Cranial Nerve Ganglion Involvement Predicts Malignant Transformation of Plexiform Neurofibromas in Neurofibromatosis Type 1.

Abstract

Individuals with neurofibromatosis type 1 (NF1) have a 10% lifetime risk of developing malignant peripheral nerve sheath tumors (MPNSTs). The majority of NF1-associated MPNSTs arise from preexisting plexiform neurofibromas (PNFs). The PNF subtypes susceptible to malignant transformation remain unclear. This retrospective study included patients with head and neck PNFs who underwent surgical treatment at Shanghai Ninth People's Hospital from June of 2012 through July of 2023. Logistic regression analyses were conducted to assess risk factors for malignant transformation. Cox proportional hazards regression was used to evaluate the potential effects of variables on time to malignant transformation. A total of 19 (4%) of the 470 PNFs underwent malignant transformation. Deep or proximal PNFs involving cranial nerve ganglia were significantly associated with an increased risk of malignant transformation (adjusted odds ratio, 3.10 [95% CI, 1.07 to 9.00]); tumor morphology, relationship to adjacent tissues, and demographic factors were not significantly associated with malignant transformation. Ganglion involvement significantly accelerated the time to malignant transformation by 36% (hazard ratio, 7.20 [95% CI, 2.33 to 22.28]). Involvement of cranial nerve ganglion is an independent risk factor for malignant transformation of head and neck PNFs. Patients with this high-risk profile require closer surveillance for malignancies and proactive management of suspicious lesions.