COMPUTER-ASSISTED QUANTITATIVE DESCRIPTION OF CHROMATIN PATTERN IN SOFT-TISSUE TUMORS OF THE ADULT

The chromatin pattern in Feulgen-stained nuclei from soft tissue tumor s was quantitatively described by means of computer-assisted microscop e analysis. The morphonuclear parameters described densitometric, run length, and co-occurrence matrix features. The present series of cases , which relied upon archival (ie, formalin-fixed, paraffin-embedded), tissues, included 19 benign (9 lipomas and 10 leiomyomas) cases, and 4 9 malignant (31 primitive non-recurrent, 14 primitive locally recurren t, and 4 metastatic) cases. The 31 primitive nonrecurrent cases includ ed 12 liposarcomas, 11 leiomyosarcomas, 4 rhabdomyosarcomas, and 4 mal ignant fibrohistiocytomas. The results show that the quantitative desc ription of chromatin patterns in Feulgen-stained nuclei made it possib le to distinguish between certain benign and malignant soft tissue tum ors. However, this was true only when specific histopathologic groups were taken into consideration. Indeed, the lipomas were markedly diffe rent from the liposarcomas, whereas the leiomyomas closely resembled t he leiomyosarcomas. The quantitative description of the chromatin patt erns also made it possible to identify certain clinically aggressive s oft tissue tumors. In this context, the authors observed that the chro matin pattern in the cell nuclei from the group of patients whose tumo rs had recurred less than 10 months after first surgery was significan tly more heterogeneous and less condensed than in the cell nuclei from patients whose tumors had recurred more than 10 months after this sur gery. In the same manner, the morphonuclear parameters under study mad e it possible to establish a more marked distinction between the primi tive and recurrent soft tissue tumors that developed a metastasis betw een 3 and 48 months after the diagnosis, and those tumors free of meta stasis until 38 months after the diagnosis. The former group exhibited cell nuclei with a chromatin pattern markedly more condensed and hete rogeneous than in the case of the cell nuclei belonging to the latter group.