We examined the expression of MUC1, MUC2, MUC5AC, and MUC6 by immunohistochemical staining in atypical adenomatous hyperplasia (AAH), bronchioloalveolar carcinoma (BAC), and adenocarcinoma with mixed subtypes (MX) to study the association between the biologic features of adenocarcinoma of the lung and mucin expression. MUC1 expression was decreased significantly in the progression from AAH through BAC to MX, while the levels of expression of MUC2, MUC5AC, MUC6, and depolarized MUC1 were increased significantly. Alterations in the expression of depolarized MUC1, MUC5AC, and MUC6 were correlated significantly with p53 gene abnormalities. Depolarized MUC1 expression also was correlated significantly with Ki-67 expression, and down-regulation of MUC1 expression and up-regulation of MUC6 expression were correlated significantly with tumor size. Our results suggest that the expression of these mucins might be associated with the progression of adenocarcinoma of the lung.

We examined the expression of MUC1, MUC2, MUC5AC, and MUC6 by immunohistochemical staining in atypical adenomatous hyperplasia (AAH), bronchioloalveolar carcinoma (BAC), and adenocarcinoma with mixed subtypes (MX) to study the association between the biologic features of adenocarcinoma of the lung and mucin expression. MUC1 expression was decreased significantly in the progression from AAH through BAC to MX, while the levels of expression of MUC2, MUC5AC, MUC6, and depolarized MUC1 were increased significantly. Alterations in the expression of depolarized MUC1, MUC5AC, and MUC6 were correlated significantly with p53 gene abnormalities. Depolarized MUC1 expression also was correlated significantly with Ki-67 expression, and down-regulation of MUC1 expression and up-regulation of MUC6 expression were correlated significantly with tumor size. Our results suggest that the expression of these mucins might be associated with the progression of adenocarcinoma of the lung.

Aims: To investigate the importance of gene amplification and EGFR (epidermal growth factor receptor) and HER2 protein expression during the progression of adenocarcinoma of the lung. Methods: EGFR and HER2 gene amplification was examined in atypical adenomatous hyperplasia (AAH), bronchioloalveolar carcinoma (BAC), and adenocarcinoma with mixed subtypes (MX) by chromogenic in situ hybridisation (CISH), and protein expression was examined by immunohistochemistry using paraffin wax embedded tissues. Results: EGFR and HER2 gene amplification was found in four and two of 86 cases, respectively, and was detected only in the invasive components of MX. EGFR and HER2 protein expression was seen in 24 and 18 of 86 cases, respectively. EGFR and HER2 proteins were not expressed in AAH but were expressed in one BAC case each. EGFR and HER2 proteins were expressed in 23 and 17 of 55 adenocarcinomas with MX. EGFR and HER2 protein expression was seen more often in the invasive components than in the BAC components of MX, and increased significantly as lesions progressed from AAH to BAC, early MX, and overt MX. Because EGFR and HER2 protein expression was frequently seen without gene amplification, other mechanisms apart from gene amplification may be associated with protein expression. Conclusions: EGFR and HER2 gene amplification may be a late event and EGFR and HER2 protein expression may be associated with the development of adenocarcinoma of the lung.

We investigated the aberrant promoter hypermethylation of p16, p15 and p14 genes and loss of heterozygosity (LOH) at 9p21-22 in 48 cases of adenocarcinoma of the lung. The frequencies of hypermethylation of genes were as follows: p16, 25.0%; p15, 22.9%; and p14, 18.8%. The frequency of LOH at chromosome 9p21-22 was 60.9%. The frequency of two-hit inactivation of the p16 gene by hypermethylation and LOH was 21.7%. Two-hit inactivation of the p16 gene showed loss of protein expression and was significantly correlated with tumor size, tumor grade and the Ki-67 labeling index. Hypermethylation of the p16 gene was not significantly correlated with hypermethylation of the p15 and p14 genes, both of which are close to the p16 gene locus, suggesting that hypermethylation of these genes occurs selectivity. In conclusion, biallelic inactivation of the p16 gene by hypermethylation and LOH might cause loss of p16 expression and play an important role in the development of adenocarcinoma of the lung. Therefore, controlling and monitoring for hypermethylation of the p16 gene may be partially useful for treatment and early diagnosis of adenocarcinoma of the lung.

A case of myxopapillary ependymoma with anaplastic features in 15-year-old boy is reported. The tumor was located in the intradural space extending to the 12th thoracic to 2nd lumbar vertebral level. It was excised with the accompanying spinal arch of the T12 to L2 vertebra. At operation, the tumor was not attached to the surrounding soft and bony tissues. The tumor, measuring 49 x 19 x 15 mm, was brownish-yellow in color and involved the conus medullaris and filum terminale. Histologically, the tumor was composed of biphasic features of a hypercellular papillary growth area and a hypocellular myxoid area. In the papillary growth area, ependymal rosettes and perivascular pseudorosettes were observed. These findings were consistent with those of a myxopapillary ependymoma, although multiple foci of punctate necrosis within the tumor and proliferation of endothelial cells showing glomeruloid structures were observed. Many mitotic figures were also observed. In addition, the Ki-67 labeling index of tumor cells was 10.1%. These findings are unusual for myxopapillary ependymoma, and therefore, it appeared that the diagnosis of myxopapillary ependymoma with anaplastic features was appropriate.