Clinical Impact of Endoscopic Ultrasound-Guided Fine Needle Aspiration Biopsy In the Diagnosis of Patients with Lymphoma Who Have No Superficial Lymphadenopathies
Authors: Goto Naoe , Yasuda Ichiro , Tsurumi Hisashi , Doi Shinpei , Hara Takeshi , Iwashita Takuji , Kasahara Senji , Nakashima Masanori , Kanemura Nobuhiro , Adachi Seiji , Yamauchi Takahiro , Takami Tsuyoshi , Moriwaki Hisataka 
Published: October 2019

Abstract
Abstract 5083

Background:
In patients with mediastinal and intra-abdominal lymphoma who do not have superficial lymphadenopathies, the diagnosis is usually made by surgical sampling with open thoracic surgery, laparotomy, mediastinoscopy, thoracoscopy, or laparoscopy. However, these surgical procedures are cumbersome and invasive; therefore, the treatment is often delayed, and doctors often hesitate to attempt the procedures for patients in poor performance status (PS). Recently, endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been used for the diagnosis of unknown mediastinal and abdominal lymphadenopathies or masses. With this procedure, pathological materials can be obtained through the gastrointestinal tract under real-time ultrasound imaging guidance. It is regarded as a minimally invasive, safe, and relatively accurate procedure. However, only a small amount of material can be sampled with this technique. Immunohistochemical, flow cytometric, and chromosomal analyses are essential for the diagnosis of lymphoma, but it is not clear whether these analyses can be assessed on samples obtained by EUS-FNA.

Aim:
To evaluate the yield of EUS-FNA for the diagnosis of lymphoma.

Patients and Methods:
Between June 2005 and December 2009, a total of 224 consecutive patients who were suspected to have lymphoma underwent EUS-FNA with a 19-gauge needle at our hospital. We reviewed the baseline characteristics of the patients; the histological diagnosis including immunohistochemical stainings, flow cytometric analysis (FCM), and chromosomal analysis (by the G-banding method) of the FNA samples; and the final diagnosis. EUS-FNA was performed in 241 lesions in the 224 patients. One hundred and forty-three patients (63.8%) underwent the procedure as outpatients. Ten in 224 patients had a poor PS (grade 4).

Results:
The locations of the lesions were mediastinal in 99 and intra-abdominal in 142 (inclusive of 9 splenic, 5 left adrenal, 2 pancreatic, and 1 right renal lesions). After all, 142 in 224 patients were finally diagnosed as having lymphoma. Among them, 138 in 142 patients (97.2%) were diagnosed by EUS-FNA, and detailed classification in accordance with the WHO system was also possible in 125 in 142 patients (88.0%) on the basis of comprehensive findings including immunohistochemical staining, FCM, FISH method, and chromosomal analysis. While, remaining 82 in 224 patients were diagnosed as having inflammatory diseases such as sarcoidosis, necrotizing lymphadenitis, tuberculosis, or other cancers. No serious complications occurred with the procedure.

Conclusions:
EUS-FNA is a safe and convenient procedure with high diagnostic value for the diagnosis of lymphoma. Therefore, this procedure should be initially considered to attempt for patients with mediastinal and intra-abdomnal lymphadenopathy or mass who do have no superficial lesions.

Disclosures:
No relevant conflicts of interest to declare.