A patient with leg numbness and a solitary Neurofibroma / Schwannoma at the popliteal fossa: A case reportz

Abstract

Neurofibroma/Schwannoma are common peripheral nerve sheath tumors related to Schwann cell’s proliferation, and are usually found in patients with neurofibromatosis type 1. Neurofibromatosis type 1, or von Recklinghausen’s disease, is diagnosed when two of the following symptoms are present: Neurofibroma, flecking over the groin or axilla, café au lait spots, optic glioma and Lisch nodules [1]. There are two types of Neurofibroma that arise from Schwann cells [1]. The solitary type, which is Neurofibroma are common peripheral nerve sheath tumors. Symptoms vary according to the site, including skin discoloration, disfiguration or neurologic deterioration. Neurofibroma cannot be seen on plain X-ray film unless they involve the bone and cause intraosseous lytic lesions. Ultrasonography plays an important role in the examination of soft tissue mass because it is inexpensive and has the advantage of being real-time for initial screening. In this study, we present a patient with a palpable mass over her right popliteal fossa. The texture of the mass was solid, without pulsation or fluctuation during palpation examination. There was no bruit on auscultation. Ultrasonography showed a well-defined, oval, solid and hypoechoic mass containing anechoic areas. Magnetic resonance imaging revealed the location of the tumor enveloped by the tibial nerve. An electro diagnostic study supported the impression of entrapped neuropathy at the right popliteal area. After surgical excision of the mass, pathological findings confirmed the diagnosis of Neurofibroma.