In our study, four DNA samples derived from formalin-fixed paraffin-embedded (FFPE) tissues were collected from a patient with MPNST-NF1-associated diagnosis, who presented conventional clinical features (>6 café-au-lait spots, Lisch nodules, axillary and inguinal freckling, cutaneous, subcutaneous and plexiform neurofibromas, optic glioma), and an atypical deletion in the NF1 gene. The gene discussed is NF1; the disease is plexiform neurofibroma.