A Huge Malignant Peripheral Nerve Sheath Tumor Revealing Von Recklinghausen's Disease

Only a few cases of malignant peripheral nerve sheath tumor (MPNST) associated with Von Recklinghausen’s disease or type I neurofibromatosis (NF-1) have so far been reported worldwide. We present a case of a 27 year old man with MPNST of the left thigh associated with NF-1. The diagnosis was based on clinical, radiological and histopathological evidence. He presented a large mass of thigh, deeply adhering, with the presence of collateral venous circulation. He also presented multiple cafe-au-lait spots, with a many neurofibromas. MRI of the hip and left thigh showed the presence of a bulky tissue process, badly limited, measuring 24,6×11×12 cm occupying the anterolateral and posterolateral lodge with an intermediate signal in T1, discreetly more intense in T2. The microscopic and immunohistochemical findings supported the final diagnosis of MPNST with mesenchymal differentiation. The staging was negative. Also, the diagnosis of NF-1 is held according to the presence of two NIH criteria. The decision of the multidisciplinary meeting was to make a neoadjuvant chemotherapy to surgery with a doublet of adriamycin and ifosfamide with surveillance for other tumor development or multisystem complications. The presence of a large mass on the path of a peripheral nerve requires a careful examination of the skin for signs evoking a von Recklinghausen disease.