Evaluation of the prognostic significance of follicular extension in actinic keratoses.

Abstract

OBJECTIVE: To determine the prognostic significance of follicular extension in actinic keratosis. DESIGN: Retrospective, case-controlled study. SETTING: Mount Sinai Dermatopathology Services. PATIENTS/PARTICIPANTS: Out of a randomly selected pool of 1,000 biopsies, 104 cases of actinic keratosis with follicular extension and 104 cases of actinic keratosis without follicular extension were chosen for the study (56.7% male; mean [SD] age, 67.5 [11.8] years; age range, 28-93). MAIN OUTCOME MEASURES: Presence of follicular extension and location of the actinic keratosis. Age and gender of the patient. Number of previously diagnosed squamous cell carcinomas, basal cell carcinomas, and melanomas per patient. RESULTS: Patients with follicular extension of actinic keratosis were 1.8 times more likely to have a previous history of invasive carcinoma than patients without follicular extension. Patients with follicular extension were 11 times more likely to have a previous history of invasive melanoma than patients with actinic keratoses without follicular extension. Patients with follicular extension were more likely to be male, had an older average age, and more often presented with lesions on their leg when compared to patients with actinic keratoses lacking follicular extension. CONCLUSION: Patients presenting with actinic keratoses with follicular extension were more likely to have increased risk factors for skin cancer. These findings have implications for identifying patient factors predictive of progression of actinic keratosis to invasive carcinoma, providing potentially valuable patient screening guidelines.