Diagnostic Approach for Lower Abdominal Mass in Reproductive-Age Women

Ovarian and Adnexal Masses

Benign cystic teratoma is the most common ovarian neoplasm in women of reproductive age and can be diagnosed by ultrasound showing echogenic attenuating components or small horizontal interfaces, according to the American College of Radiology 1, 2
Fibrothecoma tumors can present as solid adnexal masses and are usually diagnosable on ultrasound, as recommended by the American College of Radiology 1
Hemorrhagic cysts demonstrate spiderweb-appearing or retracting clot with peripheral vascularity on ultrasound, as described by the American College of Radiology 1, 2
Endometriomas show low-level internal echoes, mural echogenic foci, or nonvascular solid attenuating components, according to the American College of Radiology 1, 2, 3
Peritoneal inclusion cysts take the shape of underlying pelvic spaces and are located adjacent to or surrounding a functioning ovary, as noted by the American College of Radiology 1, 2
Hydrosalpinx appears as a tubular cystic mass with or without folds on ultrasound, as described by the American College of Radiology 1, 2, 3

Pedunculated or broad ligament fibroids are the most common solid adnexal masses in the nonacute setting and can be mistaken for ovarian masses, according to the American College of Radiology 1, 2, 3
Leiomyosarcoma comprises 1.7% of women undergoing hysterectomy for presumed fibroids in their seventh decade but is extremely rare in premenopausal women, as reported by the Environmental Health Perspectives 4
Risk of leiomyosarcoma increases significantly with postmenopausal status and rapid tumor growth, as noted by the American College of Obstetricians and Gynecologists 5
MRI with diffusion-weighted imaging is the most effective preoperative imaging modality for distinguishing leiomyosarcoma from benign leiomyoma, as recommended by the American College of Radiology 6, 5, 7

Transvaginal ultrasound with color Doppler is the essential first-line examination, with 90-99% sensitivity and 98% specificity for detecting fibroids, according to the American College of Radiology 7
Pelvic MRI with diffusion-weighted imaging should be performed when ultrasound findings are suspicious, inconclusive, or when malignancy cannot be excluded, as recommended by the American College of Radiology 6, 7
Diffusion-weighted sequences improve sensitivity and specificity for detecting malignancy, with up to 100% sensitivity and specificity for leiomyosarcomas, as reported by the American College of Radiology 7
The IOTA Simple Rules for Risk Stratification achieve 93% sensitivity and 81% specificity for predicting malignancy, as described by the American College of Radiology 1, 2

Avoid morcellation procedures when malignancy cannot be excluded, as tumor spillage dramatically worsens prognosis if leiomyosarcoma is present, as warned by the American College of Obstetricians and Gynecologists 5
Carefully identify both ovaries during ultrasound examination to avoid misdiagnosing pedunculated fibroids as ovarian masses, as recommended by the American College of Radiology 1, 2
Consider age and menopausal status as critical risk factors; postmenopausal women with growing masses warrant heightened suspicion for malignancy, as noted by the American College of Obstetricians and Gynecologists 5
Recognize that simple cysts have <0.4% malignancy risk in premenopausal women, establishing a benign process in 98.7% of cases, as reported by the American College of Radiology 1, 2, 3