Neuroendocrine Neoplasms of the Sinonasal Tract: Neuroendocrine Carcinomas and Olfactory Neuroblastoma

Abstract

Neuroendocrine neoplasms (NENs) can occur in organs or tissues that do not contain neuroendocrine cells normally and do not necessarily imply embryologic derivation from the neuroectoderm; but rather reflect a shared phenotype characterized by the expression of multiple genes encoding both endocrine and neuronal features. NENs are rare in the sinonasal tract and are subdivided into epithelial and neural subtypes based on the presence of keratins or neurofilaments, respectively. Although relatively rare, neuroendocrine carcinomas (NECs) and olfactory neuroblastoma (ONB) are the most common neuroendocrine neoplasms of the sinonasal tract. The focus of this review is to highlight recent developments in the pathology of sinonasal NECs and ONB in light of the upcoming update of the World Health Organization (WHO) 2005 classification of tumors of the head and neck.

Aberrant Pattern of Cytokeratin Expression in Olfactory Neuroblastoma: A Potential Diagnostic Pitfall

“…In conclusion our case represents the first demonstration of a ''dot-like'' cytokeratin expression in an ONB, a feature hitherto undescribed to our knowledge and supplements the Literature data [2][3][4][5]. Pathologists should be aware of this potential diagnostic pitfall in distinguishing a high grade ONB from a high grade NEC, particularly in scanty & Martina Mandarano mandaranomartina@gmail.com biopsies [2], in which is crucial an integration of immunohistochemical data with careful interpretation of morphological features.…”

“…In their paper entitled ''Neuroendocrine Neoplasm of the Sinonasal Tract: Neuroendocrine Carcinomas and Olfactory Neuroblastoma'' Shah and Perez-Ordoñez [2] reported a cytokeratins positivity, observed in up to 30 % of ONBs, in accordance with other Authors who documented cytokeratins expression from 23 to 35 % of cases, both focal or diffuse with strongly intensity, but never showing a paranuclear or globoid stain (''dot-like'' pattern). This latter being an important difference respect to Neuroendocrine Carcinoma (NEC) [1][2][3][4][5]. Furthermore another recent article by Holbrook et al [6] demonstrated that cytokeratin 18 (CK18) was positive in ONB separating tumor cells into nests.…”

“…Pathologists should be aware of this potential diagnostic pitfall in distinguishing a high grade ONB from a high grade NEC, particularly in scanty & Martina Mandarano mandaranomartina@gmail.com biopsies [2], in which is crucial an integration of immunohistochemical data with careful interpretation of morphological features.…”

Small cell neuroendocrine carcinoma: A rare second primary malignancy after treatment of nasopharyngeal carcinoma

“…Such sites do not imply embryologic derivation from neuroectoderm. It only reflects a shared phenotype characterized by expression of multiple genes encoding both the neuronal and the endocrine feature 9 . Extra pulmonary SCNECs are rare, accounting for only 0.1 -0.4% of all malignancies 2 and 2.5 -5% of all SCNECs 7 , with the larynx being the commonest extrapulmonary site involved 8 .…”

Clinicopathological Analysis of Undifferentiated Malignant Neoplasms of the Sinonasal tract

“…[15,16] The tumor was disposed in lobules and nests and composed of small round cells with high N/C ratio, small uniform hyperchromatic nuclei with salt and pepper type of chromatin, Homer-Wright rosettes in a fibrillary background with a Hyams grade I (Fig.3). [15,16,17,18] One of our cases had intracranial extension and cervical lymph node metastasis with a Kadish stage C (Fig.4). FNAC of cervical node revealed small round cells with occasional rosette formation confirming metastasis to cervical node.…”