An Extremely Rare Case of Advanced Metastatic Small CellNeuroendocrine Carcinoma of Sinonasal Tract

Small cell neuroendocrine carcinoma (SNEC) is a rare form of malignancy. It mainly presents as bronchogenic neoplasm, andthe extrapulmonary form accounts for only 0.1% to 0.4% of all cancers. These extrapulmonary tumors have been described mostfrequently in the urinary bladder, prostate, esophagus, stomach, colon and rectum, gall bladder, head and neck, cervix, and skin.Primary SNEC of the sinonasal tract is extremely rare with only less than 100 cases reported in the literature. Because of extremerarity and aggressiveness of the tumor, the management for this entity varies considerably mandating multimodality approach. Inthis paper, we report a patient presented with left-sided facial swelling, and the histopathologic examination confirmed primarySNEC of left sinonasal tract. The tumor involved multiple paranasal sinuses with invasion into the left orbit and left infratemporalfossa and metastasized to cervical lymph nodes and bone. The patient encountered devastating outcome in spite of optimal medicalmanagement and treatment with palliative chemotherapy highlighting the necessity for further research of primary SNEC of headand neck.