[Abdominal lymph nodes: the echographic evaluation criteria].

US patterns of abdominal lymph nodes were investigated in patients with neoplastic and non-neoplastic diseases, and in randomly-chosen subjects with no evidence of any pathologic condition. Major longitudinal diameter (DMax) was statistically evaluated, together with minor transverse diameter (DMin), roundness index (RI), and structural index (IS)-i.e., the presence of a central hyperechoic line (as the US sign of normal lymph node architecture). DMax proved to be useless for distinguishing between groups. The presence of a central hyperechoic line was the most useful parameter, although the extant 3 (DMin, RI, IS) were also useful for distinguishing between groups. By correlating each numerical parameter with the hyperechoic line sign an even better discrimination was obtained. Thus, it can be assumed that only a combined and comprehensive evaluation of the above parameters makes the best criterion to differentiate between neoplastic and non-neoplastic abdominal lymph nodes.