Multiple huge ancient neurilemmomas arising from superficial peroneal nerve: a case report

Neurilemmomas, also known as schwannomas, present as encapsulated, slow-growing, solitary, smooth-surfaced, and usually asymptomatic mass arising from Schwann cells of the nerve sheath surrounding cranial or peripheral nerves. They represent the most prevalent benign peripheral nerve sheath tumours and the occurrence in the upper extremity accounts for 12 to 19% and in the lower extremity for 13.5 to 17.5% of all cases. Schwannomas of the superficial peroneal nerve are very rare, and one can find in the literature only a few cases in the last 20 years. The smallest reported spinal giant schwannoma was of size 3 cm × 2 cm × 3 cm while the largest size reported of the same was 10 cm × 10 cm × 12 cm. We present a case report of a 54-year-old male with multiple huge ancient neurilemmomas arising from superficial peroneal nerve of 17 years’ duration. As the ultrasonography reported a hypoechoic mass in the left leg, antero-lateral muscular compartment with increased vascularity and magnetic resonance imaging (MRI) suggested large elongated lesion with multiple areas of haemorrhages; the primary diagnosis was made as vascular malformation. It was only after surgical exploration, three tumour masses were found arising from superficial peroneal nerve of sizes 15 × 6 cm, 2 × 2 cm, and 1 × 1 cm. The tumour was completely removed with meticulous dissection. Even though few fascicles of superficial peroneal nerve had to be sacrificed during excision, the patient recovered well with no neurological deficit. Level of evidence: Level V, therapeutic study.