, there are only few case reports of skin adnexal tumors arising in a mature teratoma. We report a case of ovarian teratoma with a trichoadenoma. To the best of the authors' knowledge, this is the first report describing this rare benign skin adnexal tumor, in a mature cystic teratoma of the ovary.