Objectives: To clarify clinicopathologic features and reconcile discrepancies in previous studies of folliculotropic mycosis fungoides (FMF).
Design: A single-center retrospective clinicopathologic study and a systematic review of FMF.
Setting: Tertiary referral center in the midwestern United States.
Patients: Patients with clinical and histopathologic evidence of FMF seen at the tertiary referral center during a 12(1/2)-year period.
Main outcome measures: Clinicopathologic features of FMF.
Results: Fifty patients (32 male [64%] and 18 female [36%]) met study criteria for the clinicopathologic review. Pruritic patches, plaques, and folliculocentric lesions (milia, cysts, and alopecia) on the head, neck, and trunk were common clinical findings. The mean time to diagnosis of FMF was 5.0 years. Diagnostic latency did not affect risk of death. One-year and 5-year overall survival rates were 96% and 62%, respectively. Frequent microscopic features were follicular mucinosis (74%) and epidermotropism (54%). Systematic review of 186 additional patients confirmed male predominance (ratio of men to women, 3.2:1.0), prevalent pruritus (73%), frequent follicular mucinosis (69%) and epidermotropism (37%) microscopically, and common head, neck, and trunk involvement. Combined data demonstrated that 6% of patients with FMF had concurrent non-mycosis fungoides hematologic malignant neoplasms and that the 5-year overall survival rate was 62% to 64%.
Conclusion: Folliculotropic mycosis fungoides has distinct clinical and microscopic features and is associated with a poor 5-year overall survival rate.