title: Incidence and clinical outcome of patients with teratoma in the retroperitoneum following primary retroperitoneal lymph node dissection for clinical stages I and IIA nonseminomatous germ cell tumors.
abstract: OBJECTIVE
  We determined the incidence and clinical outcome of patients with clinical stages I and IIA nonseminomatous germ cell tumors (NSGCT), and teratoma in the retroperitoneum following primary retroperitoneal lymph node dissection (RPLND).
  
  
  METHODS
  Between January 1989 and February 1998, 294 patients with clinical stages I (209) and IIA (85) underwent primary RPLND at our institution. The primary tumor had teratomatous elements in 179 (61%) cases. Median followup was 27.8 months.
  
  
  RESULTS
  The overall incidence of teratoma in the retroperitoneum was 9% (25 of 294), and 21% (25 of 118) in patients with pathological stage II disease. The incidence of teratoma in the retroperitoneum increased from 3% (6 of 209) in clinical stage I to 22% (19 of 85, chi-square test p <0.0001) in clinical stage IIA. The incidence of teratoma in patients with pN1/N2/N3 disease increased from 9% (6 of 64) in clinical stage I to 35% (19 of 54) in clinical stage IIA (chi-square test p = 0.0006). All 25 patients with pathological stage II and teratoma in the retroperitoneum have no evidence of disease.
  
  
  CONCLUSIONS
  The incidence of teratoma in the retroperitoneum increases with clinical and pathological stage. Teratomatous elements in the orchiectomy specimen predict teratoma in clinical and pathological stage II NSGCT. The absence of teratoma in the primary tumor does not preclude its presence in the retroperitoneum. Primary RPLND avoids the persistence of chemoresistant teratoma in the retroperitoneum, contributes to the high cure rate of patients with low stage NSGCT and decreases the potential for late relapse.
mesh_terms: D005500:Follow-Up Studies; D018237:Germinoma / Q000453:epidemiology* / Q000556:secondary / Q000601:surgery*; D006801:Humans; D015994:Incidence; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D009367:Neoplasm Staging; D011446:Prospective Studies; D012186:Retroperitoneal Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery*; D012187:Retroperitoneal Space; D012189:Retrospective Studies; D013724:Teratoma / Q000453:epidemiology* / Q000556:secondary / Q000601:surgery*; D013736:Testicular Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery*