[Positive expression of c-myc and p53 products in two cases of pulmonary sclerosing hemangioma].

The c-myc and p53 genes are thought to be an oncogene and a tumor suppressor gene, respectively. These genes' products are characteristic of malignant tumors. We quantitatively analyzed the c-myc and p53 products by flow cytometry in two cases of pulmonary sclerosing hemangioma. In case 1, 32.3% of the tumor cells were found to have the c-myc product, and 8.9% were found to have the p53 product. In case 2, 6.7% of the tumor cells were found to have the c-myc product and 15.5% were found to have the p53 product. The percentages in both cases were twice as high as those in a negative control lymphocytes stained with c-myc and p53 products. Therefore, these two cases showed positive expression of the c-myc and p53 products. In addition DNA from six other patients with sclerosing hemangioma was analyzed with paraffin-embedded sections. All six had DNA diploidy, with DNA indexes ranging from 0.91 to 1.03 and coefficients of variation ranging from 3.0 to 5.5. We suggest that pulmonary sclerosing hemangioma is a very weakly malignant tumor.