Clinicopathological evaluation of immunohistochemical Ki-67 and endothelial nitric oxide synthase expression in intracranial ependymoma

Abstract

Clin Invest Med 2008; 31 (4): E206-E211. AbstractPurpose: To analyze the association between Ki-67 and eNOS expression with the pathological grades of patients with intracranial ependymomas, and to determine its value in distinguishing the progression of the disease. Methods: A clinicopathological study was undertaken in 82 patients with intracranial ependymomas. Tissue samples, obtained by tumour resection, were divided into three groups: low-grade, mid-grade and high-grade ependymomas. Tissue samples obtained from 15 patients with brain contusion were used as control. Immuno-histochemical staining was performed to analyze the association between Ki-67 and eNOS expression with various tumour grades. The cell proliferating marker Ki-67 was assessed by positive cell count. The levels of eNOS positive expression were evaluated as slight, moderate and intense. Results: 48 of 82 cases (58.54%) expressed Ki-67 protein.Expression of Ki-67 and eNOS was negative in all control samples. Positive cell rates were 2.65±0.83 % in the lowgrade, 9.63±0.08 % in the mid-grade, and 28.41±0.71 % in the high-grade ependymoma groups. In low-grade ependymomas there were 8 and 12 cases that expressed eNOS slightly or moderately. In the mid-grade ependymoma group eNOS was expressed moderately in 10 cases and intensely in 15. In the high-grade group 20 cases showed intense positive expression of eNOS. The Ki-67 positive cell counts for slight, moderate and intense eNOS expression were 2.20, 6.07 and 22.25, respectively. Conclusion: Ki-67 and eNOS expression in intracranial ependymoma tissue was associated with the histopathological grade and malignant degree.Ependymomas and malignant ependymomas constitute approximately 2%~9% of all intracranial carcinomas and 18.2% of nervous epithelium tumours. 1 After pilocytic astrocytoma and medulloblastoma, ependymomas are the third most common brain tumours in children. In adults, most ependymomas are intraspinal but, in children, these tumours develop preferentially in the posterior fossa where they arise from the fourth ventricle ependymal cells. 2 The prognosis remains poor, regardless of introduction of radiotherapy or chemotherapy in the treatment protocol. Age, surgical removal, tumuor location and histology have been evaluated as important factors affecting ORIGINAL RESEARCH

NOS Expression and NO Function in Glioma and Implications for Patient Therapies

“…NOS1 strongly correlated with astrocytoma grade and proliferation (115), and NOS3 was strongly correlated with astrocytoma grade and VEGF expression (26). NOS3 expression also correlated with elevated tumor grade for ependymomas (134). Elevated expression of NOS2 was also observed in the majority of oligodendrogliomas (10).…”

Cytoplasmic immunoreactivity for Ki67 in an invasive amelanotic melanoma - foe or faux pas?

“…In a previous study, cytoplasmic staining for Ki67 was identified in 15% (24/155) of cryostat‐sectioned snap‐frozen primary melanomas 4 . A cytoplasmic and/or cell membrane pattern of immunoreactivity for Ki67 has also been described in tonsil crypt epithelial cells and fetal epithelial lung cells, and in a number of tumors, including basal cell carcinoma, intracranial ependymoma, hyalinizing trabecular adenoma of the thyroid gland, sclerosing hemangioma of the lung, pleomorphic adenoma of the salivary gland, sarcomatoid pleural mesothelioma, renal oncocytoma and 4.7–26% of invasive breast carcinoma cases 1,2,5–9 . In addition, in vitro cytoplasmic localization of Ki67 has been reported in HeLa cell line cultures 10 …”