Primary Pulmonary Primitive Neuroectodermal Tumor of Lung in a Child

Introduction : Peripheral primitive neuroectodermal tumor (pPNET) arising from lung without involvement of chest wall is very rare. Peripheral primitive neuroectodermal tumor are poorly differentiated, highly aggressive tumor of undetermined histogenesis with a tendency toward early metastasis. Diagnosis needs to be established conclusively by histopathology, immunohistochemistry and molecular studies. Presentation of the cases : A 2 year 10-month old child was investigated for fever, cough and cold and was detected to have right intrathoracic cystic mass on imaging. The mass was excised with possibility of pleuropulmonary blastoma. After excision child was referred to our center for decision on further management. Histopathological examination, immunohistochemistry and molecular study for EWSR gene rearrangement proved the diagnosis of Ewing sarcoma. Metastatic work up for our case was negative. Child is currently undergoing chemotherapy and is asymptomatic. Conclusion : Primitive neuroectodermal tumor (PNET) of lung without chest wall involvement in pediatric age group is a rare occurrence. Available literature suggests highly aggressive nature of such tumor. This case report summarizes the differential diagnosis of such rare pulmonary neoplasm in children and role of immunohistochemistry and molecular studies to establish the diagnosis conclusively.