Primary small cell neuroendocrine carcinoma in the nasal cavity: A CARE-compliant case report.

Rationale Small cell neuroendocrine carcinoma of the nasal cavity and paranasal sinuses is a rare but aggressive neoplasm with a poor prognosis and a strong propensity for regional recurrence and distant metastasis. Diagnosis is challenging and relies on immunohistochemical study. Treatment includes surgical resection, radiation therapy, chemotherapy, or a combination of these modalities. However, the optimal therapeutic strategy is still controversial. Due to its rarity, the complexity of the histological diagnosis, and the variety of the treatment regimens, we presented a case of primary small cell neuroendocrine carcinoma in the nasal cavity with description of the clinical manifestation, pathology features, and our treatment regimen. Patient concerns An 82-year-old female patient with hypertension presented with right epistaxis on and off with nasal obstruction for several days. Diagnosis An exophytic mass over the posterior end of the right inferior turbinate was found on nasopharyngoscope. Biopsy was done and the pathology confirmed small cell carcinoma, strongly positive for cytokeratin (AE1/AE3) and insulinoma-associated protein 1 (INSM-1), scatteredly positive for chromogranin A, synaptophysin and CD56. The final diagnosis was small cell neuroendocrine carcinoma of right nasal cavity, pT1N0M0, stage I. Interventions The patient underwent wide excision of right intra-nasal tumor and post-operative radiotherapy with a dose of 6600 cGy in 33 fractions. Outcomes No local recurrence or distant metastasis was noted during the 12 months of follow-up. Lessons Multimodality treatment remains the most common therapeutic strategy, although no proven algorithm has been established due to the rarity of this disease. Further investigation is needed for providing evidence to standardize the treatment protocol.