Correlation between retroperitoneal lymph node size and presence of metastases in nonseminomatous germ cell tumors

Eighty-five patients had staging laparoscopic retroperitoneal lymph node dissection (L-RPLND) for nonseminomatous germ cell tumors at our institution. The largest lymph node size was measured and presence or absence of metastatic disease was determined. A total of 1139 lymph nodes have been removed and in 27 (31.8%) patients, metastases in one or more lymph nodes were detected. There were 338 (29.7%) hilar, 259 (22.7%) paraaortic, 221 (19.4%) interaortocaval, 171 (15%) paracaval, 133 (11.7%) preaortic and 17 (1.5%) precaval lymph nodes. The total number of lymph nodes with metastases was 74 (6.5%), and 1065 (93.5%) nodes did not have any metastases. The average size of a lymph node with metastases was 1.05 (0.3-3), and without metastases it was 0.55 (0.1-2.5) cm, (p<0.001). If we use > 1 cm size of a lymph node as a "cut-off" value for enlargement and presence of metastases, 60% of metastatic lymph nodes would be missed since they were all ≤ 1 cm. Our results have shown that decreasing size of lymph nodes which are considered positive from > 1 cm to 0.7 -0.8 cm can be recommended, with specificity and sensitivity equal 70%.