Case Report: Cytodiagnosis of primitive neuroectodermal tumor (PNET) of sinonasal tract

Malignant sinonasal tumors are rarely encountered in the practice of oncology as they constitute only 1% of total body tumors. The occurrence of primitive neuroectodermal tumor (PNET) in the sinonasal tract is even more uncommon. The PNET belongs to Ewing sarcoma family and forms the differential diagnosis of a large group of lesions generally described as malignant round cell tumors. The unique pathogenetic chromosomal alteration in this lesion is the EWS FLI1 fusion gene. This case report describes the unusual occurrence of PNET for its cytomorphological diagnosis along with its clinical features, radioimaging findings and immunohistochemistry. Such case reports are scarce in literature and cytodiagnosis of PNET in sinonasal tracts warrants its sharing with medical fraternity as such diagnoses are stumbled along rarely in clinical practice.