Malignant (immature) teratomas are found early in life, the mean age at clinical detection being 18 years. They typically are bulky and appear solid on cut section, and they often contain areas of necrosis; uncommonly, cystic foci are present that contain sebaceous secretion, hair, and other features similar to those of mature teratomas. On microscopic examination, the distinguishing feature is the presence of immature elements or minimally differentiated cartilage, bone, muscle, nerve, or other tissues. As with other tumors, the prognosis depends on grade and stage.
A rare subtype of teratoma is composed entirely of specialized tissue. The most common example is struma ovarii, http://ebooksmedicine.net
Twotypesofepithelialcells:cytotrophoblastPrimaryfocusmaydegenerate,andsyncytiotrophoblastleavingonlymetastasesResistanttochemotherapy which is composed entirely of mature thyroid tissue that may actually produce hyperthyroidism. These tumors appear as small, solid, unilateral brown ovarian masses. Other specialized teratomas include ovarian carcinoid, which in rare instances produces carcinoid syndrome.
With all ovarian neoplasms, management poses a formidable clinical challenge, because symptoms or signs usually appear only when tumors are well advanced. Ovarian tumors of surface epithelial origin usually are asymptomatic until they become large enough to cause local pressure symptoms (e.g., pain, gastrointestinal complaints, urinary frequency). Indeed, about 30% of all ovarian neoplasms are discovered incidentally on routine gynecologic examination. Larger masses, particularly the common epithelial tumors, may cause an increase in abdominal girth. Smaller masses, particularly dermoid cysts, sometimes twist on their pedicles (torsion), producing severe abdominal pain that mimics an acute abdomen. Metastatic seeding of malignant serous tumors often causes ascites, whereas functioning ovarian tumors often come to attention because of the endocrinopathies they produce.
Fig.19.18Maturecysticteratoma(dermoidcyst)oftheovary.Aballofhair(bottom)andamixtureoftissuesareevident.(Courtesy of Dr. Christopher Crum, Brigham and Women’s Hospital, Boston, Massachusetts.)
Unfortunately, treatment of ovarian tumors remains unsatisfactory; only a modest increase in survival has been achieved since the mid-1970s. Screening methods that detect early tumors are badly needed, but those evaluated to date are of limited value. One such marker, the protein CA-125, is elevated in the sera of 75% to 90% of women with epithelial ovarian cancer. However, CA-125 is undetectable in up to 50% of women with cancer limited to the ovary; conversely, it often is elevated in a variety of benign conditions and nonovarian cancers. Hence, its usefulness as a screening test in asymptomatic post-menopausal women is limited. Currently, CA-125 measurements are of greatest value in monitoring response to therapy.
http://ebooksmedicine.net
Tumorsmayarisefromepithelium,sexcord–stromalcells,orgermcells.
Epithelialtumorsarethemostcommonmalignantovariantumorandaremorecommoninwomenolderthan40yearsofage.
Themajortypesofepithelialtumorsareserous,mucinous,andendometrioid.Eachhasabenign,malignant,andborderlinecounterpart.
Serouscarcinomaisthemostcommonandmanyariseinthedistalfallopiantube.
Sexcord–stromaltumorsmaydisplaydifferentiationtowardgranulosa,Sertoli,Leydig,orovarianstromalcelltype.Dependingondifferentiation,theymayproduceestrogensorandrogens.
Germcelltumors(mostlycysticteratomas)arethemostcommonovariantumorinyoungwomen;thevastmajorityarebenign.