Sinonasal Neuroendocrine Carcinoma in a Young Female – A Case Report

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

“…As evidenced in our case, SCNEC of the nasopharynx may present with a yellowish-white mass 5 . Our patient developed SCNEC as a second primary malignancy 4 years after successful completion of CCRT treatment.…”

“…ENB may be positive for cytokeratin only in the Homer Wright pseudorosette areas 4 . S100, LCA and CD99 stains were all negative in our case, thereby ruling out malignant melanoma, lymphoma and small round blue cell tumors 5 . Since SCNEC of the nasopharynx is rare, no specific therapeutic guidelines are available.…”

“…The Ki-67 proliferative index was 99 % (Figure 9). SNUC generally is Synaptophysin and Chromogranin negative 4,5 and ENB is rarely positive for cytokeratin 6 . ENB may be positive for cytokeratin only in the Homer Wright pseudorosette areas 4 .…”

“…Neoplasms of various cellular origin including epithelial (most common) 5,6 , mesenchymal and neuroectodermal differentiation may arise in the sinonasal tract. Malignancies with neuroendocrine differentiation are rare in the sinonasal tract 6 .…”

“…Conventional microscopic histopathologic examination alone does not suffice to arrive at the diagnosis of SCNEC. Further immunohistochemical studies help to exclude other sinonasal neoplasms such as lymphoma, ENB, malignant melanoma, and SNUC 5 . Although SCNEC can be quite similar to ENB morphologically and immunohistologically, there are specific features that can be used to differentiate these two mimickers.…”