Desmoid tumours of the brachial plexus are rare and may occur in extra-abdominal sites. The tumours are of fibroblastic origin and, although benign, are locally aggressive. Their relationship to critical neurovascular structures in their anatomic locations presents a challenge to the operating surgeons trying to adhere to the principles of surgery. Surprisingly little neurosurgical literature exists which was devoted to this topic despite the challenge these lesions present in surgery both at surgery and in choosing adjuvant therapies. We report a case of a large brachial plexus tumour in a patient which was diagnosed radiologically and histopathologically and the patient underwent surgical excision with good outcome. Desmoid tumours histologically are benign and are usually composed of proliferating, benign fibroblasts in an abundant matrix of collagen. They do not transform into malignant tumours or metastasize. Surgery is the mainstay of treatment; however, adjuvant radiation and chemotherapy remain controversial. 1. Introduction Many terms have been used to refer to desmoids tumours over the years, including fibromatosis, desmoid tumors, and aggressive fibromatosis. However, “Desmoid-type fibromatosis” has emerged as the designation of choice by the World Health Organization . A review of the literature identified three case series reporting the treatment of desmoids tumours involving the brachial plexus. The first series, reported by Binder et al.  in June 2004, served to ascertain the rarity of these tumours. Twenty-four patients were treated at the University of California, San Francisco, CA, USA, who had primary brachial plexus tumours and only one (4%) had a desmoid tumour. The second case series reported by Seinfeld et al.  in 2006 included four cases of desmoid-type fibromatosis involving the brachial plexus. This series additionally assessed these lesions for mutations in the c-KIT oncogene in hopes of establishing a basis for predicting which of these lesions would respond to the chemotherapy agent imatinib mesylate. In the third case series, Dafford et al.  in June 2007 undertook a retrospective study of 15 desmoid tumors in 11 women and four men (ranging in age from 32 to 67 years; median 48 years) treated at their institution. In this study, the results were that there were 13 patients (86%) with brachial plexus lesions. In this review, we document the clinical presentation, neuroimaging, surgical, and pathological findings in a patient with a desmoid tumour arising from the brachial plexus. 1.1. Age and Gender Incidences of
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