Cytogenetic support for early malignant change in a diffuse neurofibroma not associated with neurofibromatosis

A 62-year-old woman presented with a solitary diffuse neurofibroma; a second recurrence showed features indicative of malignancy, but insufficient for a certain histologic diagnosis. Cytogenetic analysis revealed abnormalities previously described in malignant peripheral nerve sheath tumors and not in their benign counterparts, thus supporting the histologic suspicion of emerging malignancy.