Prognostic significance in malignant melanoma of nuclear DNA content measured by a microfluorimetric method

Identification of DAPI-stained normal, inflammatory, and carcinoma hepatic cells based on hyperspectral microscopy

Gross chromatin imbalance and high DNA content are distinct features of various types of cancer cells. However, severe inflammation can also produce similar symptoms in cells. In this study, normal, inflammatory, and carcinoma hepatic cells were stained with 4',6-diamidino-2-phenylindole (DAPI) and investigated by hyperspectral microscopy. DAPI is a DNA-sensitive fluorochrome. Therefore, the differences in the cellular DNA of the samples can be revealed by the corresponding fluorescence. Our experimental results demonstrate that although chromosomal disorder and high DNA content both occur in severely inflammatory and carcinoma hepatic cells, there is still a slight difference in their DNA, making their fluorescent intensity and even their spectral shapes distinguishable. Based on these spectral features, we developed a method for the precise identification of normal, inflammatory, and carcinoma hepatic cells in the field of view. The identification accuracy for these three types of cells was 99.8%. We believe that examination that combines DAPI staining with hyperspectral microscopy is a potential method for the identification and investigation of various types of cancer tissues.

Analysis of histopathological factors associated with prolonged survival of 10 years or more for patients with thick melanomas (> 5 mm)

AIMS

Although tumour thickness is the best predictor of melanoma prognosis in patients with localized cutaneous melanoma, prolonged survival occasionally occurs in patients with thick melanomas (> 5 mm). This study examined histological features which were associated with long-term survival.

METHODS AND RESULTS

Forty-two patients with thick, vertical growth phase melanomas surviving 10 years or more after diagnosis were matched by clinical stage of disease, sex, age and anatomical site of the primary lesion with 42 patients with similar characteristics who died from their disease within 3 years of diagnosis. Fourteen histological factors were assessed in both groups. Tumours with spindle cell and Spitz-like cell populations and those with low mitotic activity were significantly more frequently observed in long-term survivors. There was also a significant excess of melanomas exhibiting desmoplasia and those lacking vascular invasion in the long-term survivors.

CONCLUSIONS

These findings suggest that it may be useful to modify the current cutaneous melanoma classification on the basis of unusual cytological characteristics (as discussed at the recent 4th World Conference on Melanoma).