At CT and MRI, an<unk>  possesses characteristic appearance. It is typically large (12–25 cm) and has prominent solid components with cystic elements. It is usually filled with lipid constituents and therefore demonstrates fat density at CT and MRI. Ultrasound appearance of an<unk>  is nonspecific. It is highly heterogeneous with partially solid lesions and scattered calcifications. Stage Traditionally, comprehensive surgical staging is performed via exploratory laparotomy with cytologic washings, peritoneal biopsies, an omental assessment (either biopsy or rarely a full omentectomy), and both pelvic and aortic lymph node dissection. Laproscopy is often suggested as an alternative to surgically stage patients with<unk> . Ovarian cancer is staged using the FIGO staging system and uses information obtained after surgery, which can include a total abdominal hysterectomy via midline laparotomy, unilateral (or bilateral) salpingo-oophorectomy, pelvic (peritoneal) washings, assessment of retroperitoneal lymph nodes and/or appendectomy. The AJCC staging system, identical to the FIGO staging system, describes the extent of tumor (T), the presence of absences of metastases to lymph nodes (N), the presence or absence of distant metastases (M). +Table 1: FIGO Staging System for Ovarian Cancers Stage Description I Cancer is completely limited to the ovary IA involves one ovary, capsule intact, no tumor on ovarian surface, negative washings IB involves both ovaries; capsule intact; no tumor on ovarian surface; negative washings IC tumor involves one or both ovaries IC1 surgical spill IC2 capsule has ruptured or tumor on ovarian surface IC3 positive ascites or washings II pelvic extension of the tumor (must be confined to the pelvis) or primary peritoneal tumor, involves one or both ovaries IIA tumor found on uterus or fallopian tubes IIB tumor elsewhere in the pelvis III cancer found outside the pelvis or in the retroperitoneal lymph nodes, involves one or both ovaries IIIA metastasis in retroperitoneal lymph nodes or microscopic extrapelvic metastasis IIIA1 metastasis in retroperitoneal lymph nodes IIIA1(i) the metastasis is less than 10 mm in diameter IIIA1(ii) the metastasis is greater than 10 mm in diameter IIIA2 microscopic metastasis in the peritoneum, regardless of retroperitoneal lymph node status IIIB metastasis in the peritoneum less than or equal to 2 cm in diameter, regardless of retroperitoneal lymph node status; or metastasis to liver or spleen capsule IIIC metastasis in the peritoneum greater than 2 cm in diameter, regardless of retroperitoneal lymph node status; or metastasis to liver or spleen capsule IV distant metastasis (i.e. outside of the peritoneum) IVA pleural effusion containing cancer cells IVB metastasis to distant organs (including the parenchyma of the spleen or liver), or metastasis to the inguinal and extra-abdominal lymph nodes Pathology Ovarian tumors by incidence and risk of ovarian cancer, with<unk>  at right. An<unk>  contains varying compositions of adult and embryonic tissue. The most common embryonic component identified in<unk> s is the neuroectoderm. Occasionally, tumors may present neuroepithelium that resemble neuroblasts. Tumors may also present embryonic components such as<unk>  cartilage and skeletal muscle of mesodermal origin.<unk> s composed of embryonic endodermal derivatives are rare. Often a mature cystic<unk>  is misdiagnosed as its<unk>  counterpart due to the misinterpretation of mature neural tissue as<unk> . While mature neural cells have nuclei with uniformly dense chromatin and neither exhibit apoptotic or mitotic activity,<unk>  neural cells have nuclei with vesicular chromatin and exhibit both apoptotic and mitotic activity. A recent study has identified the use of Oct-4 as a reliable biomarker for the diagnosis of highly malignant cases of<unk> s. Grade Thurlbeck and Scully devised a grading system for “pure”<unk> s on the basis of differentiation of the cellular elements of the tumor. The proportion of<unk>  tissue elements defines the grade of<unk> ty. This was later modified by Norris et al. (1976), who added a quantitative aspect to the degree of<unk> ty. +Table 2: Identifying Tumor Grade in<unk> s Grade Thurlbeck and Scully (1960) Norris et al. (1976) 0 All cells are well differentiated All cells are mature; mitotic activity is rare or absent. 1 Cells are well differentiated except in rare small foci of embryonic tissue; neuroepithelium is absent or rare Neuroepithelium absent or limited to fewer than one low-magnification field (x40) per slide 2 Moderate quantities of embryonic tissue present; cells show atypicality and mitotic activity Neuroepithelium does not exceed more than three low-magnification fields (x40) per slide 3 Large quantities of embryonic tissue present; cells show atypicality and mitotic activity Neuroepithelium exceeds more than three low-magnification fields (x40) per slide Karyotype An ovarian<unk>  is karyotypically normal 46,XX or near-normal. Grade 1 or 2 tumors exhibit 46,XX normal karyotype, whereas grade 3 tumors show a variety of abnormal karyotypes. Though<unk>  cells show a normal karyotype, there may still be detectable alterations in the gene level and that these aberrations may influence the stability of chromosome status.
Immature teratoma
Teratoma
Ovarian fibroma
Embryonal carcinoma
Gonadoblastoma
Dysgerminoma
Mucinous cystadenoma
Luteoma