Prior to 1990, NIH Criteria⁶ of 1992 (1) chronic oligo-anovulation and (2) evidence of androgen excess (hirsutism & acne; male pattern alopecia; elevated testosterone) for which there is no other cause; and the Rotterdam Criteria⁶ of 2006 add (3) presence of polycystic ovaries...this increased the diagnoses by 50%. Some would add (4) insulin resistance (only about 50% have insulin resistance⁵). Only a fraction of women with polycystic ovaries have PCOS. Of all women with "insulin resistance", not all have PCOS⁵. It is the most common endocrine disorder in women and the most common cause of female infertility⁵! 5-10% of women (about 3.5-5 million reproductive-age women in USA). [PCOS website] Polycystic ovary syndrome; Stein-Leventhal syndrome (or polycystic ovary disease):  Women with PCOS (POD or PCOD) have normal reproductive organs, otherwise (such as the uterus and fallopian tubes). Their ovaries usually contain about 10 or more small cysts located at the periphery of the ovary. The size of these cysts generally are less than 8 mm and can be detected by ultrasound examination. These cysts do not appear to grow and usually remain small. They do not require surgical removal. Additionally, these cysts do not represent cancer and are not associated with an in-creased risk of ovarian cancer.

The reason we should recognize PCOS ovaries in general surgical pathology is because of the associated features of androgen excess (with unopposed estrogen increasing risk of endometrial cancer), insulin resistance, obesity, higher risk of diabetes and CHD...some having dyslipidemia and hypertension (qualifying for the "metabolic syndrome").

Polycystic ovaries typically exhibit 3 characteristics on sonographic examination: bilateral enlarged ovaries, multiple small cystic follicles ("pearl necklace sign" or "string of pearls"), and increased stromal echogenicity; and, since 20-30% of women have polycystic ovaries at U/S⁵, not all polycystic cases are PCOS:

1. Usually, the ovaries are enlarged symmetrically. The shape changes from ovoid to spherical. Ovarian volume can increase by as much as 6 mL; however, almost 30% of patients with a biochemical and pathologic diagnosis of polycystic ovaries have no increase in ovarian volume by U/S.
2. The typical polycystic ovary contains numerous cystic follicles at any given time. The follicles are small, sized 0.5-0.8 cm, and no dominant follicle is present. Characteristically, the follicles are peripherally located in the cortex; however, they can occur anywhere in the ovarian parenchyma. The U/S diagnosis of polycystic ovaries should be reserved for patients with at least 5 of these follicles in each ovary.
3. Typically, the ovaries are hypoechoic in relation to the surrounding pelvic fat and myometrium. Polycystic ovaries often display increased echogenicity; however, as many as one third may remain isoechoic or hypoechoic relative to the myometrium.

Pathology: Usually bilateral, smooth surfaced, whitish surfaced ovaries with multiple (5 or more per ovary) 5-8 mm cysts, usually peripheral. Outer cortex often seems fibrotic, collagenized; about 30% of cases have a corpus luteum or two on cut surface; and the multiple cysts are there..."sclerocystic ovaries"[LMC-03-6642]. Ovaries usually, not always, enlarged; medullary stroma with few to no signs of previous ovulation. Most of the cystic follicles are poor in granulosa lining cells & prominent in luteinized theca interna cells. Often have cortical & medullary stromal hyperplasia, sometimes with hyperthecosis. Endometrium varies from a hypoactive or proliferative to cystic hyperplasia to atypical hyperplasia, a low percentage having adenocarcinoma (usually well differentiated).

Other entities with numerous small follicular ovarian cysts:

• Ovarian folliculo-stromal "hyperreactio luteinalis" (HL): multiple theca-lutein cysts and/or thecosis (with or without luteinization) of ovarian stroma which may luteinized (and may or may not have a yellow color on cut surface) & may cause virilization in mother and/or the newborn (eg., ambiguous genitalia [L07-8857]); seen where high levels of HCG (hydatidiform mole, choriocarcinoma, fetal hydrops, & multiple gestations, and rare single gestation [in PCOS with a dermoid L07-8857]).
• Ovarian hyperstimulation syndrome: like HL; but when woman is being induced to ovulation with FSH followed by HCG or rarely by clomiphene alone.
• Juvenile hypothyroidism: 75% of these girls have multicystic ovaries.
• polycystic at onset of puberty: most soon revert to normal.
• Premature infants: may have multicystic ovaries.
• Congenital deficiency of 17-hydroxylase: patient has absence of sexual maturation and primary amenorrhea.
• sclerocystic ovaries, secondary causes (anything causing chronic oligo-anovulation in the premenopausal women): adrenal hyperplasias & adenomas & virilizing adrenal tumors; primary hypothalamic-pituitary disorders (especially when prolactin is elevated); and ovarian lesions producing excessive levels of estrogens or androgens (thereby cause virilization and maybe even be basis for androgenetic alopecia, sometimes), such as ovarian stromal hyperplasia (SH) and stromal hyperthecosis (HT...if much luteinization, cut surface may look yellowish)...SH usually in 6th & 7th decades and noted in 33% of autopsies in that age group. HT in 6th to 9th decades and noted in 33% of autopsies in that age group. Ovaries from normal to enlarged & cut surface of firm white to amber to yellow tissue ([LMC-03-5122; LMC-04-1035]; lmc-04-6303). Stroma may be just thecomatous or may show variable luteinization with clear to foamy cytoplasm. (LMC-03-5221; LMC-03-5811; LMC-03-6092; LMC-03-8735; LMC-04-2460). May see after cessation of long-term oral contraceptive use; may see in instances of periovarian adhesions

References:

1. Blaustein's Pathology of the Female Genital Tract, 4th Ed., 1994.
2. Atlas of Gynecologic and Obstetric Diagnostic Pathology, Janovski NA & Dubrausky V,  1967.
3. Sternberg (pathology textbook).
4. NEJM 2005
5. J. of Clinical Outcomes Management, 12(4):218, April 2005.
6. Legro RS, "Clinical Crossroads" section, JAMA 297(5):509-519, 7 February 2007.

(posted 19 May 2003; latest additions 10 October 2007)