Fluorine-18-2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography Masquerading as a Case of Sporadic Malignant Peripheral Nerve Sheath Tumor of Lower Extremity Presenting as Massive Lower Limb Edema.

Malignant peripheral nerve sheath tumors (MPNSTs) are rare neuroectodermal tumors resulting from the malignant transformation of benign plexiform neurofibromas. The sporadic form of these tumors is rare than familial variants (seen in neurofibromatosis Type 1) and making the diagnosis difficult. We are presenting a case of 40--year-old female with the complaint of progressive swelling of lower limb with initial suspicion of lymphedema and underwent lymphoscintigraphy, magnetic resonance imaging, and finally fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography scans were done to rule out mitotic etiology and extent of the disease. The patient underwent below-knee amputation, and histopathological examination confirmed the diagnosis of sporadic MPNST.