The value of nuclear contour index in the diagnosis of mycosis fungoides. An assessment of current ultrastructural morphometric diagnostic criteria.

Skin biopsy specimens from 43 patients with established mycosis fungoides (MF) and 28 with non-MF lymphoid skin infiltrations were studied by transmission electron microscopy. The nuclear contour index (NCI) of infiltrating lymphoid cells was obtained by means of a Zeiss Videoplan computer and measuring tablet. Classification of the material into MF and non-MF groups was done according to the diagnostic criteria used by McNutt et al. (1980, 1981) and Meijer et al. (1980); this study evaluates the usefulness of these previously published criteria based on quantitative electron microscopy. Statistical analysis confirmed that the mean NCI (MNCI) of the lymphoid cells of patients with MF is significantly greater than that in patients with other lymphoid infiltrates (P less than 0.001). However, all published diagnostic criteria (McNutt et al., 1980, 1981, and Meijer et al., 1980) tested in the authors' larger patient population yielded lower sensitivity than has been reported. The diagnostic criteria based on values of MNCI, percentage of lymphoid cells with NCI greater than 7, and percentage of lymphoid cells with nuclear profile area of greater than 30 microns2 reported by McNutt et al. (1981) appear to be better than others, and provide the highest sensitivity rate, which is in the range of 44% to 47%. There were no false-positive findings. It was concluded that the use of ultrastructural morphometry according to the techniques and diagnostic criteria of McNutt et al. (1981) is useful in the diagnosis of MF.