documents in these young girls the pres cysts, which usually are less than 5 mm(with the exception of neonates, where they may be larger than 1 am). (7-9) The ovaries increase in size in prepubertal girls with follicles up to 1 cm in size. After menarche the ovaries are ovoid in shape and generally measure 3 x 2 x 1 to 2 am(Fig. 28-6). Follides typically are present. a study of ova rian size in women ofmenstrual age reveals a mean ovarian vol ume of 10 ml(10)(Table 28-4) lists the size and appearance of ovaries with respect to patientage [28.2 1 Figure -28-6 Normal ovary with multiple small follide Ovarian Cysts In the prolife rative phase ofthe menstrual cycle, multi ple small foldes are visualized, usually 1 am in diameter or less. A dominant foll icle develops in the mid cyo which measures up to 2 cm in diameter. After ovulation, the corpus luteumcyst develops [28.6] This frequently contains hemorrhage and hasa complex appearance (Table 28-5)descri bes the appearance ofovary follicles with respect to phase of the menstrual cycle. (Table 28-6)lists the various appearances of varian cystsare common in all age groups, but especially in women of menstrual age. Anechoic b enign cysts are completely anechoic with enhanced through transmission. They have a thin wall no septations, and no solid elements. Because dominant fol lices and luteal cysts frequendy are up to 3 cm in size. benign-appearing lesions in this size range require no follow-up Hemorrhagic cysts have a more complex appearance(see Table 28-6)with internal septation and retractile dot(Fig. 28-7).[28.7 However, if a cyst is small (less than 3 cm)and has the dassic appearance of a hemorrhagic cyst, it can be treated as a benign cyst and therefore does not requ ire follow-up Figure -28-7 Hemorrhagic cyst. Transva ginal view of the right ovary demonstrates a cyst with multiple internal echoes and strands of internalechoes. This is the classicappearance of a hemorhagiccyst. If a lesion has a questionable appearance or is larger than 3 am, serial scans are helpful since hemorrhagic cysts undergo rapid change of intemal cha racteristics A follow-up sonogram in 6 weeks(when the patient is at a different phase of the menstrual cycle)typically demonstrates resolution of the cyst For la rge lesions. ormonal therapy frequently is used to suppressfollicular activity and the development of new cysts(Table 28-7) Free fluid A small amount of fluid is present in the cul-de-sac of asymptomatic women throughout the menstrual cycle. The largest quantity of normal free fuid occurs after the mature fol licle ruptures in the midcyde, (11)but fluid also is seen during menstruation and can be visualized throughout the cycle from serosal transudate from the ovary or other peritoneal organs (12) Complex fluid(with debris or septations)is a and results from hemorhage, infection, or neoplasm SONOGRAPHIC PITFALLS Extrauterine Solid Pelvic Masses A variety of nonovarian tumors and other a bnomalities can masque rade as solid ovarian masses (Table 28-8). The most of these is the pedunculated fibroid(Fig. 28-8A and Fig. 28-8B). This diag nosis is made sonographic lly when the ovaries are seen separate fom the otherwise suspicious -a ppeanng mass A stalk can be present connecting the pedunculated fibroid to the uterus. Magnetic resonance imaging is helpful in difficult cases. Nongynecologic cond itions thatdocuments in these young girls the presence of cysts, which usually are less than 5 mm (with the exception of neonates, where they may be larger than 1 cm). (7-9) The ovaries increase in size in prepubertal girls with follicles up to 1 cm in size. After menarche, the ovaries are ovoid in shape and generally measure 3 x 2 x 1 to 2 cm (Fig. 28-6 ). Follicles typically are present. A study of ovarian size in women of menstrual age reveals a mean ovarian volume of 10 ml. (10) (Table 28-4 ) lists the size and appearance of ovaries with respect to patient age. [28.2 ] Figure - 28-6. Normal ovary with multiple small follicles. Ovarian Cysts In the proliferative phase of the menstrual cycle, multiple small follicles are visualized, usually 1 cm in diameter or less. A dominant follicle develops in the midcycle, which measures up to 2 cm in diameter. After ovulation, the corpus luteum cyst develops. [28.6] This frequently contains hemorrhage and has a complex appearance. (Table 28-5 ) describes the appearance of ovary follicles with respect to phase of the menstrual cycle. (Table 28-6 ) lists the various appearances of hemorrhagic cysts. Ovarian cysts are common in all age groups, but especially in women of menstrual age. Anechoic benign cysts are completely anechoic with enhanced through transmission. They have a thin wall, no septations, and no solid elements. Because dominant follicles and luteal cysts frequently are up to 3 cm in size, benign-appearing lesions in this size range require no follow-up. Hemorrhagic cysts have a more complex appearance (see Table 28-6 ) with internal septations and retractile clot (Fig. 28-7 ) . [28.7 ] However, if a cyst is small (less than 3 cm) and has the classic appearance of a hemorrhagic cyst, it can be treated as a benign cyst and therefore does not require follow-up. Figure - 28-7. Hemorrhagic cyst. Transvaginal view of the right ovary demonstrates a cyst with multiple internal echoes and strands of internal echoes. This is the classic appearance of a hemorrhagic cyst. If a lesion has a questionable appearance or is larger than 3 cm, serial scans are helpful since hemorrhagic cysts undergo rapid change of internal characteristics. A follow-up sonogram in 6 weeks (when the patient is at a different phase of the menstrual cycle) typically demonstrates resolution of the cyst. For large lesions, hormonal therapy frequently is used to suppress follicular activity and the development of new cysts (Table 28-7 ) . Free Fluid A small amount of fluid is present in the cul-de-sac of asymptomatic women throughout the menstrual cycle. The largest quantity of normal free fluid occurs after the mature follicle ruptures in the midcycle, (11) but fluid also is seen during menstruation and can be visualized throughout the cycle from serosal transudate from the ovary or other peritoneal organs. (12) Complex fluid (with debris or septations) is abnormal and results from hemorrhage, infection, or neoplasm SONOGRAPHIC PITFALLS Extrauterine Solid Pelvic Masses A variety of nonovarian tumors and other abnormalities can masquerade as solid ovarian masses (Table 28-8 ) . The most common of these is the pedunculated fibroid (Fig. 28-8A and Fig. 28-8B ) . This diagnosis is made sonographically when the ovaries are seen separate from the otherwise suspicious-appearing mass. A stalk can be present connecting the pedunculated fibroid to the uterus. Magnetic resonance imaging is helpful in difficult cases. Nongynecologic conditions that