Expression of cytokeratins in glioblastoma multiforme.

Little is known about the cytokeratin (CK) expressions in glioblastoma multiforme (GBM). The aim is to explore the CK expression in GM using immunohistochemistry (IHC). IHC study in 30 cases (median = 68 years, SE = 12.6) of GBM in brain. CK expression using AE1/3 antidody was seen in 29/30 (97 %) cases. There were no expressions of CK34BE12, CK5, CK6, CK7, CK8, CK14, CK 18, CK19, and CK20. Expression of p53 and glial fibrillary acidic protein (GFAP) were recognized in all 30 cases (100 %). All cases showed Ki-67 antigen labeling, index of which ranged from 6 to 43 % (m ± SD = 24 + 16). The IHC using CKAE1/3 in GBM very frequently shows positive reaction. The expression may cause difficulty in pathologic diagnosis in GBM, particularly in discrimination between GBM and metastatic carcinoma. The CK positivity in GM may be due to CK molecules other than CK34BE12, CK5, CK6, CK7, CK8, CK14, CK18, CK19 and CK20. GBM frequently expression p53 and high Ki-67 labeling.