Pathological study of pigmented dermatofibrosarcoma protuberans.

In this paper we performed morphological studies of Bednar tumor, which is a rare pigmented variant of dermatofibrosarcoma protuberans (DFSP) for evidence of histogenetic origin. Presence of melanosome-containing cells is the only histologic criterion of Bednar tumor, which is different from the ordinary DFSP. Immunohistochemical and ultrastructural examinations revealed that the melanosome-containing cells gave positive reactivity to antibodies to vimentin and S-100 protein, but negative to HMB-45, CD38, Factor VIII, NSE, and KP-1. The melanosomes are in Stage II, III, and IV, suggesting that the pigment was produced within the cell rather than phagocytosed from other cells. The rest of the tumor had similar pattern of immunoreactivity to DFSP such as positivity for CD34 and vimentin, indicating that Bednar tumor and DFSP originated from the same cell line. The ultrastructural feature of non-pigmented cells was similar to perineural cells in the first group and similar to fibroblasts in the second group. DNA flow cytometry in our cases revealed diploid cells with low to intermediate S-phase fraction and no aneuploid cells which were reported in a previous study.

DNA analysis of hepatocellular carcinoma.

Specimens from 13 cases of resectable hepatocellular carcinoma (HCC) were studied using flow cytometry. The correlation between histological features and ploidy distribution showed those with higher histological grading (HCC grade III or IV) to display an increased tendency towards aneuploidy and polyploidy than those with low grade (HCC grade II and clear cell type of HCC). Along with the tumor’s increased tendency towards aneuploidy and polyploidy, the percent DNA distribution in the S- and G2 – phase was also found increased. The same applied to the DNA index, we also detected a strong correlation between proliferation index and ploidy pattern of HCC.

Hepatocellular carcinoma: Correlation of histological grading with immunohistochemical identification of proliferative hepatocytes with PC 10.

Sections from 31 liver needle biopsies of hepatocellular carcinomas(HCCs) were exa-mined for the histological grading of tumors with the expression of a labelling index, using monoclonal antibodies to proliferating cell nuclear antigen PC-10. The correlation between histological grading and the labelling index showed a statistically significant increase in the labelling index in grades III to IV of HCCs. A cut-off point of the labelling index at 49 per cent was proposed to indicate the prognosis of the patient. HCCs with a labelling index below 49 per cent has a better prognosis than HCCs with a labelling index above 49 per cent. A combination of histological grading and the labelling index indicated the prognosis of the patients with HCCs.

Immunohistochemical and ultrastructural studies of myofibroblasts in hepatocellular carcinoma.

Sections from 13 hepatocellular carcinomas (HCCs) were examined to determine the myofibroblasts (MFBs) in tumour fibrous stroma and cirrhotic fibrous stroma, using monoclonal antibodies to specific actins HHF-35, 1A4 and sarcomeric actin. Histological grading of tumours with the expression of a labelling index using monoclonal antibodies to proliferative cell nuclear antigen (PC-10) were correlated with the amount of MFBs. The results showed a statistically significant increase in the amount of MFBs in tumour fibrous stroma. However, no significant correlation was found between the amount of MFBs with histological grading or the labelling index. However, a good correlation with statistically significant differences between the histological grading of HCC with the labelling index was shown. In conclusion, MFBs found in the tumour fibrous septa of HCC were a response by the stromal reaction or a desmoplastic reaction intended to limit the tumour size by contraction.