Sporadic diffuse neurofibroma of the retropharyngeal space.

Neurofibroma (NF) rarely arises in the retropharyngeal space (RPS) of patients with or without Neurofibromatosis type I (NF-I). The diffuse subtype of NF (DNF) is characterized by an infiltrative growth pattern and typically involves the skin and subcutaneous tissue of the head and neck. We describe the clinic-pathologic features of a DNF involving the RPS of an adult without NF-I. To date, this subtype of NF has never been reported at this site.