Acneiform follicular mucinosis: an indolent follicular mucinosis variant unrelated to mycosis fungoides?

Follicular mucinosis (FM) can present as an acneiform eruption, and is usually a benign variant of primary FM unrelated to cutaneous T-cell lymphoma (CTCL). We report two cases of women in their twenties who presented with an acneiform rash on the face, arms and back. In both cases, pathological evaluation of the facial papules revealed predominantly mucinous degeneration of the follicular epithelium, with insufficient lymphocytic infiltration or atypia to diagnose mycosis fungoides. These cases are similar to previous reports of acneiform FM. As none of the reported cases progressed to CTCL, we consider that overdiagnosis and overtreatment should be avoided in acneiform FM, but recommend long-term follow-up.