Usefulness of flow cytometry in the diagnosis of mycosis fungoides.

BACKGROUND

The pathologic evaluation of mycosis fungoides (MF) is a challenging area in dermatopathology.

OBJECTIVE

We sought to determine the usefulness of flow cytometry for the diagnosis of MF from skin biopsy specimens.

METHODS

Skin biopsy specimens from 22 patients with a clinical suggestion for MF were evaluated by 4-color flow cytometry. The results were correlated with the International Society for Cutaneous Lymphoma (ISCL) MF diagnostic score and molecular studies for T-cell receptor gene rearrangement.

RESULTS

A T-cell abnormality by flow cytometry was identified in all 11 patients with diagnostic ISCL scores whereas the 7 patients with either subdiagnostic ISCL scores or reactive histology showed no phenotypic abnormality by flow cytometry. In all, 10 of 11 patients with diagnostic skin biopsy specimens for MF had T-cell receptor gene rearrangements by polymerase chain reaction. Gene rearrangements were not detected in the subdiagnostic group.

LIMITATIONS: Small study size was a limitation.

CONCLUSION

Flow cytometry of skin biopsy specimens is a sensitive method for detecting abnormalities in MF and should be considered part of the routine workup of patients with a clinical suggestion of MF.