An ovarian neoplasm in a 15l4 year old girl is most likely to be

Refer Robbins page no 1029 Benign teratomas are bilateral in 10% to 15% of cases. Characteristically they are unilocular cysts containing hair and sebaceous material (Fig. 22-38). Sectioning reveals a thin wall lined by an opaque, gray-white, wrinkled epidermis, frequently with protruding hair shafts. Within the wall, it is common to find grossly evident tooth structures and areas of calcification. Microscopically, the cyst wall is composed of stratified squa- mous epithelium with underlying sebaceous glands, hair shafts, and other skin adnexal structures (Fig. 22-39). In most cases tissues from other germ layers can be identified, such as cailage, bone, thyroid, and neural tissue. Dermoid cysts are sometimes incorporated within the wall of a mucinous cystad- enoma. About 1% of the dermoids undergo malignant transformation, most commonly to squamous cell carci- noma, but also to other cancers as well (e.g., thyroid carcinoma, melanoma)