Giant Plexiform Neurofibroma of the Perineum and Pelvic Cavity Manifesting as Segmental Neurofibromatosis.

Segmental neurofibromatosis (SN) is rare form of neurofibromatosis characterized that cutaneous or neural changes are limited to one region of the body. SN present neurofibroma and less frequently, café au lait macules (CALMs) on usually unilateral or rarely bilateral of the body region. SN seems to have fewer systemic complications than neurofibromatosis type I or II, except patients with plexiform neurofibromas (PNFs). PNFs are rare benign peripheral nerve sheath tumors which arise from single or multiple nerves. PNFs can easily become aggressive growth particularly during puberty or pregnancy and leading to disfigurement and functional impairment. Also, PNFs can transform to malignant peripheral nerve sheath tumor, higher rate than classic neurofibroma. So, it is important to decide appropriate treatment modalities and time to intervention.