THE DIAGNOSTIC-VALUE OF MORPHOMETRY ON BLOOD-LYMPHOCYTES IN ERYTHRODERMIC ACTINIC RETICULOID

Background: As the differential diagnosis of erythrodermic actinic ret iculoid vs Sezary syndrome (SS) can be very difficult, we examined the value of the nuclear contour index (NCI) on blood lymphocytes as the criterion for differential diagnoses. The NCI is defined as the nuclea r parameter divided by the square root of the nuclear area. Three diff erent parameters were studied: mean NCI, percentage of cells with an N CI of 6.5 or greater, and the highest NCI. These indexes were studied on blood lymphocyte samples obtained from 10 patients with erythroderm ic actinic reticuloid and were compared with the findings in 10 patien ts with other benign forms of erythroderma and in seven patients suffe ring from SS. Results: The patients with erythrodermic actinic reticul oid differed significantly from the group with SS regarding the percen tage of cells with an NCI of 6.5 or greater and the highest NCI, but n ot when the mean NCI was considered. All three parameters revealed non significant results for erythrodermic actinic reticuloid compared with other benign forms of erythroderma. The group with SS differed signif icantly from the patients with other benign forms of erythroderma rega rding all three parameters. By combining three morphometric criteria ( mean NCI, greater than or equal to 5.5; > 30% lymphoid cells with an N CI of greater than or equal to 6.5; and highest NCI, greater than or e qual to 11.5), all patients with erythrodermic actinic reticuloid or o ther benign forms of erythroderma and six of the seven patients with S S were correctly classified. Conclusion: Our data indicate that assess ment of the NCI on peripheral blood lymphocytes is of value in the dif ferential diagnosis of erythrodermic actinic reticuloid vs SS.