41.: A rare cause of secondary headache

We outline a case report of primary central nervous system lymphoma which exhibited a rare immunophenotype of T cell origin with an aggressive clinical course and poor prognosis. We emphasize the use of immunohistochemistry in diagnosing this rare tumour and discuss response to treatment and prognosis. The patient deteriorated and died rapidly from this aggressive tumour. The poster will aim to illustrate the importance of imaging coupled with immunohistochemistry in diagnosing this rare tumour. Primary central nervous system lymphoma of T cell origin in this case was associated with a poor clinical outcome with limited response to treatment.