ROLE OF SONOELASTOGRAPHY IN DIFFERENTIATING BENIGN FROM MALIGNANT CERVICAL LYMPH NODES AND CORRELATING WITH PATHOLOGY

Abstract

Background: Cervical lymphadenopathy can be secondary to numerous etiologies. Combined use of ultrasonography and elastography improves diagnostic efficacy in differentiating benign from malignant cervical lymph nodes, thereby helping in treatment planning and reducing unnecessary fine needle aspiration cytology/ biopsy. Aims and Objectives: To perform B-mode ultrasonography, color Doppler imaging and elastography of the cervical lymph nodes, to correlate B-mode ultrasonography, color Doppler imaging, and elastography findings with pathological findings and to calculate sensitivity, specificity and diagnostic accuracy of ultrasonography and elastography. Material and Methods: A prospective observational study was conducted over a period of eighteen months on 78 patients with clinically enlarged cervical lymph nodes who were referred to our department for ultrasonography. Patients first underwent ultrasonography (B-mode and color Doppler imaging) followed by elastography. Lymph node morphology on B-mode was assessed based on short axis diameter, short-to-long axis ratio, fatty hilum, echogenicity and margin. Vascularity of lymph node on colour Doppler imaging was divided into three patterns. On elastography, lymph nodes were defined based on elastography pattern and strain index. XV Results: Out of 78 cases, there were total of 43 females and 35 males. There was no significant difference between gender distribution among benign and malignant cervical lymph nodes. Among all ultrasonography parameters, fatty hilum was found to have highest diagnostic accuracy (73%), followed by vascularity pattern (70%). Combined use of all ultrasonography parameters yielded better sensitivity (90%), specificity (88%) and diagnostic accuracy (89%) than individual parameters. Five scale elastography pattern had 83% sensitivity, 97% specificity and 89% diagnostic accuracy. In the current study, use of strain index cut-off of 2 showed sensitivity of 93%, specificity of 96% and diagnostic accuracy of 94%. Elastography pattern and strain index together had sensitivity of 93%, specificity of 94% and diagnostic accuracy of 94%. Together ultrasonography and elastography achieved sensitivity of 96%, specificity of 94% and diagnostic accuracy of 95%. Conclusion: Elastography can be a useful adjunct to ultrasonography and plays a major role in accurate diagnosis of cervical lymphadenopathy. Elastography pattern and cut-off strain index of 2 can effectively differentiate benign from malignant cervical lymph nodes.