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A 25-year-old nulligravid woman comes to the office due to continued pelvic and lower back pain. The pain has worsened over the past year. It is constant but intensifies a few days before the patient's menstruation and improves toward the end of her cycle. The patient has been in a monogamous relationship for the past 4 years. She started taking ibuprofen and combined oral contraceptives 9 months ago when she began having pelvic pain, and they have minimally improved her pain. Temperature is 37.2 C (99 F) and blood pressure is 120/78 mm Hg. BMI is 24 kg/m2. Examination shows tenderness in the posterior vaginal fornix, decreased uterine mobility, and thickening of the uterosacral ligaments. No adnexal masses are palpated. Urine β-hCG is negative. Hemoglobin is 12 g/dL and leukocytes are 8,200/mm3. Transvaginal ultrasound reveals normal pelvic anatomy.
Item 1 of 2
Which of the following is the best next step in evaluation of this patient?
Show Explanatory Sources
This patient most likely has endometriosis, the development of endometrial glands and stroma outside the uterus. During the menstrual cycle, the ectopic endometrial tissue proliferates and sheds, but because the tissue is located within the abdominopelvic cavity with no outlet, this creates inflammation, resulting in dysmenorrhea (ie, painful menses). With continued inflammation, patients can also develop adhesions, fibrosis, and subsequent distortion of the adjacent pelvic anatomy, resulting in classic examination findings such as posterior fornix tenderness, decreased uterine mobility, and uterosacral ligament thickening. Transvaginal ultrasound is often normal (except in those with an endometrioma) because lesions are too small to detect on imaging.
Initial treatment of endometriosis is with nonsteroidal anti-inflammatory drugs (which decrease inflammation) and combined oral contraceptive pills (which suppress ovulation and reduce menstruation). However, in patients who fail medical management, a diagnostic laparoscopy is recommended because it allows for definitive diagnosis (via direct visualization and biopsy of lesions) and is therapeutic (via removal of endometriotic lesions) (Choice E).
(Choice A) A CT scan cannot definitively diagnose endometriosis because the lesions are too small to visualize, and a CT scan is not indicated in patients with a normal pelvic ultrasound.
(Choice B) An endometrial biopsy can diagnose endometrial cancer, which typically presents in high-risk (eg, obese) patients with abnormal uterine bleeding or postmenopausal bleeding. It is not indicated in patients with dysmenorrhea and regular ovulatory menstrual cycles.
(Choice C) A hysterosalpingogram is used in the evaluation of female infertility. It assesses the uterine cavity for structural abnormalities (eg, intracavitary fibroids) and the fallopian tubes for obstruction, but it is not used to evaluate secondary dysmenorrhea.
Educational objective:
Endometriosis is initially treated with nonsteroidal anti-inflammatory drugs and combined oral contraceptives. Patients who fail medical therapy are recommended for laparoscopy, which can offer definitive diagnosis and treatment.