Usefulness of contrast-enhanced endoscopic ultrasonography in the differentiation between malignant and benign lymphadenopathy.
OBJECTIVE
Endoscopic ultrasonography (EUS) is considered the most useful diagnostic modality for regional staging; however, it is still difficult to diagnose lymph node metastasis by EUS images only. In this study, we report the usefulness of contrast-enhanced EUS (CE-EUS) in the evaluation of benign lymph nodes (BLN) or malignant lymph nodes (MLN) based on blood flow patterns.


METHODS
In the retrospective study, CE-EUS was performed in 46 patients in whom EUS revealed lymph node in the mediastinum or abdominal cavity. The subjects consisted of 22 patients with BLN and 24 patients with MLN. The lesions were examined by EUS, and the maximal and minimal diameters of lymph nodes were measured. Thereafter, the shape and internal echoes were investigated, and the findings were morphologically classified based on Catalano's report. Enhancement effects and the diagnostic capability of CE-EUS were evaluated. In the prospective study, BLNs were differentiated from MLN using the enhancement patterns on CE-EUS based on the results of the retrospective study, and the diagnostic capability was evaluated.


RESULTS
In the retrospective study, there were no significant differences in the maximal diameter and maximal/minimal diameter ratio between MLN and BLN. The morphology was classified into four types. Based on the morphological classification, the sensitivity, specificity, and accuracy rate were 88.2%, 77.3%, and 82.1%, respectively. On CE-EUS, the enhancement pattern was classified into three types. The BLN lesions showed uniform enhancement (19/22). In all patients with MLN, a defect of enhancement was observed (24/24). The sensitivity, specificity, and accuracy rate of CE-EUS were 100%, 86.4%, and 92.3%, respectively. In the prospective study, the sensitivity, specificity, and accuracy rate of CE-EUS were 100%, 81.8%, and 92.0%, respectively.


CONCLUSIONS
CE-EUS is useful for differentiating BLN from MLN.
Kanamori
Akira
A
Department of Gastroenterology, Nagoya University School of Medicine, Nagoya, Japan.
Hirooka
Yoshiki
Y
Itoh
Akihiro
A
Hashimoto
Senju
S
Kawashima
Hiroki
H
Hara
Kazuo
K
Uchida
Hiroki
H
Goto
Jun
J
Ohmiya
Naoki
N
Niwa
Yasumasa
Y
Goto
Hidemi
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D003287:Contrast Media; D003937:Diagnosis, Differential; D004067:Digestive System Neoplasms / Q000473:pathology*; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007150:Immunohistochemistry; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018615:Ultrasonography, Doppler, Color
D003287:Contrast Media