Quantitative electron microscopy in the diagnosis of mycosis fungoides. A simple analysis of lymphocytic nuclear convolutions.

In the present study we compared the accuracy of three different ultrastructural methods used to confirm clinically proved cases of mycosis fungoides (MF) from skin biopsy specimens. Method 1 is a qualitative method and confirmed the diagnosis of MF in only 44% of the patients with MF. Method 2 involved image analysis of lymphocytic nuclei and confirmed the diagnosis of MF in only 67% of the patients with MF. The most sensitive ultrastructural method for confirming the diagnosis of MF was a simple scoring of the number of sharply angled nuclear invaginations in 100 lymphocytes (method 3). Control biopsy specimens had many more lymphocytes (19% to 55%) with no sharply angled nuclear invaginations compared with those from patients with MF (3% to 15%). The clinical diagnosis of MF was confirmed in 100% of our patients with MF using method 3.