Diagnostic challenges in malignant tumors of nasal cavity and paranasal sinuses

INTRODUCTION: Malignant tumors of sinonasal tract are extremely rare and comprise 3% of all head and neck malignant tumors. They constitute 0.2% of all invasive carcinomas. Sinonasal space is a small anatomical place, but is the site of origin for tumors with diverse histological features. Many of the tumors are similar to those that occur in various parts of the body and have overlapping histological features. A panel of immunohistochemical (IHC) markers is essential to diagnose these tumors. Most of the tumors arise in the maxillary sinus followed by ethmoid sinus. History and complete head and neck examination along with biopsy are mandatory for evaluating the disease. AIM AND OBJECTIVES: To study the age-, sex- and site-wise incidence of different malignant lesions of the nasal cavity and paranasal sinuses. To subtype and classify the malignant tumors as per the WHO guidelines. MATERIALS AND METHODS: Forty-seven cases of sinonasal tumors reported over a period of 3 years were retrieved from the archives of the department of pathology. The tissues were subjected to paraffin processing and stained with hematoxylin and eosin. IHC was done with a panel of markers, wherever necessary. RESULTS: The present study included a total of 47 malignant lesions. Of which, 24 cases (51.06%) were squamous cell carcinomas (five cases each of well-differentiated SCC and moderately differentiated SCC and 14 cases of nonkeratinizing SCC). Five (10.63%) cases each were of neuroendocrine carcinoma and non-Hodgkin's lymphoma. CONCLUSION: Malignant neoplasms of sinonasal tract have overlapping clinical and pathological findings; establishing the correct diagnosis is difficult without using a panel of IHC markers.