Management of pure metastatic teratoma in chemotherapy naïve testis cancer patients.

e16043 Background: Management of metastatic testicular cancer often requires post-chemotherapy resection of teratoma. This is well known and described in literature. However, the ability of teratoma to metastasize independently is not as well appreciated, making chemotherapy futile in patients with pure metastatic teratoma. Methods: 15 patients with metastatic teratoma were identified of which 13 had only teratoma in the orchiectomy and 2 had predominantly teratoma. All 15 had normal serum hCG and AFP. Cases were derived from a retrospective review of patients seen from 1989-2016. Results: Mean age of patients was 27 years. 12 patients presented initially with Stage II disease and 2 presented with stage III disease. Median RP mass size was 6 cm with a range of 1.5-24 cm. 2 of 15 patients were treated initially with a single course of chemotherapy with BEP and showed no response. The remaining 13 patients only received resection(s). All 15 patients underwent RPLND with 2 patients requiring additional mediastinal and retrocrural resection and 1 requiring lobectomy. All surgical specimens showed pure teratoma on pathology with no other active germ cells. Patients were followed for a median duration of 5 years and all 15 remain with no evidence of disease at most recent follow up. However, 1 patient needed subsequent surgery for a late relapse of teratoma and 1 patient had a second extra-gonadal primary. Conclusions: Teratoma can metastasize in the absence of other germ cells. Surgical treatment alone for patients with pure metastatic teratoma of any stage can result in cure for the majority of patients and this approach can help avoid unnecessary chemotherapy.