Paranasal Sinus Neuroendocrine Carcinoma: A Case Report and Review of the Literature

Table 1

Histological and immunohistochemical features of sinonasal tumours with neuroendocrine differentiation [4].

Tumor classification	Histology				IHC
	Morphology	Nucleoli	Mitotic	Other	K	SP	CG	S-100	NF
ENB	Small cells sheets	Absent	Low	Homer-Wright rosette, fibrillary cytoplasm	−	+	+	+	+
SNUC	Large cells sheets, nests	prominent	High	Necrosis/no squamous or glandular differentiation	+	−	−	−	−/+
NEC	Small cells sheets, ribbons	Absent	High	Necrosis	+	+	−/+	−	−

ENB: esthesioneuroblastoma, SNUC: sinonasal undifferentiated carcinoma, NEC: neuroendocrine carcinoma, K: keratin, SP: synaptophysin, CG: chromogranin, NF: neurofilaments.