Approach to chronic pelvic pain (GYN): Clinical sciences

Chronic pelvic pain arises from pelvic and other structures in non-pregnant patients, and lasts more than 6 months. It can affect quality of life and negatively impact the ability to participate in other daily activities, such as school or work. In addition to physical pain, many patients have associated symptoms of anxiety, distress, or even depression.

The diagnosis of chronic pelvic pain is often difficult because there can be more than one condition causing it, and sometimes there’s overlap between several coexisting causes of pain. So be sure to complete the evaluation and don’t stop just because one possible etiology is found. Gynecologic causes include endometriosis, adenomyosis, leiomyomas, adnexal masses, and pelvic organ prolapse. On the other hand, non-gynecologic causes can be urinary, musculoskeletal, psychosocial, or gastrointestinal.

When a patient presents with chronic pelvic pain, the first step is to perform a focused history and physical examination, and obtain an hCG to assess for pregnancy. If hCG is positive, your patient is pregnant. Thus, consider diagnoses associated with pregnancy, such as ectopic pregnancy or musculoskeletal pain. On the other hand, if the hCG is negative, assess for causes of chronic pelvic pain.

Let’s start with gynecologic causes, and the first one is endometriosis. This is characterized by endometrium-like tissue outside of the endometrial cavity. A focused history may reveal the 4 “Ds” of endometriosis: dysmenorrhea, dyspareunia, dyschezia, or dysuria. These symptoms, as well as generalized pelvic pain, are often exacerbated by menses and can be cyclic in nature. On physical exam, you might find lower abdominal or pelvic tenderness, a pelvic mass, reduced uterine mobility, a tender posterior vaginal fornix, and rectovaginal nodularity. If this is the case, consider endometriosis. Next, obtain a pelvic ultrasound, and consider performing a diagnostic laparoscopy to confirm your diagnosis.

Here’s a clinical pearl! The definitive diagnosis of endometriosis is made with laparoscopy. However, given surgical risks and costs, many clinicians make a presumptive diagnosis of endometriosis based on clinical history, physical exam, and ultrasound.

If you see an endometrioma on ultrasound, or if the laparoscopy reveals an endometrioma, endometriotic implants, or scarring, this supports the diagnosis of endometriosis.

Here’s a high-yield fact! An endometrioma can also be referred to as a "chocolate cyst" because it contains old blood that, when expressed, looks like chocolate syrup.

Our next gynecologic cause is adenomyosis. Here, the glandular endometrial tissue extends into the uterine myometrium. The patient might report dysmenorrhea, heavy vaginal bleeding, and intermenstrual spotting. Physical exam findings may include lower abdominal or pelvic tenderness, and an enlarged globular uterus.

In this case, consider adenomyosis and obtain a pelvic ultrasound. If ultrasound shows a heterogeneous myometrium, myometrial cysts, and asymmetric myometrial thickness, the diagnosis is likely adenomyosis.

Next, consider leiomyomas, aka fibroids. These are common benign smooth muscle tumors. The history might reveal dysmenorrhea and heavy vaginal bleeding, as well as the sequelae of uterine enlargement, which includes pelvic pressure, low back pain, urinary frequency, and constipation. The physical examination might demonstrate abdominal or pelvic tenderness and an enlarged uterus with an irregular contour.

With these findings, consider a uterine leiomyoma and obtain a pelvic ultrasound. If ultrasound reveals an enlarged uterus with at least one myometrial mass, the likely diagnosis is a leiomyoma.

Here’s a high-yield fact! Uterine leiomyomas are the most common gynecologic pelvic neoplasm; but without surgical removal and histologic analysis, they’re difficult to distinguish from the rare but aggressive leiomyosarcoma. Most patients with leiomyosarcoma don’t have any predisposing risk factors; however some may have a hereditary cancer syndrome such as Li-Fraumeni or retinoblastoma, while others may have a history of pelvic radiation exposure or using tamoxifen for more than 5 years.

Okay, let’s move on to adnexal pathology. In this case, the patient may describe intermittent unilateral pain that’s indolent or progressive in nature. They may also report abdominal distension or bloating and pelvic pressure. Physical exam might reveal abdominal or pelvic tenderness and a pelvic mass.

In these patients, consider an adnexal mass and obtain a pelvic ultrasound. If the ultrasound demonstrates a cystic or solid adnexal mass, your diagnosis is either a benign or malignant adnexal mass. As a quick reminder, adnexal masses can be cystic or solid; simple or complex; as well as unilateral or bilateral.