Sinonasal Carcinomas with Neuroendocrine Features: Histopathological Differentiation and Treatment Outcomes

Abstract

Objectives Sinonasal cancers with neuroendocrine features share similar clinical, radiological, and histopathological features; however, these tumors often exhibit varying degrees of aggressive behavior presenting significant treatment challenges. The objective of this study was to report our experience with these rare malignancies and to present a review of current literature. Methods Following institutional review board approval, the records of all patients with biopsy-proven sinonasal malignancies over a 5-year period were reviewed. Results The study included 14 patients with olfactory neuroblastomas (ONBs), 7 patients with sinonasal undifferentiated carcinomas (SNUC), and 2 patients with sinonasal neuroendocrine carcinomas (SNEC). Histopathologic markers aided in final diagnosis, but showed variable specificity. In patients with sufficient follow-up, the 2-year disease-free survival rate was 81% (9/11) for ONB and 75% (3/4) for SNUC. Three patients developed a regional or distant recurrence (two with ONBs and one with SNUC). Two patients, one with SNEC and one with ONB, succumbed to brain radionecrosis related to proton radiation therapy. Conclusions Overlapping clinical and histopathological features in poorly differentiated sinonasal cancers with neuroendocrine features continue to present a diagnostic challenge. Individualized assessment and treatment strategies can improve the accuracy of the initial assessment and the treatment outcomes.

Keywords: esthesioneuroblastoma; olfactory neuroblastoma; sinonasal cancers of neuroectodermal origin; sinonasal cancers with neuroendocrine features; sinonasal carcinoid; sinonasal large cell cancer; sinonasal neuroendocrine carcinoma; sinonasal small cell cancer; sinonasal undifferentiated carcinoma.

Fig. 1

Sinonasal carcinomas with neuroendocrine features: Classification.

Fig. 2

Sinonasal carcinomas with neuroendocrine features. (A) T1 coronal MRI of SNUC tumor diagnosed in a 45-year-old female patient and treated with neoadjuvant chemotherapy, endoscopic surgical debulking, and proton beam therapy to the surgical bed and bilateral neck. (B) T1 coronal MRI of large cell neuroendocrine carcinoma diagnosed in a 66-year-old male patient and treated with endoscopic gross total resection followed by chemotherapy and proton beam radiation to the surgical bed, bilateral neck, and supraclavicular fossa. MRI, magnetic resonance imaging; SNUC, sinonasal undifferentiated carcinomas.