Malignant Melanoma Cells and Hair Follicles

Objectives: The extension of atypical melanocytes to the hair follicle, also termed melanoma folliculotropism, is poorly evaluated and its role is contradictory. We performed an observational study focusing on anatomical areas rich in follicles, such as the head and neck region. Methods: Primary head and neck melanomas diagnosed in the Melanoma Unit, Policlinic Sant'Orsola-Malpighi, University of Bologna were analyzed. Folliculotropism was evaluated with a quantitative and morphologic parameter. Statistical analyses were performed correlating patients' prognosis with folliculotropism and other clinical and histopathologic factors. Results: The study was carried out on a sample of 62 patients. The diffuse distribution (atypical melanocytes present in more than three contiguous follicular units) correlated with scalp localization, nodular subtype, higher Breslow thickness, and a poorer prognosis. Conclusions: We believe that folliculotropism should be further investigated and reported by pathologists during the histologic diagnosis of melanoma.