Spiky/keratosis-pilaris-like early follicular mycosis fungoides: A clinicopathologic study of 20 cases with extended follow-up.

Backgrounds: Follicular mycosis fungoides (FMFs) is a distinct form of T-cell lymphoma whose course is considered aggressive.

Methods: A retrospective study with long-term follow-up of 20 patients diagnosed with spiky/keratosis-pilaris-like FMF between 2008 and 2017 was conducted.

Results: Twelve males and eight females were identified, with a mean age at first diagnosis of 59 years (range 42-86). Hyperkeratotic follicular papules were the sole clinical finding in 16 of 20 patients. A diagnostic delay between first symptom development and initial diagnosis was frequent (mean 42 months). The head/neck region was concurrently affected only in two patients. Disease stage at diagnosis was IA in two patients (10%) and IB in 18 (90%). Five patients had almost complete lesion regression, whilst there was only a slight improvement, without regression in 14. Two patients developed infiltrated papules, comedones, and small cysts during follow-up. Only one patient progressed to tumor stage (IIB) five years after the first diagnosis. The mean follow-up was seven years (range: 12-180 months). None of them died of cutaneous lymphoma.

Conclusions: FMF presenting with only spiky/keratosis-pilaris-like lesions have an excellent prognosis at medium-term follow-up. Early recognition of patients with this peculiar FMF presentation might lead to identifying prognostic factors.