Clinical stage I mature teratoma of the testis--retroperitoneal lymphadenectomy or surveillance?

Abstract

Pure teratomas are considered to be less aggressive and less likely to metastasize than other nonseminomatous germ cell tumors. Therefore, patients with mature teratomas are considered to be candidates for surveillance protocols. We report on the clinical history and treatment of 44 patients with a primary pure testicular teratoma. In all, 35 patients (79.5%) presented with clinically low-stage disease [n = 26, clinical stage I (59.1%); n = 9, clinical stage IIA/B (20.4%)] and underwent radical orchiectomy followed by retroperitoneal lymphadenectomy (RPLND); nine patients (20.5%) presented with clinically advanced disease (clinical stage IIC to stage IV). Archival tumor blocks were available for pathological reevaluation and serial sections were obtained in all cases. The frequency of lymph node metastases in patients with clinical stage I disease was 19.2%; in patients with clinical stage IIA/B the risk was 66%. Pathohistological diagnosis of mature teratoma was confirmed in all cases; however, 17/20 patients demonstrated scars or calcifications in the adjacent parenchyma, indicating a burned-out tumor and 3/20 demonstrated microfocal germ cell tumor elements. None of the clinical stage I patients relapsed during follow-up; relapse rate among patients with stage IIA/B disease was 33%. Our data demonstrate the malignant potential of pure testicular mature teratoma. Based on our results, metastases in testicular mature teratoma seem to result from metastazising non-germ-cell components undergoing early regression as demonstrated by the high frequency of burnedout tumors. We recommend serial sections of the orchiectomy specimen in all cases of pure mature teratoma for deciding on adequate management: RPLND in cases with associated scars, calcifications or microfocal malignant germ cell components, and surveillance in cases with pure mature teratomas.