Pathology of the Ovaries - Ultrasound Review

Flashcards cover ovarian anatomy, normal ultrasound appearance, phases of the ovarian cycle, Doppler indices, and a range of benign and malignant ovarian pathologies (cysts, endometriosis, OHSS, PCOS, torsion, paraovarian/peritoneal cysts) with typical ultrasound features and management cues.

Where are the ovaries typically located in relation to the uterus and iliac vessels?

Paired almond-shaped organs near the lateral pelvic wall; position varies with uterine location; they are medial to the external iliac artery and anterior to the internal iliac artery, suspended from the broad ligament.

What is the normal sonographic appearance of the ovaries?

Homogeneous echotexture with a central echogenic medulla; small anechoic follicles located peripherally in the cortex; appearance varies with age and menstrual cycle.

Name the three sonographic phases of the ovarian cycle in reproductive-age women.

Follicular (proliferative) phase, ovulation, and luteal (secretory) phase.

What is the typical size of the dominant follicle just before ovulation?

About 2.5 cm (roughly 2.0–2.5 cm at ovulation).

What is a cumulus oophorus sign and what does it indicate?

A small eccentric mural protrusion (about 1 mm) into the follicular lumen; its visualization indicates a mature follicle and imminent ovulation, though it is not always reproducible.

What sonographic signs indicate ovulation has occurred?

Disappearance or marked decrease in follicle size, appearance of echogenic echoes in the follicle, irregular follicle wall, free fluid in the pouch of Douglas, and secretory changes in the endometrium.

What may happen to nondominant follicles after ovulation?

Fluid may be reabsorbed slowly; a follicular cyst can develop if nondominant fluid is not resorbed; dominant follicle usually ruptures and disappears.

Describe the corpus luteum and its role after ovulation.

A transformed follicle that becomes corpus luteum; vascularized and produces progesterone to sustain early pregnancy until placental takeover at 10–12 weeks gestation; typically regresses before the next cycle.

What days correspond to the follicular, ovulatory, and luteal phases in a typical 28-day cycle?

Follicular: days 1–13; Ovulation: day 14; Luteal: days 15–28.

Which endometrial and ovarian changes accompany the proliferative (follicular) phase?

Follicles develop in the ovary; endometrium thickens under estrogen influence; dominant follicle reaches about 2.0–2.5 cm by ovulation.

What is the normal postmenopausal ovarian appearance and volume threshold considered abnormal?

Ovaries are often difficult to visualize due to atrophy; ovarian volume >8 ml is considered abnormal in postmenopausal women.

How is ovarian volume calculated?

Volume = Length × Width × Height × 0.523; volumes >22 ml are abnormal during menstrual years; a volume more than twice that of the opposite ovary is suspicious.

What hormones do the ovaries synthesize and convert, and what do they produce after ovulation?

Ovaries synthesize androgens and convert them to estrogens; after ovulation, they produce progesterone to support early pregnancy until the placenta takes over.

What is the Doppler Resistive Index (RI) and how is it calculated?

RI = (Peak Systolic Velocity − End Diastolic Velocity) / Peak Systolic Velocity.

What is the Pulsatility Index (PI) and how is it calculated?

PI = (Peak Systolic Velocity − End Diastolic Velocity) / Mean Velocity.

Which Doppler finding is commonly associated with neovascularity and possible malignancy?

Increased diastolic flow leading to lower RI/PI values; indices vary, with some suggesting RI > 0.4 or PI > 1 as normal in nonfunctioning ovaries.

What is the typical ultrasound sign for hemorrhagic ovarian cysts with color Doppler?

“Ring of fire” sign: circumferential color flow around a cystic hemorrhagic component indicating vascularized cyst wall.

What are simple cystic ovarian masses characterized by on ultrasound?

Thin, smooth walls; anechoic contents; acoustic (posterior) enhancement.

What is a paraovarian cyst and where is it located?

A simple cyst adjacent to the ovary, often arising from Wolffian duct remnants, located in the broad ligament.

What is a peritoneal inclusion cyst and its typical clinical setting?

Mesothelial-lined cyst formed when adhesions trap peritoneal fluid around the ovaries; occurs after surgery, PID, trauma, or endometriosis; presents with pelvic pain or mass.

What is an ovarian torsion and why is it a surgical emergency?

Partial or complete rotation of the ovarian pedicle causing compromised venous/lymphatic drainage, edema, infarction; commonly involves the ovary and fallopian tube.

What is the ultrasound sign of twisted pedicle in ovarian torsion?

“Whirlpool” sign: twisted pedicle seen on color Doppler and/or gray-scale ultrasound; highly specific but not highly sensitive.

How does endometriosis differ from adenomyosis?

Endometriosis is ectopic endometrial tissue outside the uterus; adenomyosis is endometrial tissue within the myometrium.

What is an endometrioma (chocolate cyst) on ultrasound?

Ovarian endometriosis presenting as a cystic mass with variable echogenicity due to blood products; can be unilocular or multilocular with diffuse low-level internal echoes.

What ultrasound features raise concern for ovarian malignancy?

Cysts with irregular walls, thick or irregular septations, mural nodules, solid echogenic components, invasion to surrounding structures, ascites, or evidence of metastasis.

What features favor benign ovarian pathology on ultrasound?

Well-defined, smooth-walled, unilocular, simple cysts; thin walls; absence of solid components or thick septations; no papillary projections.

What is a benign adnexal cyst, and which examples are most common?

Functional ovarian cysts (follicular, corpus luteum, hemorrhagic, theca-lutein) and simple cysts; other benign cysts include paraovarian and peritoneal inclusion cysts.

Describe follicular cysts and their typical clinical course.

Dominant follicle fails to ovulate; usually unilateral; thin-walled, translucent, clear fluid; may reach up to 20 cm; often asymptomatic and resolve spontaneously.

Describe corpus luteum cysts and their typical clinical setting.

Result from failed resorption or hemorrhage within mature corpus luteum; cysts are cystic and can be associated with pregnancy; may show internal echoes and a ring-like peripheral color pattern.

Describe hemorrhagic cysts on ultrasound.

Intracystic hemorrhage within a functional cyst; variable internal echoes; often mimics solid mass; may show posterior acoustic enhancement.

Describe Theca-Lutein Cysts.

Large, bilateral, multiloculated cysts; associated with high hCG levels (trophoblastic disease, multiple gestations, fertility treatment).

What is Ovarian Hyperstimulation Syndrome (OHSS) and its ultrasound findings?

A complication of fertility treatment with bilateral ovarian enlargement (often >5 cm in mild cases; >10 cm in severe cases) and possible ascites or pleural effusions; resolves after treatment.

What ultrasound features are typical of polycystic ovarian syndrome (PCOS)?

Bilateral enlarged ovaries with multiple tiny peripheral follicles giving a “string of pearls” appearance; sometimes the ovary is normal size or enlarged.

What is postpartum ovarian remnant syndrome?

Residual functioning ovarian tissue left after oophorectomy, which can form cysts.

What is the significance of an ovarian mass with doubtful distinguishing features in the setting of prior surgery?

Consider peritoneal inclusion cysts or paraovarian cysts; correlate with history and Doppler findings to differentiate from ovarian origin.

What imaging features suggest a postmenopausal ovary is malignant rather than benign?

Ovaries that are enlarged with abnormal echogenicity, especially if accompanied by solid components or suspicious nodules; ovaries may be difficult to visualize, so any discrete mass in a postmenopausal patient is concerning.

What is the role of Doppler in evaluating adnexal masses?

Helps differentiate benign from malignant lesions: benign lesions typically show higher resistance and limited vascularity; malignant lesions often show low-resistance, high diastolic flow due to neovascularization; RI/PI values vary with cycle and condition.

Name two common epithelial ovarian tumors and their general character.

Cystadenoma (benign) and cystadenocarcinoma (malignant); serous type often presents with multiple cysts; larger solid components increase suspicion for malignancy.

What is an adnexal mass’s evaluation priority on ultrasound according to the notes?

Assess cystic vs solid composition, presence of septations or mural nodules, wall characteristics, vascularity on Doppler, and correlation with clinical findings for malignancy risk.