Authors Mariana Quintanar-Martinez, Maria del Carmen Manzano-Robleda, Enrique Murcio-Pérez, Gustavo López-Arce, Isaac Bartnicki-Navarrete, Luis Uscanga, Angélica Hernández-Guerrero, Jorge López-Cossio, Alvaro Villalobos-Garita, Jorge Perales-Oliva, José Vargas-Jimenez, Félix Téllez-Avila. Abstract

Background Malignant etiologies are found in 70-80% of symptomatic retroperitoneal masses. Histology is required for diagnosis and treatment. Information about endoscopic ultrasound (EUS)-guided tissue acquisition (EUS-GTA) is scant for retroperitoneal masses. This study aimed to assess the pathology results of EUS-GTA for diagnosing retroperitoneal masses.

Methods This retrospective, multicenter study involved patients from 5 care centers. All patients with retroperitoneal masses who underwent EUS evaluation were enrolled. We recorded demographic and clinical characteristics, location and size of the mass, type of needle (FNA/FNB), and complications related to the procedure.

Results A total of 43 patients were included. The median age was 50.5 (range: 23-83) years, and 22 (51.2%) were female. The initial symptom was abdominal pain in 23 (52.3%) cases and weight loss in 11 (25%). Initial imaging was by computed tomography in 33 (75%) patients. Diagnosis with EUS-GTA was reached in 67.5% (29/43) cases. The most frequent histological diagnosis was carcinoma, in 25.5% (11/43). A malignant etiology was found in 31 (72%): 20 were primary tumors from the retroperitoneum, and 11 were metastases. In patients with metastasis, surgery was avoided and medical treatment was indicated. No adverse events were reported.

Conclusion EUS and EUS-GTA can frequently provide accurate tissue diagnosis and significantly impact the subsequent management.

Keywords Endoscopic ultrasound, retroperitoneal mass, fine-needle aspiration, fine-needle biopsy

Ann Gastroenterol 2024; 37 (1): 104-108