Can we predict the presence of teratoma in the retroperitoneum before post-chemotherapy retroperitoneal lymphadenectomy?

Abstract

The biological potential of teratoma remains unpredictable, therefore identifying its presence in the retroperitoneum remains important. We evaluated patients undergoing post-chemothe rapy retroperitoneal lymphadenectomy (PC-RPLA) for nonseminomatous testicular tumors (NSTT), to determine predictors of teratomatous elements in the retroperitoneum. We identified 161 patients from 1982 to 2005 who underwent PC-RPLA for metastatic NSTT. Multiple clinical and pathological variables were reviewed from out RPLA database. Of the 161 patients in our series, 112 (70%) received only induction chemotherapy and 49 (30%) required 2nd line chemotherapy. Studies of retroperitoneal pathology demonstrated the presence of fibrosis in 44 (27%), teratoma in 82 (51%) and vital carcinoma in 35(22%).Among 82 patients (51%) with finding of teratomatous elements at PC-RPLA, we revealed the presence ofmature teratoma in 85%, immature teratoma in 12% and teratoma with malignant transformation in 3%. Of the 99 patients (61%) with teratomatous elements in the primary NSTT, 61 (62%) had teratoma at PC-RPLA. Even in the absence of teratoma in the primary NSTT, teratoma was present in the retroperitoneum in 21 of 62 patients (32%)(p<0.0001). All patients had normal values of serum tumor markers (STM) at PC-RPLA. Post-chemotherapy retroperitoneal residual mass measuring <2 cm, from 2.1-5.0 cm and > 5 cm in diameter occured in 30%, 52% and 55%, respectively. By multivariate analysis , teratoma in the orchiectomy specimen (p<0.005), relative change in nodal size before and after chemotherapy (p<0.005), and no requirement for 2nd line chemotherapy (p=0.33) were independent predictors for the presence of the teratoma in the retroperitoneum. Teratoma remains