Sinonasal neuroendocrine carcinoma in a previously healthy young adult male.

Sinonasal neuroendocrine carcinoma in a previously healthy young adult male.

Sinonasal neuroendocrine carcinomas (SN-NECs) are rare malignancies, typically affecting older individuals. This case report presents a highly malignant large-cell neuroendocrine carcinoma (NEC) originating from the nasal septum in a previously healthy young adult male. The patient initially presented with symptoms mimicking acute rhinosinusitis, such as nasal obstruction, rhinorrhoea and frontal headache, which were followed by recurrent epistaxis and double vision. Imaging revealed an extensive sinonasal (SN) tumour with local invasion and significant mass effect. Histopathology confirmed a large-cell NEC with a Ki-67 proliferation index of 80%. Urgent surgical resection was performed, followed by cisplatin and etoposide chemotherapy and radiotherapy, leading to a positive response despite complications such as thrombosis and tinnitus. This case highlights the importance of recognising red-flag symptoms, such as double vision, nasal stenosis with recurrent epistaxis and cranial nerve involvement, in SN disease to ensure early diagnosis and timely intervention.