[Primitive neuroectodermal tumor].

The primitive neuroectodermal tumor is a rare soft tissue neoplasm occurring in children and young adults. It derives from a carcinogeneic alteration of pluripotent neural crest cells, caused by a balanced reciprocal translocation t(11;22) (q24;q12). Treatment of this undifferentiated, extremely malignant small cell tumor is carried out in compliance with the soft tissue trail (CWS) from the German Society of Pediatric Oncology. Biopsy-proven diagnosis is followed by primary chemotherapy, which in 95% of cases leads to remission, allowing excision of the remainder of the tumor without mutilation and avoidance of intraoperative tumor cell dissemination. After excision, irradiation of the tumor site and two further sequences of chemotherapy are performed. If PNETs of the paravertebral region cause symptoms of paralysis and immediate surgery is required, postoperative chemotherapy, a second-look operation and irradiation are mandatory. Between 1986 and 1994, in cooperation with our pediatric and radiotherapy colleagues, we treated ten patients. In four patients (median age, 14 years) the PNET originated from the chest wall, in six patients from the paravertebral and retroperitoneal region. Five patients died after 20 months on average, while the remaining five patients are in full remission after 31, 46, 50, 51 and 91 months, respectively.