Case Report
To Drain or not to Drain? Point-of-care Ultrasound to Investigate an Axillary Mass: Case Report Kishan Patel, BS* Zara Khan, MD† John Costumbrado, MD†
*University of California, Riverside School of Medicine, Riverside, California † Riverside Community Hospital/University of California, Riverside, Department of Emergency Medicine, Riverside, California
Section Editor: Rachel Lindor, MD, JD Submission History: Submitted May 23, 2021; Revision received February 2, 2022; Accepted February 4, 2022 Electronically published April 18, 2022 Full text available through open access at http://escholarship.org/uc/uciem_cpcem DOI: 10.5811/cpcem.2022.2.53357
Introduction: Point-of-care ultrasound (POCUS) has great sensitivity in the diagnosis of abscesses and swollen lymph nodes. Many studies outline the characteristics that distinguish abscesses from lymph nodes on POCUS. Case Report: We present a case from the emergency department in which a patient presented with a potential abscess but was found to have a malignant lymph node on imaging. Conclusion: Point-of-care ultrasound can be used to differentiate an abscess from a swollen lymph node. Abscesses are generally anechoic or hypoechoic with septae, sediment or gas contents, and they lack internal vascularity. Benign lymph nodes are echogenic with hypoechoic cortex with hilar vascularity. [Clin Pract Cases Emerg Med. 2022;6(2):155–158.] Keywords: point-of-care ultrasound; POCUS; abscess; lymph node; case report.
INTRODUCTION Evaluation of abscesses versus enlarged lymph nodes is an important distinction to be made in the emergency department (ED) prior to performing incision and drainage in a patient who presents with a “lump.” Point-of-care ultrasound (POCUS) is a diagnostic tool that has been shown to have a greater sensitivity than physical exam alone to diagnose both abscesses and enlarged lymph nodes in the ED.1,2,3,4,5 Previous ED studies have shown that POCUS can allow clinicians to diagnose abscesses with significant accuracy and speed, often changing medical management as a result.6,7 Previous studies have also characterized distinctive qualities of abscesses and lymph nodes that can be used to confirm the presence of one as opposed to the other.4,5,7,8,9,10,11 From experiences in the ED with patient presentations requiring accurate identification of an abscess against a lymph node, we recognized that POCUS can play an instrumental role in the rapid detection and distinction between the two. The echogenicity of abscess on sonography varies based on the characteristics of the abscess itself. However, a common distinguishing factor for all abscesses is the absence Article in Press
of internal vascularity.3,12 Lymph nodes, on the other hand, typically display significant hilar vascularity, with malignant nodes having mixed or absent hilar vascularization.4,8 However, unlike the varied echogenicity of an abscess, lymph nodes are frequently small, oval, and hypoechoic in appearance.4,5 With an understanding of the common characteristics and qualities of both abscesses and lymph nodes, benign or metastatic, we believe POCUS can be used in conjunction with a thorough physical exam to guide medical management. We present a case in the ED where a patient presented with signs and symptoms of an abscess but instead was confirmed to have an enlarged lymph node, raising suspicion for underlying metastatic disease. CASE REPORT A 54-year-old female with a past medical history of kidney transplantation, hypertension, and mitral valve replacement presented to the ED for two days with a painful lump in her left axilla. She was seen at urgent care two days prior and prescribed oral clindamycin. The lump did not change in size after the antibiotic; she denied fevers or
155
Clinical Practice and Cases in Emergency Medicine
