Austin J Otolaryngol. 2014;1(4): 1.
Fenggang Yu1*, Lin Tao1, Fredrik Petersson2, Kwok Seng Loh3
1Department of Otolaryngology, National University of Singapore, Singapore
2Department of Pathology, National University of Singapore, Singapore
3Head & Neck Tumor group, National Cancer Institute of Singapore, Head &Neck Surgery, Singapore
*Corresponding author: Fenggang Yu, Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
Received: October 29, 2014; Accepted: November 14, 2014; Published: November 19, 2014
Nasopharyngeal carcinoma (NPC) is one of the most common cancers in South East Asia. The high incidence of lymphatic spread and distant metastases are associated with high mortality. It has been proposed that metastasis is initiated by a subpopulation of circulating tumor cells (CTCs). The aim of this pilot study was to isolate and culture CTCs from peripheral blood buffy coats of one NPC patient (Stage IV, T4N3M0). Many small spheres (Figure 1A and 1A’) formed in culture and immunocytochemistry (ICC) was performed on cytospun cells in order to characterize them. Some unknown cells with small round nuclei and abundant cytoplasm (Figure 1B) were positive for EBNA-1, Cytokeratin (pan-CK) and CD45 (Figure 2, 3). In NPC, EBV (detected by ISH; EBER) is exclusively detected in tumor cells, never in lymphocytes. CTCs are supposed to be positive for CK (epithelial lineage), but not CD45 (hematopoietic lineage). Thus they neither resemble typical blood cells nor CTCs. Their identity needs further investigation IRB number.
Figure 1 : Ex vivo expansion of cells from NPC patient’s peripheral blood. Representative images of non-adherent sphere culture. Phase contrast is at 10x (A) and 20x (A’) magnifications. Giemsa staining showing three types of morphology in the cell cytospins. The majority of them exhibit round nuclei and abundant cytoplasm (red arrow).
Figure 2 and 3 : The major cell type expresses Epstein–Barr virus (EBV) marker (EBNA-1,green), epithelial lineage marker (pan-CK,red) and hematopoietic lineage (CD45,red).