Schwannoma Presenting with Anteromedial Knee Pain and Bone Defect

Abstract

Tumors of the peripheral nerve sheath including schwannomas are known for their rarity and can present with neurological deficit. We report an interesting case of schwannoma of the infrapatellar branch of saphenous nerve presenting with anteromedial knee pain and proximal tibial metaphyseal defect. A 26-year-old man presented with pain and swelling (for the past 2 months) in the anteromedial aspect of knee. Investigations revealed scalloping lesion in the anteromedial aspect of proximal tibia with sclerosed margins. Surgical exploration identified an encapsulated tumor lying over the defect in the proximal tibial metaphysis. Histopathological examination confirmed benign schwannoma and the patient became symptom-free after the surgery. Schwannoma of the infrapatellar branch of saphenous nerve can present with anteromedial knee pain. In patients with an eccentrically placed metaphyseal defect of the anteromedial tibia with sclerosed smooth margins, the possibility of nerve sheath tumors should always be considered.

Successful management of a rare radius schwannoma mimicking malignant bone tumors: A case report and literature review

“…the primary disease might only be diagnosed when the tumor grows with local swelling, pain, neurological deficits, and pathological fractures (12). As a result, long-term slow-growing encapsulated tumors could unknowingly result in bone destruction and defects.…”