Teratoma with a malignant somatic component in pediatric patients: the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) experience.

Background: Teratoma with a malignant somatic component (TMSC) is rare but described in adults, whereas information on pediatric presentation is sparse.
Procedure: The Associazione Italiana Ematologia Oncologia Pediatrica identified 14 cases of TMSC. Clinical files and pathology specimens were reviewed.
Results: The series (9 female, 5 male) showed the following disease: testis (2), sacrococcygeal (3), ovary (3), retroperitoneum (3), mediastinum (2), and foot soft tissue (1). Distribution of the somatic component was: carcinoma (4), pancreatic neuroendocrine tumor (1), neuroblastoma (3), rhabdomyosarcoma (3), rhabdomyosarcoma plus liposarcoma, chondrosarcoma, neurogenic sarcoma (1), chondrosarcoma plus neuroectodermal sarcoma (1), malignant peripheral nerve sheath tumor (1). Three patients were in stage I, four in stage II, three in stage III, and four in stage IV. All but one patient underwent surgery and only females showed carcinoma components. Nine patients relapsed or progressed and eight died. Six patients are alive and disease-free. Two patients underwent complete resection and four were treated based on transformed histologies. Relapse-free and overall survival rates were 35.7% and 42.8%, respectively (median follow-up, 31 months).
Conclusions: Prognosis for germ cell tumors (GCTs) containing MSC is worse than that for GCTs. The pediatric disease appears to be more heterogeneous in tumor site distribution and MSC histology than in adults. Our series suggests no effects of age, histology, or gender on outcome. Surgery has an essential role in localized disease, with complete resection highly desirable. Chemotherapy optimized for histology should include reagents directed to the somatic malignancy, if chemosensitive. Malignant GCT warrants GCT-directed chemotherapy.