A CASE OF PRIMITIVE NEUROECTODERMAL TUMOR (PNET) SO-CALLED ASKIN TUMOR ARISEN FROM THE CHILD'S BREAST

Abstract

A case of primitive neuroectodermal tumor (PNET), so-called Askin tumor arisen from the breast in a 14-year-old girl is reported. The patient was admitted to the hospital because of a left breast tumor. The tumor extended the entire left breast and the swelling was remarkable. Chest CT revealed internally heterogeneous tumor shadow with concomitance of low-density area which might be necrosis. And metastatic foci in the bilateral lung fields and lymph nodes of the left armpits were revealed. Under a suspicion of malignant breast tumor, a standard radical mastectomy was performed. The resected breast tumor was 25×25×20cm in size and 3.9kg in weight. The light microscopic findings disdosed remarkable increase in small round cells with rosette formation partially on HE staining, and granules of glycogen on PAS staining. Immunohistochemically, neuron specific enolase (NSE) and S-100 protein staining showed negative. Electromicroscopic finding showed tumor cells poor in small organs, and some amount of junctional complex and neuro-secretory granules. Therefore, she was diagnosed as having a peripheral PNET.