[734] Teratoma with Malignant Transformation in Adult Testis: 25-Years Experience at Istituto Nazionale Tumori of Milan

M Colecchia, A Necchi, N Nicolai, M Di Nicola, L Piva, R Salvioni. Fondazione IRCCS Istituto Tumori Milano, Milan, Italy

Background: The presence of teratoma with malignant somatic transformation (TMT) is a rare phenomenon: though lacking large-scala data, TMT seems to associate with shorter survival and in metastatic cases best treatment modality is not still established. We reviewed our 25-years experience in primary TMT of the testis and in cases with development of malignant somatic transformation in metastatic sites following chemotherapy for advanced testicular germ cell tumors.
Design: A total number of 28 patients with TMT was recorded from consultation or surgical pathology files at Istituto Nazionale Tumori of Milan from 1983 to 2007. The case histories and slides were reevaluated.
Results: 10 out of 28 patients had TMT in the primary only, 2 both in primary and metastatic sites and 16 had post-chemotherapy metastatic malignant transformation. The histology of TMT in the testis was: chondrosarcoma (2 cases), rhabdomyosarcoma (2), leiomyosarcoma (1), sarcoma Nas (5),while two cases (1 nephroblastoma and 1 PNET) occurred with simultaneous metastases . Among TMT in metastatic sites (retroperitoneum, lung, lymphnodes, mediastinum and bone) we observed rhabdomyosarcoma (4 cases), PNET (2), adenocarcinoma (4), leiomyosarcoma (2), sarcoma with neural differentiation (3) and 1 sarcoma Nas. All the 10 patients but one (91.6%) with TMT only in primary tumor were free of disease (mean follow-up 223.5 months). One patient died perioperatively. 14 out of 16 patients who had TMT in metastases were evaluable: these who were submitted to a radical excision of metastases had better outcome (7/8). Seven patients died after chemiotherapy and surgery (1 rhabdomyosarcoma, 2 PNET, 2 adenocarcinomas, 1 sarcoma with neural differentiation and 1 nephroblastoma). Rescue chemotherapy was able to cure 4/11 of not radically resectable patients.
Conclusions: Stage of disease at transformation and the feasibility to perform a radical surgical removal of disease seems to be the strongest disease-related prognostic factors in TMT of the testis. Histology of TMT at the primary site seems not to be a significant predictor of outcome, while the development of PNET in metastatic sites following chemotherapy is associated with a poor prognosis.
Category: Genitourinary (including renal tumors)

Monday, March 9, 2009 1:00 PM

Poster Session II # 99, Monday Afternoon