Abstract

We present the case of an adolescent with an intramuscular ancient schwannoma of the axillary nerve which, to the best of our knowledge, has not been reported before. Due to its deep location, intramuscular schwannoma has less clinical signs and hence, is difficult to diagnose. Ancient schwannoma, characterised by degeneration due to long course, is rare and can be mistaken for malignancy due to heterogeneous intensity and degeneration evident on MRI and nuclear atypia on histopathology. It is important to differentiate it from malignancy based on a clinically benign swelling with a long history, well-encapsulated mass on MRI with the split fat sign and absence of significant mitotic activity despite nuclear atypia. The aim of surgery should be enucleation of the tumour while preserving the function of the parent nerve.