Acute pelvic pain is an exceedingly common complaint. In the most recent, nationally representative data from Emergency Department (ED) use in the United States, the most common reason for an emergency room visit by females aged 15 to 64 years old (5.5 million visits) was for abdominal pain, cramps, or spasms. This was also the most common complaint in female patients aged 65 years and older.¹ This chapter will review the general approach to the ED patient with pelvic pain, followed by details on individual gynecologic conditions that may present with pelvic pain. The diagnosis and management of ectopic pregnancy is discussed in Chapter 54.

The list of conditions that may present with pelvic pain is intimidatingly long and includes diagnoses associated with significant morbidity and mortality risks (Table 55-1). The close proximity of the female pelvic organs and their visceral innervations mean that vague, poorly localized and/or referred pain is often present. The first step in the assessment is to determine the stability of the patient, and if she proves unstable, to help ED staff determine the interventions necessary to stabilize her condition. This may include the recognition of a surgical emergency, such as a ruptured ectopic pregnancy, followed by immediate surgical intervention. More commonly, however, the patient is stable, and it is best to start with a full, broad differential diagnosis.

The history of present illness, risk factors, review of systems, and abdominal and pelvic examination make each item on the differential more or less likely, narrowing and focusing the differential to a manageable level and guiding laboratory and imaging workup. It is particularly useful to figure out early in the encounter whether the pain is truly acute, as opposed to an exacerbation of chronic pelvic pain, because the latter can lead to an entirely different differential diagnosis. Box 55-1 lists the diagnostic process when presented with a patient with acute pelvic pain.

OVARIAN CYSTS

Definition

Ovarian cysts are fluid-filled structures that can form as part of a physiologic or pathologic process. Such cysts are considered simple if completely anechoic upon ultrasound. A simple cyst of < 3 cm diameter in a reproductive-aged woman is considered an ovarian follicle, and this finding is completely normal. Cysts with internal septae, solid components, or both are considered complex.

Pathophysiology

Physiologic ovarian follicles and cysts form as part of the cyclic ovulatory process. However, luteal cysts can persist or enlarge; the levonorgestrel intrauterine device (IUD) can increase the risk of luteal cyst persistence. While ovarian cysts can be normal, cyst rupture can cause acute pelvic pain and is often suspected when free fluid is found in the posterior cul-de-sac.

Differential Diagnosis

The differential diagnosis of ovarian cysts includes luteal cysts, hemorrhagic cysts, endometriomas, dermoid cysts, peritoneal inclusion cysts, paratubal cysts, hydrosalpinx, and malignant adnexal masses. A patient with acute pain in the setting of an ovarian cyst should be evaluated for ovarian torsion, which is discussed in the following section. Other causes of pain due to ovarian cysts include a ruptured cyst, distension of tubal tissue, mass effect from a large cyst, and complications of malignancy.

Evaluation

While most ovarian cysts are benign, patients should be evaluated for their risk of malignancy. The most important risk factors for ovarian cancer are age and a family history of ovarian, breast, or colon cancer; BRCA mutations and Lynch syndrome also carry significant risks of ovarian malignancy.

Symptoms

Acute onset of pain with peritoneal signs can signal rupture of an ovarian cyst. Mass effect from a cyst can lead to sensations of pelvic pressure and frequent urination. Complaints of dysmenorrhea, dyschezia, and dyspareunia may be associated with endometriosis and endometrioma. Concerning symptoms of malignancy include weight changes, bloating, early satiety, increased abdominal girth, and abnormal uterine bleeding or postmenopausal bleeding, which can occur secondary to increased estrogen levels associated with sex-cord stromal tumors.²

Physical Exam Findings

A complete abdominal and pelvic exam should be performed. Peritoneal signs may be present if rupture has led to peritoneal irritation. A large cyst may be palpable upon bimanual exam. Evaluation of groin lymph nodes should be done as well, especially if suspicion for malignancy exists.

Laboratory Findings

Anemia may be demonstrated on a complete blood count (CBC) if a ruptured cyst results in hemorrhage. While screening tests for ovarian malignancy are lacking, serum testing for CA 125 and other serum tumor marker panel tests can help guide decisions for referral to a gynecologic oncologist. CA 125 is nonspecific and can be elevated with various disease processes, including endometriosis, PID, or cirrhosis. Newer tumor marker panels include the multivariate index assay (MIA), which evaluates CA 125, prealbumin, apolipoprotein A-1, β2-microglobulin, and transferrin, or the Risk of Malignancy Algorithm (ROMA), which considers human epididymis protein 4, CA 125, and menopausal status.²⁴

Imaging

Transvaginal ultrasound (TVUS) is the preferred modality for imaging the adnexa and any adnexal masses or cysts. Most cysts have a classic ultrasound finding that can aid in identification. Hemorrhagic cysts have a fine reticular or netlike pattern. Endometriomas are characterized by homogeneous, low-level echoes in the absence of a solid component. Dermoid or mature teratomas are likely to contain hyperechoic nodules, fluid levels, and calcifications. Cyst rupture may lead to a collection of free fluid in the posterior cul-de-sac, but this finding is nonspecific, as women of reproductive age have been found to have physiologic-free fluid in the pelvis, independent of any pathologic process. Reassuring ultrasonographic characteristics associated with benign cysts include thin-walled, simple cysts and the absence of complex findings such as solid components, thick septations, or evidence of Doppler blood flow. Additional concerning ultrasound findings include ascites or a fixed mass. Abdominal computed tomography (CT) is utilized to identify metastases.

Treatment

Primary management for ovarian cysts is conservative. Even in the case of a ruptured hemorrhagic cyst, bleeding and pain are usually self-limited. Pain can be managed with nonsteroidal anti-inflammatory drugs (NSAIDs). However, if vital sign instability is noted or heavy or persistent blood loss is suspected, surgical management may be indicated.

Simple cysts are usually benign and can be closely observed with serial ultrasounds if they are < 10 cm. Many cysts, even those containing complex components, will resolve spontaneously; a study involving 6807 women with abnormal cysts were followed with ultrasound, and 63.2% of them resolved spontaneously.³ Another study found that 69.4% of postmenopausal women with unilocular cysts < 10 cm had spontaneous resolution, and no cases of cancer were diagnosed over a 6-year period of follow-up.⁴ While a definitive size cutoff has not been established, a cyst > 10 cm is typically treated with surgical removal.

In premenopausal patients, an ovarian cystectomy can be performed with care not to disrupt the blood supply to the ovary. In perimenopausal or postmenopausal patients, the risks and benefits of oophorectomy should be discussed. In addition, each patient’s individual risk of cancer should always be considered while making treatment decisions, and surgery by a gynecologist oncologist should be recommended if there is concern for a malignant process.

Outpatient Follow-up/Counseling

Patients with known ovarian cysts undergoing conservative management should be given torsion precautions. Cyst progression or resolution can be monitored with serial ultrasounds.

ADNEXAL TORSION

Definition

Adnexal torsion refers to the pathologic twisting of the ovary, fallopian tube, or both, causing partial or total occlusion of its blood supply.

Pathophysiology

Adnexal torsion can occur when the ovary, fallopian tube, or both become unbalanced around the axis created by the infundibulopelvic and utero-ovarian vessels. Although studies conflict on the diameter of ovaries most likely to cause torsion, and torsion may occur with either normal adnexa or adnexal mass, very small and very large ovaries are unlikely to torse. This is presumably because very small ovaries are relatively well balanced around their vascular axis, and very large ovaries lack the space needed to twist. However, torsion can and does occur in premenarchal girls, and the frequency of torsion occurring with normal adnexa is higher in this age group. Dermoid cysts may be more likely to unbalance the adnexa, probably because of the large difference in density between their primarily fatty content and normal ovarian tissue. Torsion of the right ovary is more common than of the left; the tendency for right-sided torsion is attributed to a longer right-sided utero-ovarian ligament and the prevention of torsion on the left due to the bulk of the sigmoid colon.

Evaluation

There is no set of diagnostic criteria that can accurately predict the presence or absence of torsion, and negative findings at the time of surgery for suspected torsion are common. However, there are risk factors that, if present, can raise the level of suspicion (Table 55-2). The history should include if a preceding activity led to onset of pain, as vigorous activity including intercourse can be the inciting event. Other risk factors include a history of cysts or torsion, polycystic ovarian syndrome (PCOS), ovarian stimulation, and pregnancy.

Symptoms

By far, the most consistent symptom caused by adnexal torsion is acute onset, unilateral pelvic pain. In the majority of cases, this pain is accompanied by nausea, and often by vomiting as well. Pain that is affected by position changes, such as lying down or leaning forward, is also suggestive.

Physical Exam Findings

Findings from physical examination are inconsistent. A significant minority of patients will have a low-grade fever. An enlarged, tender adnexa is suggestive, but pelvic exam findings range from completely normal to showing peritoneal signs.

Laboratory Findings

An important step in the laboratory evaluation of patients with the above described presentation is a pregnancy test to rule out ectopic pregnancy. Laboratory findings are otherwise typically normal, although mild leukocytosis is not uncommon.

Imaging

The cornerstone of evaluation for adnexal torsion is pelvic ultrasound with assessment of color Doppler flow to bilateral adnexa. This method classically shows an enlarged, heterogeneous, edematous ovary because the lymphatic drainage and venous flow are affected before arterial perfusion. The absence of flow has a high positive predictive value for torsion, but the converse is not true, as up to 60% of torsion patients have positive Doppler flow.⁵

Treatment

A patient who is suspected to have intermittent torsion that has resolved may be offered outpatient follow-up if she is clinically stable. Precautions should be given to the patient, and she should be instructed to seek immediate care if symptoms of torsion return.

Surgical treatment is required for suspected ovarian torsion, as viability of the ovarian tissue requires detorsion. A cystectomy should be performed concurrently, if applicable, because rates of recurrent torsion are high if the adnexa is simply detorsed or if the cyst is merely drained. Detorsion of black-and-bluish-appearing adnexa allows resumption of viable function in most cases, and salpingo-oophorectomy generally is not required. A study of 58 ischemic-appearing adnexa reported that 54 patients showed follicular ovarian development upon follow-up ultrasound.⁶ Ovarian necrosis can occur without detorsion, which results in reduced fertility and a nidus for infection. If the patient has a history of recurrent torsion, oopexy can be considered.

PELVIC INFLAMMATORY DISEASE

Definition

Pelvic inflammatory disease (PID) is a spectrum of conditions characterized by inflammation and infection of the upper female reproductive tract. Any combination of endometritis, salpingitis, tubo-ovarian abscess (TOA), and pelvic peritonitis may be present.

Epidemiology

The overall incidence of PID in the United States has decreased over the past decades. Data reported by the Centers for Disease Control and Prevention (CDC) from 2005 to 2014 demonstrates a decrease in PID of 71% among women aged 15 to 44 years in all geographic areas. Despite this decrease, PID still accounts for 51,000 outpatient visits per year and is the primary diagnosis in 6.4% of all inpatient gynecologic hospitalizations.⁷

Pathophysiology

The lower genital tract is home to a unique microbiological environment containing pathological and nonpathological bacteria coexisting in a constantly fluctuating balance. This nonsterile environment is separated from the sterile upper genital tract by the endocervical canal, which provides an architectural defense and contains cervical mucus, which is usually impermeable to ascending bacteria. Infection with sexually transmitted bacteria (most commonly Neisseria gonorrhoeae and Chlamydia trachomatis) can breach the standard defenses of the endocervical canal. The fall of this barrier allows entry to the upper genital tract by lower genital flora, resulting in varying combinations of endometritis, salpingitis, TOAs, and pelvic peritonitis. Therefore while PID is most commonly precipitated by one of these sexually transmitted pathogens, the upper-genital-tract infection itself is generally considered to be polymicrobial.

Evaluation

Because of the wide spectrum of symptomatology, from asymptomatic to septic, PID is notoriously difficult to characterize by diagnostic criteria. The CDC recommends against the use of diagnostic criteria; empiric treatment for PID is suggested for all women with abdominal or pelvic pain, and either cervical motion tenderness, uterine tenderness or adnexal tenderness without an other diagnostic explanation for their pain, and either cervical motion tenderness, uterine tenderness or adnexal tenderness.⁸

Risk factors for the development of PID include young age, multiple sex partners, history of prior PID or sexually transmitted infection, and history of sexually transmitted infection in a previous or current partner. Given the serious sequelae of infertility and chronic pelvic pain that can result from untreated PID, a low threshold for this diagnosis is necessary when evaluating a patient with pelvic pain, especially with the above risk factors. Box 55-2 lists the features associated with an increased likelihood of PID.