Collision tumor of squamous cell carcinoma and neuroendocrine carcinoma in the head and neck:A case report

BACKGROUND There are many disputes about the definition,diagnosis,therapy,and prognosis of collision tumors.CASE SUMMARY We describe a rare patient with a collision tumor consisting of neuroendocrine carcinoma(NEC)and squamous cell carcinoma(SCC)in the nasal cavity and paranasal sinus.She received operation,concurrent chemoradiotherapy,and then two cycles of palliative chemotherapy.Follow-up at 12 mo after diagnosis showed that this patient experienced a complete response with no signs of recurrence or metastasis.A literature review of previous 26 cases diagnosed with collision tumor of NEC and SCC in the head and neck was also undertaken.CONCLUSION It is challenging to manage collision tumors because there are two morphologically and etiologically distinct tumors.Well-designed multimodality therapy including surgery and chemoradiotherapy might lead to a long survival in these patients.