Cytoskeleton and motility: an immunohistological and computer simulation analysis of melanocytic skin tumors

Immunohistochemical studies on expression of human vascular smooth muscle myosin heavy chain isoforms in normal mammary glands, benign mammary disorders and mammary carcinomas

The expression of myosin in normal and diseased mammary glands of 199 Japanese women was evaluated immunohistochemically by the avidin-biotin peroxidase complex method using antibodies to three human smooth muscle myosin heavy chain isoforms derived from the vascular smooth muscle: myosin SM1 is expressed consistently from fetal stage to adulthood, myosin SM2 appears only in well-differentiated smooth muscle after birth, and myosin SMemb is more abundant in embryonic aortas. SM1 was expressed in myoepithelial cells of normal mammary glands and fibrocystic diseases and in myoepithelial-like tumor cells in the basal layer of fibroadenomas and phyllodes tumors. SM2 was expressed only in the myoepithelial cells of mammary glands in breastfeeding women. SMemb was expressed more intensely in the cytoplasm of luminal epithelial cells in larger fibroadenomas (P< 0.01), or in the cytoplasm of carcinoma cells in invasive ductal carcinomas with metastasized lymph nodes (P< 0.001) and in those of higher histological grade (P<0.0001). Multivariate logistic analysis showed a significant correlation only between the expression of SMemb and histological grade (P< 0.0001), which is a prognostic factor of mammary carcinomas. These findings suggested the possible prognostic value of SMemb.

Melanoma and stroma: an interaction of biological and prognostic importance

Stromal relationships are crucial to metastatic spread of solid malignancies. Some aspects of this stroma interaction are obviously associated with particular morphological features, which may carry prognostic significance. In cutaneous melanoma, level of invasion, arrangement of cells (horizontal or vertical growth phase), neovascularization, vessel invasion, architecture of the border, and inflammatory infiltrate have been examined. Expression of adhesion molecules, signalling factors, cytoskeletal components, extracellular matrix molecules and matrix-degrading enzymes have been assessed by immunohistology and in situ hybridization. Besides providing prognostic information, a thorough evaluation of stromal relationships may help to increase our knowledge about factors mediating the growth and metastatic spread of malignancies.

Computer simulations of histologic patterns in melanoma using a cellular automaton provide correlations with prognosis

Computer simulations have been used frequently in the life sciences to investigate the mechanisms of morphologic pattern formation. The cellular automaton program SMN5 is designed to simulate tumor growth and to estimate biologic properties by comparing real tumor patterns with computer-simulated reference patterns. This method was applied to 195 cases of primary melanoma of the skin. S-100-stained sections were evaluated by image analysis and compared statistically to a reference set of 4000 simulated patterns. Estimates of tumor cell proliferation, motility, cell loss, cohesion, stroma destruction, and intercellular signals (autocrine and paracrine factors affecting growth, motility, and cell loss) were calculated. Twelve of 18 estimated parameters correlated significantly with tumor progression, as indicated by vertical tumor thickness (linear regression analysis: p < or = 0.05), and 13 of 18 parameters carried prognostic significance (log rank test: p < or = 0.05). Poor prognosis was associated particularly with a pronounced increase in the estimates of proliferation, tumor cell motility, and stromal degradation. Poor prognosis was also associated with a decrease in the estimates of cell loss, tumor cell cohesion, and paracrine growth factor dependence. In multivariate analysis using Cox's proportional hazard model, stromal degradation and motility showed prognostic information in addition to conventional prognostic parameters. The study shows that analytical comparison of real tumors with computer-simulated patterns of a cellular automaton facilitates a functional interpretation of tumor morphology, which carries prognostic significance in cutaneous melanoma.

Image analysis in dermatopathology

BACKGROUND/AIMS

Image analysis in dermatopathology has been used for DNA ploidy analysis, morphometry, stereology, and quantitative immunohistochemistry. The object is to review image analysis in dermatopathology and evaluate these modalities and their application in pigmented lesion pathology, for elucidation of tumor behaviour and architecture and as an aid in tumor identification and prognostication.

CONCLUSION

Image analysis in dermapathology has a huge potential. The techniques are difficult and at present mainly used in specialized centres.