To evaluate, in detail, the histopathologic features of metastatic testicular germ cell tumors to retroperitoneal lymph nodes treated with primary retroperitoneal lymph node dissection (RPLND) and correlate the findings with patients' outcomes.

We studied 183 patients with documented pathologic stage II disease with or without elevated serum tumor markers, selected from 453 patients who underwent primary RPLND at our institution from 1989 to 2002. Tumor type(s), size and extent of disease, and amount of tumor necrosis were assessed and correlated with outcome.

Embryonal carcinoma was the most common tumor type, present as the only component in 99 cases (54%) and the predominant tumor type (>50%) in 142 (78%). The number of positive lymph nodes ranged from 1 to 40 from a total of 2-80 lymph nodes examined (median, 28). Extranodal extension (ENE) was identified in 120 cases (66%). Among 73 patients followed up expectantly and with normal serum tumor markers, 19 experienced relapse, the probability of which was higher in patients with more positive nodes, larger metastases, and presence of ENE. However, none of these differences was statistically significant (all P >.2). The predominance of embryonal carcinoma and the presence of tumor necrosis were not significantly associated with outcome.

In this cohort, most patients treated with primary RPLND and with positive lymph nodes also had ENE. We did not identify any variables to be significantly associated with relapse after RPLND in patients managed expectantly. Additional studies with more patients are needed to validate our findings.