Alexandra Athanasiou, Presenter: Nothing to Disclose

Daniel Vanel MD, Abstract Co-Author: Nothing to Disclose

Christine Theodore MD, Abstract Co-Author: Nothing to Disclose

Karim Fizazi MD, Abstract Co-Author: Nothing to Disclose

To describe the CT and MR findings of non germ-cell malignant tumors arising in germ-cell tumors (also designated as teratoma with malignant transformation or TMT).

The files of 14 males with TMT were reviewed retrospectively. All patients underwent a CT or MR examination before and after initial surgery and chemotherapy as well as after transformation. Histological correlation (initial tumor and transformation) was obtained in all cases. Imaging findings were associated with response to treatment and with overall prognosis. Genetic research of specific chromosomal changes was also taken into account after the final diagnosis of malignant transformation was made.

Initial diagnosis comprised 6 mixed non-seminomatous tumors, 4 embryonal carcinomas, 3 immature teratomas, and 1 mature teratoma. Initial lesions were 6 testes, 6 mediastinum, one retroperitoneal, and one associating both mediastinum and retroperitoneum. Transformations were mediastinal (7) or retroperitoneal (4), intraperitoneal (2) and one chest. The imaging findings of the initial tumors were in accordance with the histology. Rhabdomyosarcoma was the most frequent histological type of TMT occurring in 6 out of 14 patients, followed by 2 osteosarcomas, 2 adenocarcinomas, 3 undifferentiated sarcomas and 1 bronchoalveolar carcinoma. CT and MR findings of TMT consisted of soft-tissue heterogeneously enhancing masses, ossified masses associated with calcified lymph nodes, diffuse epiploic thickening associated with ascites and peritoneal nodes, or pulmonary alveolar infiltration with septal thickening. TMT occurred between 2 and 7 years after the treated initial tumor. All but one patient were N+ and M+ at the time of TMT. Overall survival was poor, with only 5 out of 14 patients surviving at 5 years.

TMT is rare but associated with a poorer survival compared with germ-cell tumours. Imaging can be useful as CT and MR findings can reliably indicate this entity leading to an early biopsy and appropriate treatment.

Athanasiou, A, Vanel, D, Theodore, C, Fizazi, K, Imaging Findings of Teratoma with Malignant Transformation (TMT).  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4410818.html