Surgery for atypical plexiform neurofibromas of the trunk in NF1 with high standardised uptake value (SUV) in positron-emission tomography (PET) expressing podoplanin: a long-term follow-up.

A 23-year-old female with an established diagnosis of neurofibromatosis type 1 (NF1) was found to have two tumours in her trunk. These showed high uptake value in positron-emission/computerized tomography (PET) scans, and were suspected to be malignant peripheral nerve sheath tumours (MPNST). The extirpated tumours proved to be atypical plexiform neurofibromas. Slight to moderate podoplanin expression of the tumour cells was noted in areas of fibrillary growth. Six years following surgery, there is neither evidence of local tumour recurrence nor development of MPNST. Current studies on atypical neurofibroma in NF1 suggest podoplanin expression in subtypes of transformed Schwann cells, resembling schwannoma-like areas in neurofibroma. This marker may be useful in distinguishing different Schwann cell populations in NF1.