Sinonasal nonsalivary-type adenocarcinoma: A 9-year experience from a tertiary cancer center in South India

Background: Sinonasal tract malignancies are uncommon, representing not more than 5% of all head and neck neoplasm. Primary non-salivary type adenocarcinomas of the sinonasal tract are rare and may originate from respiratory surface epithelium or the underlying seromucinous glands. They are classified into intestinal type adenocarcinoma (ITAC) and non-intestinal type adenocarcinoma (non-ITAC) based on immunophenotypic features. Materials and Methods: We retrieved five cases of ITACs and twelve cases of non-ITACs from our archives over a period from 2010-2018. Results: All cases of ITACs occurred in the nasal cavity. There was a male predilection with ratio of 4:1, mean age being 48 years. Two cases had association with occupational risk factors. All cases showed positivity for CK20. Non-ITACs occurred in older age group with mean age of 52 years. Male to female ratio was 2:1. Apart from nasal cavity, ethmoid, maxillary, frontal and sphenoid sinuses were involved. Though occupational risk factors have not been established for non-ITAC, five of our cases gave history of exposure to risk factors. Non-ITACs showed positivity for CK7 and were negative for CK20. Conclusion: Surgery is the first line of management followed by adjuvant radiotherapy. Three cases of non-ITACs developed recurrence while on follow up. Recurrence in one case was after five years of initial diagnosis. Follow-ups over long period of time are required. Multiinstitutional studies are needed for better understanding these rare cancers.