Current topics in pathology. Ergebnisse der Pathologie最新文献

The pathological changes in chronic renal failure are heterogeneous and may depend on the primary disease process. Renal function is better correlated with tubular and interstitial changes than with glomerular changes detectable in simple two-dimensional sections. Atubular glomeruli have been demonstrated in many tubulointerstitial disorders. They constitute a significant portion of the glomerular population in some chronic renal diseases. The atubular glomeruli are generally small, but they have open capillaries and minor ultrastructural changes. The number of capillaries is decreased. Glomeruli connected to normal proximal tubules have volumes at the normal level or above. They have not been shown to be eliminated. The presence of atubular glomeruli may explain the correlation between the volume of proximal tubules and the volume of interstitium, on the one hand, and altered renal function on the other. The presence of atubular glomeruli could explain the irreversibility of chronic renal diseases. It is likely that interstitial fibrosis and tubular atrophy in themselves contribute to the decrease in renal function of both glomerular and nonglomerular renal diseases. In glomerular diseases, the glomerular lesion and hyperfiltration may play the major part in the pathogenesis of the deterioration of renal function. The available evidence points toward glomerulo-tubular disconnection as an important and common cause of progression and irreversibility of chronic renal diseases. It provides a simple explanation for the common observation of severely reduced kidney function and mostly normal-looking glomeruli--at least in two dimensions.

In the preceding, the reader has hopefully developed an appreciation of the major malignant tumors to be encountered in somatic soft tissues in children, adolescents, and young adults. In aggregate, this group of tumors accounts for about 20% of cancer in this age group. Importantly, they are curable tumors when nonmetastatic at presentation, but therapy appropriate to prognosis and tumor responsiveness is highly dependent on precise diagnosis. The historical morphologic methods alone will not suffice for this purpose, but the anticipated rapid advent of molecular genetic diagnostic and prognostic methods should. Useful, practical, and rapid genetic tests, available in the same time frame as the routine histopathologic evaluation of these tumors, are likely to forever change the diagnosis and management of these tumors, individually and as a group.

Characteristic chromosome abnormalities and karyotype profiles are emerging for the soft tissue tumors. The notable findings are summarized in the Table 1. Within the broad range of solid tumors, it is certainly the soft tissue tumors in which the most spectacular success has occurred with regard to neoplasia-associated chromosome abnormalities. Cytogenetic studies of soft tissue tumors have been encouraged by the early and growing supporting interest of pathologists and clinicians concerned with soft tissue tumors. However, when one considers the variety of types and subtypes of benign and malignant soft tissue tumors, the number that has been so far characterized by a specific chromosome change is still very small. But, as we attempt to demonstrate in this report, these data should be viewed as paradigms for the importance of cytogenetic investigations in solid tumors. Cytogenetic studies of solid tumors are of more than clinical interest. Cytogenetic studies allow molecular investigations of the chromosomal breakpoints. They allow the search to proceed for genes involved in the chromosomal changes, providing a better knowledge of the malignant transformation process. In addition, the fruits of the combined efforts in cytogenetic and molecular technologies, from which has come "molecular cytogenetics," will let us recognize more conveniently, more quickly and, hopefully, less expensively the well-characterized diagnostic chromosome markers in tumor cells. Thus, we may be able to reach the goal of incorporating cytogenetics into standard diagnostic procedures for solid tumors, as has been achieved with hematological malignancies. Molecular cytogenetics including fluorescent in situ hybridization (FISH) technology promises to bring soft tissue tumor cytogenetics into regular diagnostic armamentaria and concurrently speed research into the basis of soft tissue tumors.