Milia in regressing plaques of mycosis fungoides: provoked by topical nitrogen mustard or not?

OBJECTIVE: To report three cases of mycosis fungoides with milia formation in the regressing lesions.

PATIENTS AND SETTING: Dermatology clinic of a university hospital (referral center). Three patients with mycosis fungoides with body surface involvement of 10% in one case (stage IIb) and exceeding 30% in two cases (stages IIb and III). All patients were treated with photochemotherapy and topical nitrogen mustard ointment in a concentration of 0.01%. After approximately 3 months multiple milia erupted on regressing plaques.

RESULTS: The presence of milia was evident and was confirmed by histopathology. Regression of mycosis fungoides was noted in these plaques both clinically and in comparison with the pretreatment histologic appearance. Two of the patients showed a histological picture of follicular mucinosis.

CONCLUSIONS: We do not know the significance of milia in mycosis fungoides (MF). However, we suggest that follicular rupture or a degenerative process might result in milia formation.