Musculoskeletal Manifestations of Neurofibromatosis Type 1: a Pictorial Review
NSK Ip, CY Lee, MK Yuen
Hong Kong J Radiol 2018;21:213-21
DOI: 10.12809/hkjr1816856
Neurofibromatosis type 1 (NF1) is a common neurocutaneous condition with an autosomal dominant pattern of inheritance. It affects multiple organ systems, and musculoskeletal abnormalities are seen in up to 50% of affected patients. Neurofibromas are the hallmark of NF1. Of the three types of neurofibromas (localised, diffuse, and plexiform), plexiform neurofibromas are pathognomonic of NF1. There is a lifetime risk (around 8% to 13%) for NF1 patients of developing malignant peripheral nerve sheath tumours from pre-existing neurofibromas. Plexiform neurofibromas may be associated with massive and disfiguring enlargement of an extremity, a condition referred to as elephantiasis neuromatosa. Dermal neurofibromas usually appear as circumscribed masses on plain radiographs and cross-sectional imaging. In the axial skeleton, NF1 can affect the orbit (sphenoid wing dysplasia), chest wall (ribbon ribs deformity/thinned ribs), or spine (non-dystrophic and dystrophic scoliosis, dural ectasia). One of the most common manifestations in the appendicular skeleton is anterolateral bowing of the tibia with formation of pseudarthrosis after bowing fracture. NF1 is the most common phakomatosis and affects multiple organ systems; nearly all parts of the skeleton and surrounding soft tissues can be involved. Radiologists should be familiar with the different imaging manifestations of NF1.
Author affiliation(s):
NSK Ip, CY Lee, MK Yuen: Department of Radiology, Tuen Mun Hospital, Tuen Mun, Hong Kong
中文摘要
1型神經纖維瘤病的肌肉骨骼表現：圖像綜述
葉筱筠、李芷茵、袁銘強
1型神經纖維瘤病（NF1）是一種常見神經皮膚病，具有常染色體顯性遺傳模式。它影響多器官系統，高達50%患者出現肌肉骨骼異常。神經纖維瘤是NF1的顯著特點。在三種類型的神經纖維瘤中（局限型、瀰漫型和叢狀型），叢狀神經纖維瘤是NF1的特殊病癥。NF1患者已存在神經纖維瘤發展為惡性外周神經鞘瘤的終生風險約8%至13%。叢狀神經纖維瘤可導致肢體的重度畸型性肥大，後者稱為神經瘤性象皮病。皮膚神經纖維瘤通常在平片和橫斷面成像上顯示圓形包裹的腫塊。在軸向骨骼中，NF1可影響眼眶（蝶骨翼變形）、胸壁（帶狀肋骨畸形／肋骨變薄）或脊柱（非發育性或發育性脊柱側凸、硬膜擴張）。附肢骨骼中最常表現之一是脛骨的前外側彎曲，並在弓形骨折後形成假關節。NF1是最常見的皮膚病且影響多個器官系統，幾乎牽涉所有骨骼部分和周圍軟組織。放射科醫生應熟悉NF1的不同影像學表現。