A rare case of giant intercostal nerve schwannoma

Abstract

Schwannomas are benign peripheral nerve sheath tumours that most commonly affect spinal and cranial nerves, while their occurrence along intercostal nerves is exceedingly rare. Giant schwannomas, those exceeding 5 cm in diameter, can exert significant mass effect on adjacent structures, causing pain, neurological symptoms, or respiratory compromise. We present the case of a 33-year-old woman referred to the Royal National Orthopaedic Hospital with a symptomatic 10 cm soft tissue mass arising from the left 7th intercostal nerve. Preoperative magnetic resonance imaging (MRI) revealed an intramuscular, septated lesion with atypical imaging characteristics, prompting differential diagnoses including sarcoma. Core biopsy confirmed a benign schwannoma. The patient reported persistent pain, hypersensitivity, and early satiety. Surgical excision was performed via an anterolateral chest wall approach with meticulous dissection to preserve surrounding nerves and pleura. Histopathology confirmed a benign schwannoma with characteristic spindle cell architecture and S100 protein positivity. Postoperative recovery was uneventful, with resolution of symptoms and no neurological deficit. This case highlights the diagnostic challenge posed by giant intercostal schwannomas and the importance of thorough imaging, histological evaluation, and surgical planning. Despite their benign nature, giant schwannomas can cause significant morbidity, warranting timely surgical intervention. Multidisciplinary management involving orthopaedic surgeons, radiologists, and histopathologists is essential to optimise outcomes. Our report adds to the limited literature on giant intercostal nerve schwannomas and underscores the need for heightened clinical suspicion when evaluating large intrathoracic soft tissue masses with atypical radiographic features.