Rationale and objectives: The authors assess the value of combining high-resolution ultrasonography (HRUS) findings in a scoring scale for distinguishing malignant from reactive lymphadenopathy and explain the pathologic causes of altered nodal sonographic architecture.
Materials and methods: Sixty-one nodes obtained from 32 consecutive patients were prospectively scanned with 7.5-MHz ultrasound probes in a waterbath. Three sonographic features--long-to-short axis ratio (L/S), hilar width, and cortical width--were graded on a 5-level scoring scale (0-4). Nodes scored > or = 3 were considered malignant and < or = 2 benign. Subsequently, all nodes were microsectioned in a plane matching the sonograms, allowing direct sonographic-pathologic correlation.
Results: Eighty-two percent of nodes were correctly characterized using the above cut-off point (sensitivity: 87%, specificity: 74%). Eighty-three percent of nodes scored 4 were malignant and 95% scored 0 were benign. Eighty-two percent of nodes with L/S < 2, 81% with no hilus, and 70% with eccentric cortical widening were malignant, whereas 72% with L/S > or = 2, 86% with a wide hilus, and 91% with a narrow cortex were benign. Sonographic-pathologic correlation showed that tumor infiltration results in rounded nodal shape, loss of hilar echogenicity and cortical widening, whereas reactive disease tends to preserve nodal architecture.
Conclusion: Morphologic changes detectable using HRUS help distinguish benign from malignant lymph nodes.