EP1.17-12 Multimodal Aggressive Managment for Askin' Tumor: Results and Prognosis About 3 Cases

Abstract

Peripheral primitive neuroectodermal tumor (pPNET) is a highly aggressive small round cell tumor belonging to PNET/Ewing sarcoma family. Askin”s tumor is a rare entity of neuroectodermal pathology that starts from the soft parts of the chest wall. It is observed with predilection in the young subject. Herein ; We discuss follow up of three cases after multimodal therapy. We report the case of three patients aged respectively 18; 20; 60 years; whose main symptom in consultation is the appearance of a thoracic parietal mass gradually increasing in size and painful. The general condition was completely preserved in all three patients; and the clinical examination is without abnormalities apart from clubbing in the person aged on a past of smoking. Imaging revealed the presence of a thoracic parietal tumor, the largest of which was 15 X 10X 6 cm without signs of locoregional or distant extension with weak contrast. The histological diagnosis was made on a transparietal mass biopsy with a conclusive immuohistochemical study in favor of a PNET tumor (Askin'tumor) Management was multimodal with 6 aggressive chemotherapy cycles, followed by extensive carcinologic resection surgery and radiation therapy on the tumor bed. We deplore the loss of a patient after distant recurrence in 8th month ; the other two patients remain alive after 25 and 36 months of progression without recurrence. Askin”s tumor is a bone or extra-bone tumor that is histologically similar to Ewing”s sarcoma and PNET, which is characterized by its thoracic location. These three tumors appear to represent different forms of the same entity. They present the same specific chromosomal translocation (11q24-22q12) and, in immunohistochemistry, the same expression of the MIC2 oncogene (CD99) and of the translocation-related FLI-1 protein. The diagnosis is often made at the late stage of locoregional or remote invasion. The treatment is mainly based on surgery and radiotherapy and postoperative chemotherapy to reduce recurrence. The prognosis is unfavorable with a survival at 2 years not exceeding 40% after treatment. Pulmonary metastases are frequently observed even a few years after surgery.