A Scoring System Based on Differentially Weighted Criteria for Establishing a Standardized Threshold for the Diagnosis of Early Mycosis Fungoides

Abstract

The threshold for the early diagnosis of the mycosis fungoides form of cutaneous T cell lymphoma (MF-CTCL) is indistinct, and varies from center to center, because there is no “gold standard” for this diagnosis. Neither the clinical nor the histologic features allow all cases to be diagnosed in the early patch/plaque forms of the disease. Adjunctive tests of high specificity but low sensitivity are now coming into increasing clinical use; these appear to have value in making this diagnosis. A scoring system is now proposed that standardizes the threshold for the diagnosis of MF-CTCL in its early stages. Scores are assigned according to the strength of clinical morphology (2 point maximum), distribution (2 point maximum), and histology (3 point maximum) with regard to likelihood of MF-CTCL. A threshold of 5 points is defined as the inclusion point. Additional points (2 points each, up to a maximum of 4 points) can be gathered in support of the diagnosis if highly specific adjunctive tests (i.e., Pan T cell marker discordance, T cell receptor gene rearrangement, Sézary cells in the blood, elevated nuclear contour index, or aneuploidy) are positive. It is proposed that application of standardized threshold criteria to characterize patients entered into studies of pathogenesis, diagnosis, therapy, or prognostication will standardize Stage I MF-CTCL patients, allowing better comparisons of studies executed at different centers, and will homogenize patient entry into multi-center protocols.