Malignant Small Round Cell Tumor Originating In The Thoracopulmonary Region " Askin Tumor "

SUMMARY Askin tumor is a peripheral neuroepithelioma originating in chest wall. It is a very aggressive tumor and with Ewing's sarcoma are the most frequent tumors of chest wall. The tumor is composed of small round or ovoid cells arranged in sheets with pseudorossette formation. Some times around vessels, glycogen staining is some times positive in H & E but always positive in E.M. In E.M because of presence of neurosecretory granules and intermediate (Neuro) filaments they are supposed to have neuronal or1gm. On immunohistochemistry almost all of them are NSE+ and all neuronal antigens save for cbromogranine are variously positive in the cells. Genetically the cells have t(l l ,22) and in oncologic study they express the C.myc gene. They are very aggressive clinically and the survival for them is about 8 months after diagnosis the treatment is the same as Ewing's sarcoma.