The role of retroperitoneal lymphadenectomy in mature teratoma of the testis.

PURPOSE

Pure testicular teratoma is rare in adulthood with an incidence of 5%. Pure teratoma is considered less aggressive and less likely to metastasize than other nonseminomatous germ cell tumors. Therefore, patients with mature teratoma have been considered candidates for surveillance protocols. We report our experience with 44 cases of primary pure testicular teratoma.

MATERIALS AND METHODS

We retrospectively identified 44 patients (5.7%) with primary pure teratoma of the testis of the 772 treated for testicular germ cell tumors at our institutions. Archival tumor blocks were available for pathological reevaluation and serial sections were obtained in all cases. A total of 35 patients (79.5%) who presented with clinical low stage disease, including stage I in 26 (59.1%) and stage IIA/B in 9 (20.4%), underwent radical orchiectomy followed by retroperitoneal lymphadenectomy. Nine patients (20.5%) who presented with clinically advanced disease (stages IIC to IV) were treated with primary chemotherapy and secondary retroperitoneal lymphadenectomy of residual masses.

RESULTS

The frequency of lymph node metastases was 19.2% in clinical stage I disease and 66% in stage IIA/B. Histopathological diagnosis of mature teratoma was confirmed in all cases. However, of 20 patients 16 (80%) had scars or calcifications in the adjacent parenchyma, indicating a burned out tumor, and 4 (20%) had microfocal embryonal carcinoma. None of the patients with clinical stage I disease had relapse during followup and the relapse rate in those with stage IIA/B disease was 33%. Median followup was 97 months (range 24 to 250). Overall 43% of patients with pure teratoma presented with metastatic disease.

CONCLUSIONS

Our data demonstrate the malignant potential of pure testicular mature teratoma. Based on our results metastases in testicular mature teratoma seem to result from metastasizing nongerm cell components undergoing early regression, as demonstrated by the high frequency of burned out tumors. We recommend that serial sections be taken of the orchiectomy specimen in all cases of pure mature teratoma to determine adequate management: retroperitoneal lymphadenectomy in cases of associated scars, calcifications or microfocal malignant germ cell components and surveillance in cases of pure mature teratoma.