title: Teratoma in the orchiectomy specimen and volume of metastasis are predictors of retroperitoneal teratoma in post-chemotherapy nonseminomatous testis cancer.
abstract: OBJECTIVE
  Patients who require post-chemotherapy retroperitoneal lymph node dissection after induction chemotherapy for metastatic testis cancer derive therapeutic benefit from resection of teratoma but resection of necrosis is not beneficial. We determine if the absence of teratoma in the orchiectomy specimen is a reliable predictor of the absence of teratoma in the retroperitoneum at post-chemotherapy retroperitoneal lymph node dissection.
  
  
  METHODS
  A retrospective review of the Indiana University testis cancer data base was performed. A total of 644 patients who underwent retroperitoneal lymph node dissection after induction chemotherapy only were selected for study. The presence or absence of teratoma in the orchiectomy specimen and volume of retroperitoneal tumor were analyzed as predictors of retroperitoneal teratoma at post-chemotherapy retroperitoneal lymph node dissection.
  
  
  RESULTS
  Of the patients with teratoma in the orchiectomy specimen 85.6% had an element of teratoma in the retroperitoneum, and of those without teratomatous elements in the orchiectomy specimen 48% had teratoma in the retroperitoneum (p <0.00001). Increasing volumes of retroperitoneal tumor were associated with a higher probability of discovering teratoma at post-chemotherapy retroperitoneal lymph node dissection.
  
  
  CONCLUSIONS
  The absence of teratoma in the orchiectomy specimen does not reliably predict the absence of teratoma in the surgical specimen at post-chemotherapy retroperitoneal lymph node dissection. Post-chemotherapy surgery is indicated if retroperitoneal tumor remains after chemotherapy irrespective of the presence or absence of teratoma in the orchiectomy specimen.
mesh_terms: D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D009367:Neoplasm Staging; D009919:Orchiectomy; D011237:Predictive Value of Tests; D011379:Prognosis; D012186:Retroperitoneal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D013724:Teratoma / Q000188:drug therapy / Q000473:pathology / Q000556:secondary* / Q000601:surgery; D013736:Testicular Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000601:surgery*; D013737:Testis / Q000473:pathology*