Hanna Richkind, Elaine Yu
A 37-year-old woman with a past medical history of anxiety, insomnia, chronic low back pain, and intermittent lower abdominal pain presented to the Emergency Department with several days of worsening lower abdominal and back pain. Her symptoms acutely worsened after eating a meal and were accompanied by nausea, vomiting, and diarrhea. Although the vomiting and diarrhea subsequently resolved, she continued to experience lower abdominal discomfort with pain radiating to the left flank and mid-back. At times, the severity of the discomfort caused her to crouch for relief. She denied a history of prior abdominal surgery.
Vital Signs: T 98.1 °F (36.7 °C), BP 129/88, HR 82, RR 16, SpO2 98% on room air.
Physical Exam:
Const: Well-appearing
Head: Atraumatic
Eyes: Normal Conjunctiva
ENT: Normal external ears, nose, and Mouth
Neck: Full range of motion. No meningismus
Resp: Clear to auscultation bilaterally, normal work of breathing
Cardio: Regular rate and rhythm, no murmurs
Abd: Soft, non-tender, non-distended. No guarding or rigidity. Normal bowel sounds
Skin: No petechiae or rashes
Back: No midline or flank tenderness
Ext: No cyanosis or edema
Neuro: Awake and alert. Moves all extremities
Psych: Normal Mood and Affect
Labs: Creatinine 0.70, BUN 5, Lipase 26, WBC 10.4, Hgb 11.1, MCV 77.2, MCH 23.9. Urinalysis with trace protein and 3+ blood, no bacteria and few squamous epithelial cells. Syphilis screen and human chorionic gonadotropin test were negative.
ED Course:
Labs largely unremarkable with no evidence of active infection. Upon further discussion, the patient reported that she had no difficulty with bowel movements or urination, but felt “heaviness” in her lower abdomen during and after urination.
Given the persistence of her abdominal discomfort and her report of lower abdominal pressure, point-of-care ultrasound (POCUS) was performed. Bedside transabdominal ultrasonography demonstrated a large complex cystic and solid pelvic mass measuring approximately 23 cm and extending toward the midline.
Formal pelvic ultrasonography further localized the 23 cm mass to the right adnexa and confirmed a separate heterogenous 4cm left adnexal mass. Doppler imaging demonstrated preserved blood flow.
Discussion:
The differential diagnosis of lower abdominal and pelvic pain in a reproductive-age woman is broad and includes gastrointestinal, genitourinary, and gynecologic etiologies. Before POCUS, considerations in this patient included gastroenteritis, appendicitis, urinary tract infection, nephrolithiasis, ovarian cyst, uterine leiomyoma, ovarian torsion, ectopic pregnancy, and tubo-ovarian abscess.
The patient’s initial symptoms were compatible with an acute gastrointestinal illness. She developed nausea, vomiting, and diarrhea after eating a meal, and these symptoms subsequently resolved. However, persistence of lower abdominal and back pain after resolution of her gastrointestinal symptoms warranted reconsideration of the initial differential and evaluation for a structural cause of her symptoms (1). Furthermore, nausea and vomiting are nonspecific findings that may also occur in patients with symptomatic adnexal masses and ovarian torsion (2).
An important feature of this case was the relatively benign physical examination despite the presence of a 23 cm adnexal mass. The patient's abdomen remained soft, non-tender, and non-distended, and she had no appreciable flank or back tenderness. Although physical examination remains an important component of the evaluation of pelvic pain, examination alone may fail to identify significant adnexal pathology. Prior studies have demonstrated limited sensitivity of pelvic and bimanual examinations for the detection of adnexal masses (3). Accordingly, a reassuring examination should not preclude imaging when symptoms remain unexplained.
The patient’s description of lower abdominal “heaviness” during and after urination provided an additional clue suggesting a pelvic structural abnormality. Pelvic and adnexal masses may produce urinary pressure, frequency, urgency, or other lower urinary tract symptoms through mass effect on the bladder and surrounding structures (4). In this case, the urinary complaint prompted bedside imaging despite otherwise nonspecific symptoms and a reassuring abdominal examination.
Ovarian torsion remained an important diagnostic consideration given the presence of bilateral adnexal lesions. Adnexal masses increase the risk of torsion, particularly when greater than 5 cm in diameter, and mature cystic teratomas are recognized lead points for torsion (4). Although Doppler ultrasonography demonstrated preserved blood flow, normal arterial flow does not exclude ovarian torsion because of the dual blood supply to the ovary and the possibility of intermittent or incomplete torsion (2,4). Torsion was considered less likely in this patient given the subacute course, absence of persistent acute severe pain, improvement in nausea and vomiting, and overall clinical presentation.
Imaging plays a central role in the evaluation of acute pelvic pain. Transabdominal and transvaginal ultrasonography are generally the preferred initial imaging modalities when a gynecologic etiology is suspected. CT is commonly obtained when gastrointestinal or urinary pathology remains in the differential and may also identify previously unsuspected gynecologic abnormalities (6).
In this patient, POCUS rapidly redirected the diagnostic evaluation from common gastrointestinal and urinary causes of abdominal pain toward a previously unsuspected pelvic mass. The bedside examination identified significant pathology despite nonspecific symptoms, largely unremarkable laboratory testing, and a benign abdominal examination, prompting definitive cross-sectional and formal pelvic imaging.
Conclusion:
This case demonstrates the potential value of point-of-care ultrasound in patients with persistent abdominal or pelvic symptoms despite an initially reassuring examination and laboratory evaluation. A subtle complaint of urinary pressure prompted bedside ultrasonography that rapidly identified a large, previously unsuspected adnexal mass and redirected the diagnostic evaluation toward a gynecologic etiology. POCUS may therefore serve as a useful adjunct in the evaluation of undifferentiated abdominal and pelvic pain when the clinical presentation remains unexplained.
References:
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- Adnexal Torsion in Adolescents: ACOG Committee Opinion No, 783 (2019). Obstetrics & Gynecology, 134(2), e56-e63. https://doi.org/10.1097/AOG.0000000000003373
- Biggs WS, Marks ST. Diagnosis and Management of Adnexal Masses. Am Fam Physician. 2016 Apr 15;93(8):676-81. PMID: 27175840.
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- Bonney R, Revels JW, Wang SS, Lussier R, Dey CB, Katz DS, Moshiri M. A comprehensive radiologic review of abdominal and pelvic torsions. Abdom Radiol (NY). 2021 Jun;46(6):2942-2960. doi: 10.1007/s00261-020-02868-x. Epub 2021 Jan 2. PMID: 33388807.
- Expert Panel on GYN and OB Imaging; Brook OR, Dadour JR, Robbins JB, Wasnik AP, Akin EA, Borloz MP, Dawkins AA, Feldman MK, Jones LP, Learman LA, Melamud K, Patel-Lippmann KK, Saphier CJ, Shampain K, Uyeda JW, VanBuren W, Kang SK. ACR Appropriateness Criteria® Acute Pelvic Pain in the Reproductive Age Group: 2023 Update. J Am Coll Radiol. 2024 Jun;21(6S):S3-S20. doi: 10.1016/j.jacr.2024.02.014. PMID: 38823952.
