Predicting teratoma in the retroperitoneum in men undergoing post-chemotherapy retroperitoneal lymph node dissection

Purpose: The biological potential of teratoma remains unpredictable, therefore identifying its presence in the retroperitoneum remains important. We evaluated patients undergoing post-chemotherapy retroperitoneal lymph node dissection for nonseminomatous germ cell tumors to determine predictors of teratomatous elements in the retroperitoneum. Materials and Methods: We identified 532 patients from 1989 to 2003 who underwent retroperitoneal lymph node dissection following chemotherapy for nonseminomatous germ cell tumors at our institution. Multiple clinical and pathological variables were reviewed from our prospective retroperitoneal lymph node dissection database. A logistic regression model was designed based on preoperative variables to predict the presence of teratomatous elements in the retroperitoneal lymph node dissection specimen. Results: Of the 532 patients in our series 450 (85%) received only induction chemotherapy and 82 (15%) required salvage chemotherapy. Teratomatous elements were identified in the orchiectomy specimen in 42% of patients. Retroperitoneal nodal pathology revealed teratomatous elements in 235 (44%) patients and only teratoma in 210 (40%) patients. By multivariate analysis testicular yolk sac tumor (p = 0.046), teratoma in the orchiectomy specimen (p < 0.005), relative change in nodal size before and after chemotherapy (p < 0.005), and no requirement for salvage chemotherapy (p = 0.03) were independent predictors for the presence of teratoma in the retroperitoneum. Conclusions: Teratoma remains a common histological finding in the retroperitoneal lymph nodes following chemotherapy. We have identified several pre-retroperitoneal lymph node dissection variables that predict the finding of teratoma in the retroperitoneum for men treated with chemotherapy for metastatic nonseminomatous germ cell tumors.