Esthesioneuroblastoma, neuroendocrine carcinoma, and sinonasal undifferentiated carcinoma: differentiation in diagnosis and treatment

Abstract

Introduction Malignant sinonasal tumors comprise less than 1% of all neoplasms. A wide variety of tumors occurring primarily in this site can present with an undifferentiated or poorly differentiated morphology. Among them are esthesioneuroblastomas, sinonasal undifferentiated carcinomas, and neuroendocrine carcinomas. Objectives We will discuss diagnostic strategies, recent advances in immunohistochemistry and molecular diagnosis, and treatment strategies. Data Synthesis These lesions are diagnostically challenging, and up to 30% of sinonasal malignancies referred to the University of Texas MD Anderson Cancer Center are given a different diagnosis on review of pathology. Correct classification is vital, as these tumors are significantly different in biological behavior and response to treatment. The past decade has witnessed advances in diagnosis and therapeutic modalities leading to improvements in survival. However, the optimal treatment for esthesioneuroblastoma, sinonasal undifferentiated carcinoma, and neuroendocrine carcinoma remain debated. We discuss advances in immunohistochemistry and molecular diagnosis, diagnostic strategies, and treatment selection. Conclusions There are significant differences in prognosis and treatment for esthesioneuroblastoma, neuroendocrine carcinoma, and sinonasal undifferentiated carcinoma. Recent advances have the potential to improve oncologic outcomes but further investigation in needed.

Keywords: esthesioneuroblastoma; neuroendocrine carcinoma; olfactory neuroblastoma; sinonasal malignancy; sinonasal undifferentiated carcinoma.

Fig. 1

(A) Low-grade esthesioneuroblastoma with lobules and sheets of monotonous-looking cells, featuring nuclei with no atypia and scant cytoplasm, abundant neurofibrillary background, and vascularized stroma. (B) High-grade esthesioneuroblastoma with solid pattern and decreased neuropils, increased cytologic atypia, and mitosis. (C) Carcinoid, with cords of uniform, bland cells with central nuclei and moderate granular cytoplasm. (D) High-grade neuroendocrine carcinoma, small cell type with sheets, ribbons, and clusters of small to medium-sized cells with minimal cytoplasm; hyperchromatic, indistinct nucleoli; nuclear molding; and frequent mitotic figures. (E) Low-power sinonasal undifferentiated carcinoma with lobules of pleomorphic cells and lack of squamous/glandular differentiation. (F) Sinonasal undifferentiated carcinoma high-power magnification of large, round cells with prominent nucleoli and varying amount of cytoplasm.