K-ras codon 12 and p53 mutations in biopsy specimens and bile from biliary tract cancers.

To evaluate whether it is useful for diagnosis to detect K-ras and p53 mutations in biopsy specimens and bile of biliary tract lesions, 12 cholangiocarcinomas (CC), eight cases of cholangitis, seven gallbladder carcinomas (GBC), seven gallbladder cholesterol polyps, four cases of adenomyomatosis of the gallbladder and five cases of cholecystitis were examined. K-ras and p53 mutations in bile were detected by a two-step polymerase chain reaction (PCR) and nested PCR-single-strand conformation polymorphism (SSCP) analysis. In addition, p53 protein expression in biopsy specimens from CC were examined by immunostaining. K-ras mutations at codon 12 were detected in 50% of CC and 57.1% of GBC in both biopsy specimens and bile. The incidence of p53 mutations was 33.3% in CC and 42.9% in GBC. p53 protein overexpression was observed in 60% CC biopsy specimens. In contrast, K-ras and p53 abnormalities were not detected in any non-neoplastic biliary tract lesion. K-ras and p53 mutations in biliary tract cancers showed the same mutation patterns in spite of differences in the collection methods used between bile and biopsy specimens or surgically resected tissue. Genetic analysis of K-ras and p53 mutations in biopsy specimens and bile may be useful for the diagnosis of biliary tract cancers, although it may be effectively limited to patients with advanced disease.

Enzyme histochemical, immuno histochemical and electron microscopic studies of two cases of leukemic malignant histiocytosis.

Two cases of leukemic malignant histiocytosis had similar morphologic and enzyme histochemical findings. Large blasts with low nuclear/cytoplasmic ratios, occasional azurophilic granules, and immature nuclei with nucleoli were seen in peripheral blood and bone marrow smears. Case 1 had occasional erythrophagocytosis, while in Case 2 it was rare. They were peroxidase negative, and very strongly positive by alpha-naphthyl butyrate esterase stain, the latter being inhibited by sodium fluoride. Acid phosphatase stains were also very strongly positive and were inhibited with tartaric acid. They were also stained granularly with PAS. Surface marker analysis revealed myeloid surface antigens, CD11+, CD13+ and HLA-DR+ in Case 1, and CD11+, CD13+, CD33+ and HLA-DR+ in Case 2. Immunoperoxidase stains of bone marrow biopsies revealed that lysozyme was positive in both cases. S-100 protein was strongly positive in Case 1, but weakly so in the skin tumor and negative in the bone marrow of Case 2. Electron microscopy showed both cases to be myeloperoxidase negative and rich in cytoplasmic organelles, such as lysosomes, mitochondria, and endoplasmic reticuli. Nuclei were irregularly shaped and nucleoli were present in virtually all the cells. These findings suggest that the malignant histiocytes in these two cases derive from bone marrow macrophages, and S-100 protein can also be detected in monocyte-macrophage derived histiocytes.