Gastrointestinal stromal tumour with a KIT exon 11 mutation presenting as a paratesticular mass

Gastrointestinal stromal tumours (GISTs) are sarcomas arising in the gastrointestinal tract. They are characterised by a gain in function mutation of the KIT oncogene and the majority express the receptor tyrosine kinase KIT, which can be detected by the immunohistochemical stain CD117. Patients with a GIST present with symptoms such as abdominal pain or gastrointestinal bleeding, or may be asymptomatic. We describe the clinical history and pathological features of a patient with a GIST who presented with a paratesticular mass which, to our knowledge, has never previously been reported. With the development of new drugs to treat GISTs, the knowledge of the type of mutations may in the future prove helpful in determining optimal treatment strategies and prognosis.