<s>[INST] context: Teratoma

Teratomas are divided into three categories:

(1) Mature (benign)

Most benign teratomas are cystic and are known as dermoid cysts.
These neoplasms are presumably derived from the ectodermal differentiation of totipotential cells.
They are bilateral in 10% to 15% of cases.
Characteristically, they are unilocular cysts containing hair and cheesy sebaceous material. On section, they reveal a thin wall lined by an opaque, grey-white, wrinkled, apparent epidermis.
Generally, in one area of the cyst wall, a solid prominence is seen known as Rokitansky's protuberance where tissue elements such as tooth, bone, cartilage & various other odd tissues are present.
On histologic examination, the cyst wall is composed of stratified squamous epithelium with underlying sebaceous glands, hair shafts, and other skin adnexal structures. In most cases, structures from other germ layers can be identified, such as cartilage, bone, thyroid tissue, and other organoid formations.
Dermoid cysts are sometimes incorporated within the wall of a mucinous cystadenoma.
About 1% of the dermoids undergo malignant transformation of any one of the component elements ( but most commonly, squamous cell carcinoma).

(2) Monodermal or Specialized Teratomas

The rare group of tumors, the most common of which are struma ovarii and carcinoid.
They are always unilateral, although a contralateral teratoma may be present.
Struma ovarii is composed entirely of mature thyroid tissue. Interestingly, these thyroidal neoplasms may hyperfunction, causing hyperthyroidism.
The ovarian carcinoid, which presumably arises from intestinal epithelium in a teratoma, might, in fact, be functioning, particularly in large tumors, producing 5-hydroxytryptamine and the carcinoid syndrome.

(3) Immature Malignant Teratomas

These are rare tumors that differ from benign teratomas in that the component tissue resembles that observed in the fetus or embryo rather than in the adult.
The tumor is found chiefly in prepubertal adolescents and young women.
These grow rapidly and frequently penetrate the capsule with local spread or metastases.
On microscopy, there are varying amounts of immature tissue differentiating toward cartilage, glands, bone, muscle, nerve, and others.
An important risk for the subsequent extraovarian spread is the histologic grade of tumor, which is based on the proportion of tissue containing immature neuroepithelium. [/INST] question: Rokitansky protuberances are seen in - | options: A: Mucinous carcinoma B: Teratoma C: Epidermal cystoids adenoma D: Papillary carcinoma | answer: B </s>