A case of olfactory neuroblastoma of the left nasal cavity

Abstract

Background : Olfactory neuroblastoma, an uncommon neoplasm, is thought to originate from the olfactory membrane of the upper nasal cavity. This paper describes the cytologic findings of an imprint smear in a case of this tumor.

Case : A man in his 50’s presented with a mass in the left nasal cavity measuring 22 mm in diameter. Imprint cytology of the nasal tumor showed the tumor cells with scanty and fibrillary cytoplasm, round to oval nuclei, overlapping nuclei, fine granular nuclear chromatin, and indistinct nucleoli. Homer Wright rosette formation was observed. The histological preparations showed tumor cells morphologically resembling the cells observed on imprint cytology, forming solid or alveolar structures separated by bands of hyalinized connective tissue. On immunohistochemical analysis, the tumor cells were positive for synaptophysin, but focal staining for calretinin, and S-100 protein staining was limited to the sustentacular cells.

Conclusion : In cases with nasal cavity tumors in which imprint cytology reveals the presence of numerous small round cells, it is necessary to arrive at the correct diagnosis by comprehensively considering this finding together with clinical information and the immunohistochemical findings.