What is the most appropriate diagnostic test for a 28-year-old nulligravid woman with a 7-cm septated left adnexal mass and severe dysmenorrhea?

Laparoscopy is the Most Appropriate Diagnostic Test for This Patient

Laparoscopy is the most appropriate diagnostic test for this 28-year-old nulligravid woman with a septated adnexal mass, progressive dysmenorrhea, and findings suggestive of endometriosis.

Clinical Presentation Analysis

This patient presents with several concerning features:

• Progressive severe dysmenorrhea over 6 months
• Fixed, retroverted uterus on examination
• Nodularity in the cul-de-sac
• 7-cm septated left adnexal mass confirmed by transvaginal ultrasound
• Persistent mass size on follow-up ultrasound after 4 weeks

Diagnostic Approach Based on Evidence

Why Laparoscopy is Indicated:

1. Clinical features highly suggestive of endometriosis:

   • The combination of progressive dysmenorrhea, fixed retroverted uterus, and cul-de-sac nodularity strongly suggests endometriosis
   • Endometriosis is a common cause of adnexal masses in young women and requires direct visualization for definitive diagnosis 1

2. Characteristics of the adnexal mass:

   • The 7-cm septated mass has persisted for at least 4 weeks
   • Septated appearance on ultrasound increases suspicion for potential malignancy
   • According to guidelines, adnexal masses larger than 6 cm warrant referral to a gynecologist for further evaluation 2

3. Limitations of other imaging modalities:

   • While MRI can characterize indeterminate adnexal masses, it cannot provide definitive tissue diagnosis 3
   • CT has limited soft tissue discrimination in the adnexal region 3
   • Measurement of CA-125 has poor specificity, especially in premenopausal women 2

Evidence-Based Rationale:

According to the ACR Appropriateness Criteria, when an adnexal mass has concerning features (septations, size >6 cm) and clinical findings suggest endometriosis, direct visualization is needed for both diagnosis and potential treatment 3.

Laparoscopy remains the gold standard for diagnosing and staging endometriosis 1, which is strongly suspected in this case based on the clinical presentation.

Why Other Options Are Less Appropriate:

1. CA-125 measurement (Option A):

   • Low specificity in premenopausal women
   • Elevated in many benign conditions including endometriosis
   • Cannot differentiate between benign and malignant masses reliably 2

2. Barium enema (Option B):

   • Not indicated for evaluation of adnexal masses
   • No role in primary evaluation of gynecologic pathology

3. CT scan (Option C):

   • Limited soft tissue discrimination in adnexal region
   • Not recommended as first-line imaging for characterization of adnexal masses 3

4. MRI (Option D):

   • While useful for characterizing indeterminate masses, this patient already has clinical findings highly suggestive of endometriosis
   • MRI cannot provide tissue diagnosis or therapeutic intervention
   • Would delay definitive diagnosis and potential treatment

Management Algorithm:

1. For premenopausal women with adnexal masses >6 cm with septations and clinical findings suggestive of endometriosis:

   • Initial evaluation with transvaginal ultrasound (already completed)
   • If persistent after 4-6 weeks (confirmed in this case)
   • Proceed to laparoscopy for definitive diagnosis and potential treatment

2. For indeterminate masses without clinical findings suggestive of specific pathology:

   • Consider MRI pelvis with and without contrast
   • Measure CA-125 if malignancy is suspected

Important Clinical Caveat:

Laparoscopy offers both diagnostic and therapeutic benefits in this case. If endometriosis is confirmed, treatment can be initiated during the same procedure, potentially improving the patient's quality of life by addressing her progressive dysmenorrhea.