Confocal Microscopy Predicts the Risk of Recurrence and Malignant Transformation of Mucocutaneous Neurofibromas in NF-1: An Observational Study

From 2005 to 2010, 20 consecutive patients with fully manifested neurofibromatosis type 1 (NF1) underwent elective neurofibroma resection at our institution (Departments of Plastic Surgery and of Odontostomatology). Specimens were photographed under optical microscope and confocal laser scanning microscopy (CLSM) with ultra-high accuracy of detail, including depth of field. Patients were followed up for a minimum of 4 years and up to a maximum of 12 years, postsurgery. While all nonrecurring lesions showed intense fluorescence, six of the seven lesions with absence of fluorescence under CLSM recurred at a mean of 5.5 years after surgical excision. Among the re-excised lesions, 3 were diagnosed as malignant at the subsequent removal. Despite the limitation of a small cohort, CLSM appears to be a simple and low-cost technique to differentiate forms of neurofibromas with low and high risk of recurrence and malignant degeneration.