The Role of Endoscopic Ultrasonography in the Diagnosis of Retroperitoneal Lymphatic Malformations

Summary

This article explores the value of endoscopic ultrasound (EUS) in diagnosing retroperitoneal lymphatic malformation and proposes its imaging criteria.

Abstract

Lymphatic malformation (LM), formerly known as lymphatic cyst, is an extremely rare condition with no specific symptoms, often incidentally detected during examinations for other diseases and confirmed by postoperative pathology. Endoscopic ultrasound (EUS), a non-invasive tool, plays a critical role in diagnosing LM and reducing unnecessary surgeries. We report the case of a young male with 4-day upper abdominal pain was admitted. Imaging (chest CT, enhanced upper abdominal CT, MRI+MRCP) revealed a cystic lesion in the pancreatic head connected to a tubular structure. EUS further showed the lesion was linked to an enlarged lymph node, leading to a diagnosis of retroperitoneal LM, later confirmed by pathology. EUS facilitates early diagnosis by visualizing ductal continuity, avoiding unnecessary interventions like biopsy or surgery.

Introduction

Lymphatic malformation (LM) is a congenital vascular anomaly characterized by dilated, aberrant lymphatic channels. Historically and inaccurately termed "lymphangioma," it is now recognized as a malformation of lymphatic development rather than a true neoplasm, a critical reclassification formalized within the International Society for the Study of Vascular Anomalies (ISSVA) framework¹. While LMs can occur throughout the body, retroperitoneal localization is exceptionally rare, accounting for less than 1% of all cases². The diagnosis of deep-seated lesions in this anatomically complex region is challenging, with ....

Protocol

This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the Yueyang Central Hospital. Written informed consent was obtained from the patient. The consumables and the equipment used are listed in the Table of Materials.

1. Equipment and patient preparation

1. Equipment
   1. Echoendoscope: A linear array echoendoscope was used for real-time ultrasound imaging.
      NOTE: FNA was not performed in this case.
   2. Ultrasound processor: A compatible ultrasound processing system was used.
   3. Imaging parameters: The ultrasound ....

Results

Pathological examination revealed a well-circumscribed cystic mass characterized by prominent smooth muscle hyperplasia within the cyst wall, along with areas of mucinous degeneration. Dense lymphoid hyperplasia with reactive follicle formation was also observed, supporting the lymphatic origin of the lesion (Figure 4A). No significant cytologic atypia or malignant features were identified in the examined sections.

Immunohistochemical analysis further confirmed th.......

Discussion

Lymphatic malformations (LMs) are rare benign cystic lesions, with retroperitoneal cases constituting less than 1% of all occurrences¹. Conventional imaging modalities (ultrasound, CT, MRI) can characterize cystic properties but cannot definitively distinguish LM from other cystic masses, often necessitating pathological confirmation^8,9. This article details a focused endoscopic ultrasound (EUS) protocol for evaluating suspected retroperit.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Built-in imaging software	Fujifilm	https://www.fujifilm.com/in/en/healthcare/endoscopy/endoscopy-ultrasonography/endoscopic-ultrasonography-system
Linear array echoendoscope	Fujifilm	EG-5800UT	"For real-time ultrasound imaging of retroperitoneal lesions"
Ultrasound processing system	Fujifilm	9000	"Compatible processor for echoendoscope; provides B-mode