Immunoreactive calcitonin in amyloid fibrils of medullary carcinoma of the thyroid gland. An immunogold staining technique.

A lymph node containing metastatic medullary carcinoma of the thyroid gland was examined immunohistochemically for the presence of calcitonin by light and electron microscopy. Electron microscopy showed dense, selective labeling of the tumor-associated amyloid fibrils and labeling of the scanty intracytoplasmic neurosecretory granules. By light microscopy, a few tumor cells showed strong staining, whereas the amyloid fibrils showed equivocal staining.

Keratin proteins and carcinoembryonic antigen in synovial sarcomas: an immunohistochemical study of 24 cases.

Twenty-four synovial sarcomas were examined for the presence of keratin proteins by an indirect immunoperoxidase method with paraffin-embedded tissues. Keratin proteins were identified in 16 of 24 cases (67 per cent). Both the pseudoglandular and spindle cell areas of all eight of the biphasic synovial sarcomas and the spindle cells of eight of the 16 monophasic synovial sarcomas contained keratin proteins. In spindle cell areas, staining was observed in single cells and small cords and clusters of cells in the absence of cleft formation or other evidence of a pseudoglandular component. The predominant cytologic staining pattern in all cases was peripheral, with localization of staining to the cell membrane or adjacent areas, but diffuse and focal cytoplasmic staining patterns were also observed. No staining for keratin proteins was seen in 101 control cases, including 52 sarcomas of various types. Carcinoembryonic antigen was also identified in four of the 24 synovial sarcomas by an indirect immunoperoxidase technique. The identification of keratin proteins may be helpful in the pathologic diagnosis of synovial sarcoma, particularly the spindle cell monophasic variant.

1,25-dihydroxyvitamin D3 and breast cancer.

Studies by this laboratory have demonstrated the presence of specific, high affinity 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) receptors both in surgical specimens of human breast cancer and in breast cancer cells in culture. We report here that 1,25-(OH)2D3 receptors were found in 54% of 230 human primary breast cancers. Although receptor levels are lower than those of oestrogen receptors, using a modified and more sensitive assay method, the apparent receptor concentration is increased without altering the receptor positivity rate. Also in preliminary studies on lymph node metastases and their primary tumours, the receptor positivity rate is higher in the lymph nodes. These findings suggest that metastatic cells may be selected for the presence of 1,25-(OH)2D3 receptors. These data, taken with the evidence that 1,25-(OH)2D3 and several of its metabolites inhibit the growth of human breast cancer cells in culture, exactly analogously with the effects of oestrogens on cancer cell growth in vitro and in vivo, indicate that 1,25-(OH)2D3 or its metabolites could have a role in the 'hormonal' therapy of metastatic human breast cancer.

Oestrogen receptors in breast cancer: a changing concept.

Oestrogen receptors were found in 156 (73%) out of 214 primary breast cancers and in 98 (58%) out of 168 metastatic deposits. These proportions reached 82% and 70% respectively in the second half of the study. Receptors were not found in samples of normal breast tissue but small amounts were present in tissue from some hyperplastic lesions and in male gynaecomastia. Receptor concentrations in the malignant samples were evenly distributed over a wide range of values, suggesting that even "negative" tumours might contain trace amounts undetectable by the method used. Each tumour was characterized by a given level of receptor concentration. In most cases the amounts found in the invaded axillary nodes and their corresponding primary tumours were the same. We suggest that quantitative rather than qualitative assessment should provide an appropriate criterion for studies of biochemical and clinical correlations.