[The differential projection index as a sign of metastases in lymph nodes (author's transl)]

Five hundred and fourty-four lymph nodes seen in 107 lymphograms were examined at operation and histologically. According to our findings the differential projection index (Px) of Wiljasalo has a high degree of accuracy. The index is calculated from the maximal (a) and minimal (b) diameter of the node in various projections, expressed as a percentage formula: see text. Even considering technical sources of error, such as varying degrees of magnification of lymph nodes on oblique projections, the accuracy of the index is very high at 80%. It can be considered as the most accurate sign of metastases during lymphography.