Computer-assisted quantitative description of chromatin pattern in soft tissue tumors of the adult

The chromatin pattern in Feulgen-stained nuclei from soft tissue tumors was quantitatively described by means of computer-assisted microscope 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 49 malignant (31 primitive non-recurrent, 14 primitive locally recurrent, and 4 metastatic) cases. The 31 primitive nonrecurrent cases included 12 liposarcomas, 11 leiomyosarcomas, 4 rhabdomyosarcomas, and 4 malignant fibrohistiocytomas. The results show that the quantitative description of chromatin patterns in Feulgen-stained nuclei made it possible to distinguish between certain benign and malignant soft tissue tumors. However, this was true only when specific histopathologic groups were taken into consideration. Indeed, the lipomas were markedly different from the liposarcomas, whereas the leiomyomas closely resembled the leiomyosarcomas. The quantitative description of the chromatin patterns also made it possible to identify certain clinically aggressive soft tissue tumors. In this context, the authors observed that the chromatin pattern in the cell nuclei from the group of patients whose tumors had recurred less than 10 months after first surgery was significantly more heterogeneous and less condensed than in the cell nuclei from patients whose tumors had recurred more than 10 months after this surgery. In the same manner, the morphonuclear parameters under study made it possible to establish a more marked distinction between the primitive and recurrent soft tissue tumors that developed a metastasis between 3 and 48 months after the diagnosis, and those tumors free of metastasis until 38 months after the diagnosis. The former group exhibited cell nuclei with a chromatin pattern markedly more condensed and heterogeneous than in the case of the cell nuclei belonging to the latter group.